been observed in patients receiving tenofovir df with didanosine 400 mg daily. in patients weighing greater than 60 kg, the didanosine dose should be reduced to 250 mg when it is coadministered with truvada. data are not available to recommend a dose adjustment of didanosine for adult or pediatric patients weighing less than 60 kg. when coadministered, truvada and videx ec may be taken under fasted conditions or with a light meal (less than 400 kcal, 20% fat). 7.2 hiv-1 protease inhibitors tenofovir decreases the auc and cmin of atazanavir [see clinical pharmacology (12.3)]. when coadministered with truvada, it is recommended that atazanavir 300 mg is given with ritonavir 100 mg. truvada should not be coadministered with atazanavir without ritonavir. lopinavir/ritonavir, atazanavir coadministered with ritonavir, and darunavir coadministered with ritonavir have been shown to increase tenofovir concentrations [see clinical pharmacology (12.3)]. tenofovir df is a substrate of p-glycoprotein (p-gp) and breast cancer resistance protein (bcrp) transporters. when tenofovir df is coadministered with an inhibitor of these transporters, an increase in absorption may be observed. patients receiving truvada concomitantly with lopinavir/ritonavir, ritonavir-boosted atazanavir, or ritonavir-boosted darunavir should be monitored for tenofovir df-associated adverse reactions. truvada should be discontinued in patients who develop tenofovir df-associated adverse reactions. 7.3 hepatitis c antiviral agents coadministration of truvada and epclusa® (sofosbuvir/velpatasvir) or harvoni®(ledipasvir/sofosbuvir has been shown to increase tenofovir exposure [see clinical pharmacology (12.3)]. in patients receiving truvada concomitantly with epclusa, monitor for adverse reactions associated with tenofovir df. in patients receiving truvada concomitantly with harvoni without an hiv-1 protease inhibitor/ritonavir or an hiv-1 protease inhibitor/cobicistat combination, monitor for adverse reactions associated with tenofovir df. in patients receiving truvada concomitantly with harvoni and an hiv-1 protease inhibitor/ritonavir or an hiv-1 protease inhibitor/cobicistat combination, consider an alternative hcv or antiretroviral therapy, as the safety of increased tenofovir concentrations in this setting has not been established. if coadministration is necessary, monitor for adverse reactions associated with tenofovir df. 7.4 drugs affecting renal function emtricitabine and tenofovir are primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion [see clinical pharmacology (12.3)]. no drug-drug interactions due to competition for renal excretion have been observed; however, coadministration of truvada with drugs that are eliminated by active tubular secretion may increase concentrations of emtricitabine, tenofovir, and/or the coadministered drug. some examples include, but are not limited to, acyclovir, adefovir dipivoxil, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple nsaids [see warnings and precautions (5.2)]. drugs that decrease renal function may increase concentrations of emtricitabine and/or tenofovir.

pre-exposure prophylaxis (prep) to reduce the risk of sexually acquired hiv-1 in adults at high risk. this indication is based on clinical trials in men who have sex with men (msm) at high risk for hiv-1 infection and in heterosexual serodiscordant couples [see clinical studies (14.2, 14.3)]. when considering truvada for pre-exposure prophylaxis the following factors may help to identify individuals at high risk: has partner(s) known to be hiv-1 infected, or engages in sexual activity within a high prevalence area or social network and one or more of the following: inconsistent or no condom use diagnosis of sexually transmitted infections exchange of sex for commodities (such as money, food, shelter, or drugs) use of illicit drugs or alcohol dependence incarceration partner(s) of unknown hiv-1 status with any of the factors listed above when prescribing truvada for pre-exposure prophylaxis, healthcare providers must: prescribe truvada as part of a comprehensive prevention strategy because truvada is not always effective in preventing the acquisition of hiv-1 infection [see warnings and precautions (5.8)]; counsel all uninfected individuals to strictly adhere to the recommended truvada dosing schedule because the effectiveness of truvada in reducing the risk of acquiring hiv-1 was strongly correlated with adherence as demonstrated by measurable drug levels in clinical trials [see warnings and precautions (5.8)]; confirm a negative hiv-1 test immediately prior to initiating truvada for a prep indication. if clinical symptoms consistent with acute viral infection are present and recent (<1 month) exposures are suspected, delay starting prep for at least one month and reconfirm hiv-1 status or use a test approved by the fda as an aid in the diagnosis of hiv-1 infection, including acute or primary hiv-1 infection [see warnings and precautions (5.8)]; and screen for hiv-1 infection at least once every 3 months while taking truvada for prep.

tenofovir are principally eliminated by the kidney. renal impairment, including cases of acute renal failure and fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been reported with the use of viread [see adverse reactions (6.3)]. it is recommended that estimated creatinine clearance be assessed in all individuals prior to initiating therapy and as clinically appropriate during therapy with truvada. in patients at risk of renal dysfunction, including patients who have previously experienced renal events while receiving hepsera®, it is recommended that estimated creatinine clearance, serum phosphorus, urine glucose, and urine protein be assessed prior to initiation of truvada, and periodically during truvada therapy. truvada should be avoided with concurrent or recent use of a nephrotoxic agent (e.g., high-dose or multiple non-steroidal anti-inflammatory drugs [nsaids]) [see drug interactions (7.4)]. cases of acute renal failure after initiation of high-dose or multiple nsaids have been reported in hiv-infected patients with risk factors for renal dysfunction who appeared stable on tenofovir df. some patients required hospitalization and renal replacement therapy. alternatives to nsaids should be considered, if needed, in patients at risk for renal dysfunction. persistent or worsening bone pain, pain in extremities, fractures, and/or muscular pain or weakness may be manifestations of proximal renal tubulopathy and should prompt an evaluation of renal function in at-risk patients. treatment of hiv-1 infection dosing interval adjustment of truvada and close monitoring of renal function are recommended in all patients with estimated creatinine clearance 30–49 ml/min [see dosage and administration (2.4)]. no safety or efficacy data are available in patients with renal impairment who received truvada using these dosing guidelines, so the potential benefit of truvada therapy should be assessed against the potential risk of renal toxicity. truvada should not be administered to patients with estimated creatinine clearance below 30 ml/min or patients requiring hemodialysis. pre-exposure prophylaxis truvada for a prep indication should not be used if estimated creatinine clearance is less than 60 ml/min. if a decrease in estimated creatinine clearance is observed in uninfected individuals while using truvada for prep, evaluate potential causes and re-assess potential risks and benefits of continued use [see dosage and administration (2.4)]. 5.3 lactic acidosis/severe hepatomegaly with steatosis lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs, including tenofovir df and emtricitabine, components of truvada, alone or in combination with other antiretrovirals. treatment with truvada should be suspended in any patient or uninfected individual who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations). 5.4 coadministration with other products truvada is a fixed-dose combination of emtricitabine and tenofovir df. do not coadminister truvada with other drugs containing emtricitabine, tenofovir df, or tenofovir alafenamide, including atripla, complera, descovy, emtriva, genvoya, odefsey, stribild, vemlidy, or viread. due to similarities between emtricitabine and lamivudine, do not coadminister truvada with other drugs containing lamivudine, including combivir (lamivudine/zidovudine), dutrebis (lamivudine/raltegravir), epivir or epivir-hbv (lamivudine), epzicom (abacavir sulfate/lamivudine), triumeq (abacavir sulfate/dolutegravir/lamivudine), or trizivir (abacavir sulfate/lamivudine/zidovudine). do not coadminister truvada with hepsera (adefovir dipivoxil). 5.5 bone effects of tenofovir df bone mineral density in clinical trials in hiv-1 infected adults and in a clinical trial of hiv-1 uninfected individuals, tenofovir df was associated with slightly greater decreases in bone mineral density (bmd) and increases in biochemical markers of bone metabolism, suggesting increased bone turnover relative to comparators [see adverse reactions (6.2) and viread prescribing information]. serum parathyroid hormone levels and 1,25 vitamin d levels were also higher in subjects receiving tenofovir df. clinical trials evaluating tenofovir df in pediatric and adolescent subjects were conducted. under normal circumstances, bmd increases rapidly in pediatric patients. in hiv-1 infected subjects aged 2 years to less than 18 years, bone effects were similar to those observed in adult subjects and suggest increased bone turnover. total body bmd gain was less in the tenofovir df treated hiv-1 infected pediatric subjects as compared to the control groups. similar trends were observed in chronic hepatitis b infected adolescent subjects aged 12 years to less than 18 years. in all pediatric trials, skeletal growth (height) appeared to be unaffected. for more information, consult the viread prescribing information. the effects of tenofovir df-associated changes in bmd and biochemical markers on long-term bone health and future fracture risk are unknown. assessment of bmd should be considered for adult and pediatric patients who have a history of pathologic bone fracture or other risk factors for osteoporosis or bone loss. although the effect of supplementation with calcium and vitamin d was not studied, such supplementation may be beneficial. if bone abnormalities are suspected then appropriate consultation should be obtained. mineralization defects cases of osteomalacia associated with proximal renal tubulopathy, manifested as bone pain or pain in extremities and which may contribute to fractures, have been reported in association with the use of tenofovir df [see adverse reactions (6.3)]. arthralgias and muscle pain or weakness have also been reported in cases of proximal renal tubulopathy. hypophosphatemia and osteomalacia secondary to proximal renal tubulopathy should be considered in patients at risk of renal dysfunction who present with persistent or worsening bone or muscle symptoms while receiving products containing tenofovir df [see warnings and precautions (5.2)]. 5.6 immune reconstitution syndrome immune reconstitution syndrome has been reported in hiv-1 infected patients treated with combination antiretroviral therapy, including truvada. during the initial phase of combination antiretroviral treatment, hiv-1 infected patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as mycobacterium avium infection, cytomegalovirus, pneumocystis jirovecii pneumonia [pcp], or tuberculosis), which may necessitate further evaluation and treatment. autoimmune disorders (such as graves' disease, polymyositis, and guillain-barré syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable and can occur many months after initiation of treatment. 5.7 early virologic failure clinical trials in hiv-1 infected subjects have demonstrated that certain regimens that only contain three nucleoside reverse transcriptase inhibitors (nrtis) are generally less effective than triple drug regimens containing two nrtis in combination with either a non-nucleoside reverse transcriptase inhibitor (nnrti) or a hiv-1 protease inhibitor. in particular, early virologic failure and high rates of resistance substitutions have been reported. triple nucleoside regimens should therefore be used with caution. patients on a therapy utilizing a triple nucleoside-only regimen should be carefully monitored and considered for treatment modification. 5.8 comprehensive management to reduce the risk of acquiring hiv-1 use truvada for pre-exposure prophylaxis only as part of a comprehensive prevention strategy that includes other prevention measures, such as safer sex practices, because truvada is not always effective in preventing the acquisition of hiv-1 [see clinical studies (14.2 and 14.3)]. counsel uninfected individuals about safer sex practices that include consistent and correct use of condoms, knowledge of their hiv-1 status and that of their partner(s), and regular testing for other sexually transmitted infections that can facilitate hiv-1 transmission (such as syphilis and gonorrhea). inform uninfected individuals about and support their efforts in reducing sexual risk behavior. use truvada to reduce the risk of acquiring hiv-1 only in individuals confirmed to be hiv-negative. hiv-1 resistance substitutions may emerge in individuals with undetected hiv-1 infection who are taking only truvada, because truvada alone does not constitute a complete treatment regimen for hiv-1 treatment [see microbiology (12.4)]; therefore, care should be taken to minimize drug exposure in hiv-infected individuals. many hiv-1 tests, such as rapid tests, detect anti-hiv antibodies and may not identify hiv-1 during the acute stage of infection. prior to initiating truvada for a prep indication, evaluate seronegative individuals for current or recent signs or symptoms consistent with acute viral infections (e.g., fever, fatigue, myalgia, skin rash) and ask about potential exposure events (e.g., unprotected, or condom broke during, sex with an hiv-1 infected partner) that may have occurred within the last month. if clinical symptoms consistent with acute viral infection are present and recent (<1 month) exposures are suspected, delay starting prep for at least one month and reconfirm hiv-1 status or use a test approved by the fda as an aid in the diagnosis of hiv-1 infection, including acute or primary hiv-1 infection. while using truvada for a prep indication, hiv-1 screening tests should be repeated at least every 3 months. if symptoms consistent with acute hiv-1 infection develop following a potential exposure event, prep should be discontinued until negative infection status is confirmed using a test approved by the fda as an aid in the diagnosis of hiv-1, including acute or primary hiv-1 infection. counsel uninfected individuals to strictly adhere to the recommended truvada dosing schedule. the effectiveness of truvada in reducing the risk of acquiring hiv-1 is strongly correlated with adherence as demonstrated by measurable drug levels in clinical trials [see clinical studies (14.2 and 14.3)].

the truvada dose adjusted accordingly. table 1 dosing for pediatric patients weighing 17 kg to less than 35 kg using truvada low-strength tablets body weight (kg) dosing of ftc (mg)/tdf (mg) 17 to less than 22 one 100/150 tablet once daily 22 to less than 28 one 133/200 tablet once daily 28 to less than 35 one 167/250 tablet once daily 2.3 recommended dose for pre-exposure prophylaxis the dose of truvada in hiv-1 uninfected adults is one tablet (containing 200 mg of emtricitabine and 300 mg of tenofovir disoproxil fumarate) once daily taken orally with or without food. 2.4 dose adjustment for renal impairment treatment of hiv-1 infection significantly increased drug exposures occurred when emtriva or viread were administered to subjects with moderate to severe renal impairment [see emtriva or viread prescribing information]. therefore, adjust the dosing interval of truvada in hiv-1 infected adult patients with baseline creatinine clearance 30–49 ml/min using the recommendations in table 2. these dosing interval recommendations are based on modeling of single-dose pharmacokinetic data in non-hiv infected subjects. the safety and effectiveness of these dosing interval adjustment recommendations have not been clinically evaluated in patients with moderate renal impairment; therefore, clinical response to treatment and renal function should be closely monitored in these patients [see warnings and precautions (5.2)]. no dose adjustment is necessary for hiv-1 infected patients with mild renal impairment (creatinine clearance 50–80 ml/min). no data are available to make dose recommendations in pediatric patients with renal impairment. table 2 dosage adjustment for hiv-1 infected adult patients with altered creatinine clearance creatinine clearance (ml/min)* ≥50 30–49 <30 (including patients requiring hemodialysis) * calculated using ideal (lean) body weight recommended dosing interval every 24 hours every 48 hours truvada should not be administered. routine monitoring of estimated creatinine clearance, serum phosphorus, urine glucose, and urine protein should be performed in all individuals with mild renal impairment [see warnings and precautions (5.2)]. pre-exposure prophylaxis do not use truvada for a prep indication in hiv-1 uninfected individuals with estimated creatinine clearance below 60 ml/min [see warnings and precautions (5.2)]. routine monitoring of estimated creatinine clearance, serum phosphorus, urine glucose, and urine protein should be performed in all individuals with mild renal impairment. if a decrease in estimated creatinine clearance is observed in uninfected individuals while using truvada for prep, evaluate potential causes and re-assess potential risks and benefits of continued use [see warnings and precautions (5.2)].

-controlled clinical trial of efavirenz, emtricitabine, and tenofovir df, include diarrhea, nausea, fatigue, headache, dizziness, depression, insomnia, abnormal dreams, and rash. see also table 3 for the frequency of treatment-emergent adverse reactions (grades 2–4) occurring in greater than or equal to 5% of subjects treated in any treatment group in this trial. skin discoloration, manifested by hyperpigmentation on the palms and/or soles, was generally mild and asymptomatic. the mechanism and clinical significance are unknown. study 934 –treatment emergent adverse reactions: in study 934, 511 antiretroviral-naïve subjects received either viread + emtriva administered in combination with efavirenz (n=257) or zidovudine/lamivudine administered in combination with efavirenz (n=254) for 144 weeks. subjects had a mean age of 40 years (range 20 to 73 years) and were predominantly male (88%). overall, 65% were white, 17% were black, and 13% were hispanic. adverse reactions observed in this trial were generally consistent with those seen in other trials in treatment-experienced or treatment-naïve subjects receiving viread and/or emtriva (table 3). table 3 selected treatment-emergent adverse reactions* (grades 2–4) reported in ≥5% in any treatment group in study 934 (0–144 weeks) ftc+tdf+efv† azt/3tc+efv n=257 n=254 * frequencies of adverse reactions are based on all treatment-emergent adverse events, regardless of relationship to study drug. † from weeks 96 to 144 of the trial, subjects received truvada with efavirenz in place of viread + emtriva with efavirenz. ‡ rash event includes rash, exfoliative rash, rash generalized, rash macular, rash maculo-papular, rash pruritic, and rash vesicular. gastrointestinal disorder diarrhea 9% 5% nausea 9% 7% vomiting 2% 5% general disorders and administration site condition fatigue 9% 8% infections and infestations sinusitis 8% 4% upper respiratory tract infections 8% 5% nasopharyngitis 5% 3% nervous system disorders headache 6% 5% dizziness 8% 7% psychiatric disorders depression 9% 7% insomnia 5% 7% skin and subcutaneous tissue disorders rash event‡ 7% 9% in addition to the events described above for study 934, other adverse reactions that occurred in at least 5% of subjects receiving emtriva or viread with other antiretroviral agents in clinical trials include anxiety, arthralgia, increased cough, dyspepsia, fever, myalgia, pain, abdominal pain, back pain, paresthesia, peripheral neuropathy (including peripheral neuritis and neuropathy), pneumonia, and rhinitis. laboratory abnormalities: laboratory abnormalities observed in this trial were generally consistent with those seen in other trials of viread and/or emtriva (table 4). table 4 significant laboratory abnormalities reported in ≥1% of subjects in any treatment group in study 934 (0–144 weeks) ftc+tdf+efv* azt/3tc+efv n=257 n=254 * from weeks 96 to 144 of the trial, subjects received truvada with efavirenz in place of viread + emtriva with efavirenz. any ≥ grade 3 laboratory abnormality 30% 26% fasting cholesterol (>240 mg/dl) 22% 24% creatine kinase (m: >990 u/l) (f: >845 u/l) 9% 7% serum amylase (>175 u/l) 8% 4% alkaline phosphatase (>550 u/l) 1% 0% ast (m: >180 u/l) (f: >170 u/l) 3% 3% alt (m: >215 u/l) (f: >170 u/l) 2% 3% hemoglobin (<8.0 mg/dl) 0% 4% hyperglycemia (>250 mg/dl) 2% 1% hematuria (>75 rbc/hpf) 3% 2% glycosuria (≥3+) <1% 1% neutrophils (<750/mm3) 3% 5% fasting triglycerides (>750 mg/dl) 4% 2% in addition to the laboratory abnormalities described above for study 934, grades 3−4 laboratory abnormalities of increased bilirubin (>2.5 × uln), increased pancreatic amylase (>2.0 × uln), increased or decreased serum glucose (<40 or >250 mg/dl), and increased serum lipase (>2.0 × uln) occurred in up to 3% of subjects treated with emtriva or viread with other antiretroviral agents in clinical trials. clinical trials in pediatric subjects emtricitabine: in addition to the adverse reactions reported in adults, anemia and hyperpigmentation were observed in 7% and 32%, respectively, of pediatric subjects (3 months to less than 18 years of age) who received treatment with emtriva in the larger of two open-label, uncontrolled pediatric trials (n=116). for additional information, consult the emtriva prescribing information. tenofovir df: in pediatric clinical trials (studies 352 and 321) conducted in 184 hiv-1 infected subjects 2 to less than 18 years of age, the adverse reactions observed in pediatric subjects who received treatment with viread were consistent with those observed in clinical trials of viread in adults. eighty-nine pediatric subjects (2 to less than 12 years of age) received viread in study 352 for a median exposure of 104 weeks. of these, 4 subjects discontinued from the trial due to adverse reactions consistent with proximal renal tubulopathy. three of these 4 subjects presented with hypophosphatemia and also had decreases in total body or spine bmd z score [see warnings and precautions (5.5)]. for additional information, consult the viread prescribing information. 6.2 adverse reactions from clinical trial experience in hiv-1 uninfected adult subjects no new adverse reactions to truvada were identified from two randomized placebo-controlled clinical trials (iprex, partners prep), in which 2,830 hiv-1 uninfected adults received truvada once daily for pre-exposure prophylaxis. subjects were followed for a median of 71 weeks and 87 weeks, respectively. these trials enrolled hiv-negative individuals ranging in age from 18 to 67 years. the iprex trial enrolled only men or transgender women of hispanic/latino (72%), white (18%), black (9%), and asian (5%) race. the partners prep trial enrolled both men (61−64% across treatment groups) and women in kenya and uganda. table 5 provides a list of all adverse events that occurred in 2% or more of subjects in any treatment group in the iprex and partners prep trials. laboratory abnormalities: table 6 provides a list of laboratory abnormalities observed in both trials. six subjects in the tdf-containing arms of the partners prep trial discontinued participation in the study due to an increase in blood creatinine compared with no discontinuations in the placebo group. one subject in the truvada arm of the iprex trial discontinued from the study due to an increase in blood creatinine and another due to low phosphorous. in addition to the laboratory abnormalities described above, grade 1 proteinuria (1+) occurred in 6% of subjects receiving truvada in the iprex trial. grades 2−3 proteinuria (2–4+) and glycosuria (3+) occurred in less than 1% of subjects treated with truvada in the iprex trial and partners prep trial. table 5 selected adverse events (all grades) reported in ≥2% in any treatment group in the iprex trial and partners prep trial iprex trial partners prep trial ftc/tdf (n=1251) placebo (n=1248) ftc/tdf (n=1579) placebo (n=1584) * not reported or reported below 2%. gastrointestinal disorders diarrhea 7% 8% 2% 3% abdominal pain 4% 2% -* - infections and infestations pharyngitis 13% 16% - - urethritis 5% 7% - - urinary tract infection 2% 2% 5% 7% syphilis 6% 5% - - secondary syphilis 6% 4% - - anogenital warts 2% 3% - - musculoskeletal and connective tissue disorders back pain 5% 5% - - nervous system disorders headache 7% 6% - - psychiatric disorders depression 6% 7% - - anxiety 3% 3% - - reproductive system and breast disorders genital ulceration 2% 2% 2% 2% investigations weight decreased 3% 2% - - table 6 laboratory abnormalities (highest toxicity grade) reported for each subject in the iprex trial and partners prep trial iprex trial partners prep trial grade* ftc/tdf (n=1251) placebo (n=1248) ftc/tdf (n=1579) placebo (n=1584) * grading is per daids criteria. † grade 1 phosphorus was not reported for the partners prep trial. creatinine 1 (1.1 – 1.3 × uln) 27 (2%) 21 (2%) 18 (1%) 12 (<1%) 2–4 (>1.4 × uln) 5 (<1%) 3 (<1%) 2 (<1%) 1 (<1%) phosphorus 1 (2.5 – 2.6 × uln) 57 (5%) 61 (5%) 10 (<1%) 4 (<1%) alt 1 (1.25 – <2.5 × uln) 178 (14%) 194 (16%) 21 (1%) 13 (<1%) 2–4 (>2.6 × uln) 84 (7%) 82 (7%) 4 (<1%) 6 (<1%) hemoglobin 1 (8.5–10 mg/dl) 49 (4%) 62 (5%) 56 (4%) 39 (2%) 2–4 (<9.4 mg/dl) 13 (1%) 19 (2%) 28 (2%) 39 (2%) neutrophils 1 (1000 – 1300/mm3) 23 (2%) 25 (2%) 208 (13%) 163 (10%) 2–4 (<750/mm3) 7 (<1%) 7 (<1%) 73 (5%) 56 (3%) changes in bone mineral density in clinical trials of hiv-1 uninfected individuals, decreases in bmd were observed. in the iprex trial, a substudy of 503 subjects found mean changes from baseline in bmd ranging from –0.4% to –1.0% across total hip, spine, femoral neck, and trochanter in the truvada group compared with the placebo group, which returned toward baseline after discontinuation of treatment. thirteen percent of subjects receiving truvada versus 6% of subjects receiving placebo lost at least 5% of bmd at the spine during treatment. bone fractures were reported in 1.7% of the truvada group compared with 1.4% in the placebo group. no correlation between bmd and fractures was noted [see clinical studies (14.2)]. the partners prep trial found similar fracture rates between treatment and placebo groups (0.8% and 0.6%, respectively); no bmd evaluations were performed during this trial [see clinical studies (14.3)]. 6.3 postmarketing experience the following adverse reactions have been identified during postapproval use of viread. no additional adverse reactions have been identified during postapproval use of emtriva. because postmarketing reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. immune system disorders allergic reaction, including angioedema metabolism and nutrition disorders lactic acidosis, hypokalemia, hypophosphatemia respiratory, thoracic, and mediastinal disorders dyspnea gastrointestinal disorders pancreatitis, increased amylase, abdominal pain hepatobiliary disorders hepatic steatosis, hepatitis, increased liver enzymes (most commonly ast, alt gamma gt) skin and subcutaneous tissue disorders rash musculoskeletal and connective tissue disorders rhabdomyolysis, osteomalacia (manifested as bone pain and which may contribute to fractures), muscular weakness, myopathy renal and urinary disorders acute renal failure, renal failure, acute tubular necrosis, fanconi syndrome, proximal renal tubulopathy, interstitial nephritis (including acute cases), nephrogenic diabetes insipidus, renal insufficiency, increased creatinine, proteinuria, polyuria general disorders and administration site conditions asthenia the following adverse reactions, listed under the body system headings above, may occur as a consequence of proximal renal tubulopathy: rhabdomyolysis, osteomalacia, hypokalemia, muscular weakness, myopathy, hypophosphatemia.

been observed in patients receiving tenofovir df with didanosine 400 mg daily. in patients weighing greater than 60 kg, the didanosine dose should be reduced to 250 mg when it is coadministered with truvada. data are not available to recommend a dose adjustment of didanosine for adult or pediatric patients weighing less than 60 kg. when coadministered, truvada and videx ec may be taken under fasted conditions or with a light meal (less than 400 kcal, 20% fat). 7.2 hiv-1 protease inhibitors tenofovir decreases the auc and cmin of atazanavir [see clinical pharmacology (12.3)]. when coadministered with truvada, it is recommended that atazanavir 300 mg is given with ritonavir 100 mg. truvada should not be coadministered with atazanavir without ritonavir. lopinavir/ritonavir, atazanavir coadministered with ritonavir, and darunavir coadministered with ritonavir have been shown to increase tenofovir concentrations [see clinical pharmacology (12.3)]. tenofovir df is a substrate of p-glycoprotein (p-gp) and breast cancer resistance protein (bcrp) transporters. when tenofovir df is coadministered with an inhibitor of these transporters, an increase in absorption may be observed. patients receiving truvada concomitantly with lopinavir/ritonavir, ritonavir-boosted atazanavir, or ritonavir-boosted darunavir should be monitored for tenofovir df-associated adverse reactions. truvada should be discontinued in patients who develop tenofovir df-associated adverse reactions. 7.3 hepatitis c antiviral agents coadministration of truvada and epclusa® (sofosbuvir/velpatasvir) or harvoni®(ledipasvir/sofosbuvir has been shown to increase tenofovir exposure [see clinical pharmacology (12.3)]. in patients receiving truvada concomitantly with epclusa, monitor for adverse reactions associated with tenofovir df. in patients receiving truvada concomitantly with harvoni without an hiv-1 protease inhibitor/ritonavir or an hiv-1 protease inhibitor/cobicistat combination, monitor for adverse reactions associated with tenofovir df. in patients receiving truvada concomitantly with harvoni and an hiv-1 protease inhibitor/ritonavir or an hiv-1 protease inhibitor/cobicistat combination, consider an alternative hcv or antiretroviral therapy, as the safety of increased tenofovir concentrations in this setting has not been established. if coadministration is necessary, monitor for adverse reactions associated with tenofovir df. 7.4 drugs affecting renal function emtricitabine and tenofovir are primarily excreted by the kidneys by a combination of glomerular filtration and active tubular secretion [see clinical pharmacology (12.3)]. no drug-drug interactions due to competition for renal excretion have been observed; however, coadministration of truvada with drugs that are eliminated by active tubular secretion may increase concentrations of emtricitabine, tenofovir, and/or the coadministered drug. some examples include, but are not limited to, acyclovir, adefovir dipivoxil, cidofovir, ganciclovir, valacyclovir, valganciclovir, aminoglycosides (e.g., gentamicin), and high-dose or multiple nsaids [see warnings and precautions (5.2)]. drugs that decrease renal function may increase concentrations of emtricitabine and/or tenofovir.

v-1 infection during pregnancy. clinical considerations as of july 2011, the apr has received prospective reports of 764 and 1219 exposures to emtricitabine- and tenofovir-containing regimens, respectively, in the first trimester; 321 and 455 exposures, respectively, in second trimester; and 140 and 257 exposures, respectively, in the third trimester. birth defects occurred in 18 of 764 (2.4%) live births for emtricitabine-containing regimens and 27 of 1219 (2.2%) live births for tenofovir-containing regimens (first trimester exposure); and 10 of 461 (2.2%) live births for emtricitabine-containing regimens and 15 of 714 (2.1%) live births for tenofovir-containing regimens (second/third trimester exposure). among pregnant women in the u.s. reference population, the background rate of birth defects is 2.7%. there was no association between emtricitabine or tenofovir and overall birth defects observed in the apr. animal data emtricitabine the incidence of fetal variations and malformations was not increased in embryofetal toxicity studies performed with emtricitabine in mice at exposures (auc) approximately 60-fold higher and in rabbits at approximately 120-fold higher than human exposures at the recommended daily dose. tenofovir df reproduction studies have been performed in rats and rabbits at doses up to 14 and 19 times the human dose based on body surface area comparisons and revealed no evidence of impaired fertility or harm to the fetus due to tenofovir. 8.3 nursing mothers nursing mothers: the centers for disease control and prevention recommend that hiv-1 infected mothers not breastfeed their infants to avoid risking postnatal transmission of hiv-1. studies in humans have shown that both tenofovir and emtricitabine are excreted in human milk. because the risks of low-level exposure to emtricitabine and tenofovir to infants are unknown, mothers should be instructed not to breastfeed if they are receiving truvada, whether they are taking truvada for treatment or to reduce the risk of acquiring hiv-1. emtricitabine samples of breast milk obtained from five hiv-1 infected mothers show that emtricitabine is secreted in human milk. breastfeeding infants whose mothers are being treated with emtricitabine may be at risk for developing viral resistance to emtricitabine. other emtricitabine-associated risks in infants breastfed by mothers being treated with emtricitabine are unknown. tenofovir df samples of breast milk obtained from five hiv-1 infected mothers show that tenofovir is secreted in human milk. tenofovir-associated risks, including the risk of viral resistance to tenofovir, in infants breastfed by mothers being treated with tenofovir df are unknown. 8.4 pediatric use no pediatric clinical trial was conducted to evaluate the safety and efficacy of truvada. data from previously conducted trials with the individual drug products, emtriva and viread, were relied upon to support dosing recommendations for truvada. for additional information, consult the prescribing information for emtriva and viread. truvada should only be administered to hiv-1 infected pediatric patients with body weight greater than or equal to 17 kg and who are able to swallow a whole tablet. because it is a fixed-dose combination tablet, truvada cannot be adjusted for patients of lower weight [see warnings and precautions (5.5), adverse reactions (6.1) and clinical pharmacology (12.3)]. truvada has not been evaluated for use in pediatric patients weighing less than 17 kg. 8.5 geriatric use clinical trials of emtriva or viread did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. in general, dose selection for the elderly patients should be cautious, keeping in mind the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. 8.6 patients with impaired renal function treatment of hiv-1 infection the dosing interval for truvada should be modified in hiv-infected adult patients with estimated creatinine clearance of 30–49 ml/min. truvada should not be used in patients with estimated creatinine clearance below 30 ml/min and in patients with end-stage renal disease requiring dialysis [see dosage and administration (2.4)]. pre-exposure prophylaxis truvada for a prep indication should not be used in hiv-1 uninfected individuals with estimated creatinine clearance below 60 ml/min. if a decrease in estimated creatinine clearance is observed in uninfected individuals while using truvada for prep, evaluate potential causes and re-assess potential risks and benefits of continued use [see dosage and administration (2.4)].

is recovered in the urine and 13% is recovered as metabolites. the metabolites of emtricitabine include 3'-sulfoxide diastereomers and their glucuronic acid conjugate. emtricitabine is eliminated by a combination of glomerular filtration and active tubular secretion. following a single oral dose of emtriva, the plasma emtricitabine half-life is approximately 10 hours. tenofovir df: the pharmacokinetic properties of tenofovir df are summarized in table 7. following oral administration of viread, maximum tenofovir serum concentrations are achieved in 1.0 ± 0.4 hour. less than 0.7% of tenofovir binds to human plasma proteins in vitro, and the binding is independent of concentration over the range of 0.01–25 µg/ml. approximately 70–80% of the intravenous dose of tenofovir is recovered as unchanged drug in the urine. tenofovir is eliminated by a combination of glomerular filtration and active tubular secretion. following a single oral dose of viread, the terminal elimination half-life of tenofovir is approximately 17 hours. table 7 single dose pharmacokinetic parameters for emtricitabine and tenofovir in adults* emtricitabine tenofovir * nc=not calculated † median (range) ‡ mean (± sd) § data presented as steady state values fasted oral bioavailability† (%) 92 (83.1–106.4) 25 (nc–45.0) plasma terminal elimination half-life† (hr) 10 (7.4–18.0) 17 (12.0–25.7) cmax‡ (μg/ml) 1.8±0.72§ 0.30±0.09 auc‡ (μg∙hr/ml) 10.0±3.12§ 2.29±0.69 cl/f‡ (ml/min) 302±94 1043±115 clrenal‡ (ml/min) 213±89 243±33 effects of food on oral absorption truvada may be administered with or without food. administration of truvada following a high fat meal (784 kcal; 49 grams of fat) or a light meal (373 kcal; 8 grams of fat) delayed the time of tenofovir cmax by approximately 0.75 hour. the mean increases in tenofovir auc and cmax were approximately 35% and 15%, respectively, when administered with a high fat or light meal, compared to administration in the fasted state. in previous safety and efficacy trials, viread (tenofovir) was taken under fed conditions. emtricitabine systemic exposures (auc and cmax) were unaffected when truvada was administered with either a high fat or a light meal. specific populations race emtricitabine: no pharmacokinetic differences due to race have been identified following the administration of emtriva. tenofovir df: there were insufficient numbers from racial and ethnic groups other than caucasian to adequately determine potential pharmacokinetic differences among these populations following the administration of viread. gender emtricitabine and tenofovir df: emtricitabine and tenofovir pharmacokinetics are similar in male and female subjects. pediatric patients the pharmacokinetic data for tenofovir and emtricitabine following administration of truvada in pediatric subjects weighing 17 kg and above are not available. the dosing recommendations of truvada in this population are based on the dosing recommendations of emtriva and viread in this population. refer to the emtriva and viread prescribing information for pharmacokinetic information on the individual products in pediatric patients. truvada should not be administered to hiv-1 infected pediatric patients weighing less than 17 kg. geriatric patients pharmacokinetics of emtricitabine and tenofovir have not been fully evaluated in the elderly (65 years of age and older). patients with impaired renal function the pharmacokinetics of emtricitabine and tenofovir are altered in subjects with renal impairment [see warnings and precautions (5.2)]. in adult subjects with creatinine clearance below 50 ml/min, cmax, and auc0–∞ of emtricitabine and tenofovir were increased. it is recommended that the dosing interval for truvada be modified in hiv-infected adult patients with estimated creatinine clearance 30–49 ml/min. no data are available to make dose recommendations in pediatric patients with renal impairment. truvada should not be used in patients with estimated creatinine clearance below 30 ml/min and in patients with end-stage renal disease requiring dialysis [see dosage and administration (2.4)]. truvada for a prep indication should not be used in hiv-1 uninfected individuals with estimated creatinine clearance below 60 ml/min. if a decrease in estimated creatinine clearance is observed in uninfected individuals while using truvada for prep, evaluate potential causes and re-assess potential risks and benefits of continued use [see dosage and administration (2.4)]. patients with hepatic impairment the pharmacokinetics of tenofovir following a 300 mg dose of viread have been studied in non-hiv infected subjects with moderate to severe hepatic impairment. there were no substantial alterations in tenofovir pharmacokinetics in subjects with hepatic impairment compared with unimpaired subjects. the pharmacokinetics of truvada or emtricitabine have not been studied in subjects with hepatic impairment; however, emtricitabine is not significantly metabolized by liver enzymes, so the impact of liver impairment should be limited. assessment of drug interactions the steady state pharmacokinetics of emtricitabine and tenofovir were unaffected when emtricitabine and tenofovir df were administered together versus each agent dosed alone. in vitro studies and clinical pharmacokinetic drug-drug interaction trials have shown that the potential for cyp mediated interactions involving emtricitabine and tenofovir with other medicinal products is low. no clinically significant drug interactions have been observed between emtricitabine and famciclovir, indinavir, stavudine, tenofovir df, and zidovudine (tables 8 and 9). similarly, no clinically significant drug interactions have been observed between tenofovir df and efavirenz, methadone, nelfinavir, oral contraceptives, ribavirin, or sofosbuvir in trials conducted in healthy volunteers (tables 10 and 11). table 8 drug interactions: changes in pharmacokinetic parameters for emtricitabine in the presence of the coadministered drug* coadministered drug dose of coadministered drug (mg) emtricitabine dose (mg) n % change of emtricitabine pharmacokinetic parameters† (90% ci) cmax auc cmin * all interaction trials conducted in healthy volunteers † ↑ = increase; ⇔ = no effect; na = not applicable tenofovir df 300 once daily × 7 days 200 once daily × 7 days 17 ⇔ ⇔ ↑ 20 (↑ 12 to ↑ 29) zidovudine 300 twice daily × 7 days 200 once daily × 7 days 27 ⇔ ⇔ ⇔ indinavir 800 × 1 200 × 1 12 ⇔ ⇔ na famciclovir 500 × 1 200 × 1 12 ⇔ ⇔ na stavudine 40 × 1 200 × 1 6 ⇔ ⇔ na table 9 drug interactions: changes in pharmacokinetic parameters for coadministered drug in the presence of emtricitabine* coadministered drug dose of coadministered drug (mg) emtricitabine dose (mg) n % change of coadministered drug pharmacokinetic parameters† (90% ci) cmax auc cmin * all interaction trials conducted in healthy volunteers † ↑ = increase; ⇔ = no effect; na = not applicable tenofovir df 300 once daily × 7 days 200 once daily × 7 days 17 ⇔ ⇔ ⇔ zidovudine 300 twice daily × 7 days 200 once daily × 7 days 27 ↑ 17 (↑ 0 to ↑ 38) ↑ 13 (↑ 5 to ↑ 20) ⇔ indinavir 800 × 1 200 × 1 12 ⇔ ⇔ na famciclovir 500 × 1 200 × 1 12 ⇔ ⇔ na stavudine 40 × 1 200 × 1 6 ⇔ ⇔ na table 10 drug interactions: changes in pharmacokinetic parameters for tenofovir*in the presence of the coadministered drug coadministered drug dose of coadministered drug (mg) n % change of tenofovir pharmacokinetic parameters† (90% ci) cmax auc cmin * subjects received viread 300 mg once daily. † increase = ↑; decrease = ↓; no effect = ⇔ ‡ reyataz prescribing information. § prezista prescribing information. ¶ data generated from simultaneous dosing with harvoni (ledipasvir/sofosbuvir). staggered administration (12 hours apart) provided similar results. # comparison based on exposures when administered as atazanavir/ritonavir + emtricitabine/tenofovir df. Þ comparison based on exposures when administered as darunavir/ritonavir + emtricitabine/tenofovir df. s study conducted with atripla (efavirenz/emtricitabine/tenofovir df) coadministered with harvoni. À study conducted with complera (emtricitabine/rilpivirine/tenofovir df) coadministered with harvoni. È study conducted with truvada (emtricitabine/tenofovir df) + dolutegravir coadministered with harvoni. Ð study conducted with atripla coadministered with sovaldi ® (sofosbuvir). Ø comparison based on exposures when administered as atazanavir/ritonavir + emtricitabine/tenofovir df. Ý comparison based on exposures when administered as darunavir/ritonavir + emtricitabine/tenofovir df. £ study conducted with atripla coadministered with epclusa (sofosbuvir/velpatasvir). ¥ study conducted with stribild (elvitegravir/cobicistat/emtricitabine/tenofovir df) coadministered with epclusa. Œ study conducted with complera coadministered with epclusa. Œ administered as raltegravir + emtricitabine/tenofovir df. Ɖ aptivus prescribing information. atazanavir‡ 400 once daily × 14 days 33 ↑ 14 (↑ 8 to ↑ 20) ↑ 24 (↑ 21 to ↑ 28) ↑ 22 (↑ 15 to ↑ 30) atazanavir/ ritonavir‡ 300/100 once daily 12 ↑ 34 (↑ 20 to ↑ 51) ↑ 37 (↑ 30 to ↑ 45) ↑ 29 (↑ 21 to ↑ 36) darunavir/ ritonavir§ 300/100 twice daily 12 ↑ 24 (↑ 8 to ↑ 42) ↑ 22 (↑ 10 to ↑ 35) ↑ 37 (↑ 19 to ↑ 57) indinavir 800 three times daily × 7 days 13 ↑ 14 (↓ 3 to ↑ 33) ⇔ ⇔ ledipasvir/ sofosbuvir¶,# 90/400 once daily × 10 days 24 ↑ 47 (↑ 37 to ↑ 58) ↑ 35 (↑ 29 to ↑42 ) ↑ 47 (↑ 38 to ↑ 57) ledipasvir/ sofosbuvir¶,Þ 23 ↑ 64 (↑ 54 to ↑ 74) ↑ 50 (↑ 42 to ↑ 59) ↑ 59 (↑ 49 to ↑ 70) ledipasvir/ sofosbuvirs 90/400 once daily × 14 days 15 ↑ 79 (↑ 56 to ↑ 104) ↑ 98 (↑ 77 to ↑ 123) ↑ 163 (↑ 132 to ↑ 197) ledipasvir/ sofosbuvirÀ 90/400 once daily × 10 days 14 ↑ 32 (↑ 25 to ↑ 39 ) ↑ 40 (↑ 31 to ↑ 50 ) ↑ 91 (↑ 74 to ↑ 110) ledipasvir/ sofosbuvirÈ 90/400 once daily × 10 days 29 ↑ 61 (↑ 51 to ↑ 72) ↑ 65 (↑ 59 to ↑ 71) ↑ 115 (↑ 105 to ↑ 126) lopinavir/ ritonavir 400/100 twice daily × 14 days 24 ⇔ ↑ 32 (↑ 25 to ↑ 38) ↑ 51 (↑ 37 to ↑ 66) saquinavir/ ritonavir 1000/100 twice daily × 14 days 35 ⇔ ⇔ ↑ 23 (↑ 16 to ↑ 30) sofosbuvirÐ 400 single dose 16 ↑ 25 (↑ 8 to ↑ 45) ⇔ ⇔ sofosbuvir/ velpatasvirØ 400/100 once daily 24 ↑ 55 (↑ 43 to ↑ 68) ↑ 30 (↑ 24 to ↑ 36) ↑ 39 (↑ 31 to ↑ 48) sofosbuvir/ velpatasvirÝ 400/100 once daily 29 ↑ 55 (↑ 45 to ↑ 66) ↑ 39 (↑ 33 to ↑ 44) ↑ 52 (↑ 45 to ↑ 59) sofosbuvir/ velpatasvir£ 400/100 once daily 15 ↑ 77 (↑ 53 to ↑ 104) ↑ 81 (↑ 68 to ↑ 94) ↑ 121 (↑ 100 to ↑ 143) sofosbuvir/ velpatasvir¥ 400/100 once daily 24 ↑ 36 (↑ 25 to ↑ 47) ↑ 35 (↑ 29 to ↑ 42) ↑ 45 (↑ 39 to ↑ 51) sofosbuvir/ velpatasvirŒ 400/100 once daily 24 ↑ 44 (↑ 33 to ↑ 55) ↑ 40 (↑ 34 to ↑ 46) ↑ 84 (↑ 76 to ↑ 92) sofosbuvir/ velpatasvirŒ 400/100 once daily 30 ↑ 46 (↑ 39 to ↑ 54) ↑ 40 (↑ 34 to ↑ 45) ↑ 70 (↑ 61 to ↑ 79) tacrolimus 0.05 mg/kg twice daily × 7 days 21 ↑ 13 (↑ 1 to ↑ 27) ⇔ ⇔ tipranavir/ritonavirƉ 500/100 twice daily 22 ↓ 23 (↓ 32 to ↓ 13) ↓ 2 (↓ 9 to ↑ 5) ↑ 7 (↓ 2 to ↑ 17) 750/200 twice daily (23 doses) 20 ↓ 38 (↓ 46 to ↓ 29) ↑ 2 (↓ 6 to ↑ 10) ↑ 14 (↑ 1 to ↑ 27) no effect on the pharmacokinetic parameters of the following coadministered drugs was observed with truvada: abacavir, didanosine (buffered tablets), emtricitabine, entecavir, and lamivudine. table 11 drug interactions: changes in pharmacokinetic parameters for coadministered drug in the presence of tenofovir coadministered drug dose of coadministered drug (mg) n % change of coadministered drug pharmacokinetic parameters* (90% ci) cmax auc cmin * increase = ↑; decrease = ↓; no effect = ⇔; na = not applicable † reyataz prescribing information. ‡ in hiv-infected subjects, addition of tenofovir df to atazanavir 300 mg plus ritonavir 100 mg resulted in auc and c min values of atazanavir that were 2.3- and 4-fold higher than the respective values observed for atazanavir 400 mg when given alone. § prezista prescribing information. ¶ videx ec prescribing information. subjects received didanosine enteric-coated capsules. # 373 kcal, 8.2 g fat Þ compared with didanosine (enteric-coated) 400 mg administered alone under fasting conditions. s increases in auc and c min are not expected to be clinically relevant; hence, no dose adjustments are required when tenofovir df and ritonavir-boosted saquinavir are coadministered. À aptivus prescribing information. abacavir 300 once 8 ↑ 12 (↓ 1 to ↑ 26) ⇔ na atazanavir† 400 once daily × 14 days 34 ↓ 21 (↓ 27 to ↓ 14) ↓ 25 (↓ 30 to ↓ 19) ↓ 40 (↓ 48 to ↓ 32) atazanavir† atazanavir/ritonavir 300/100 once daily × 42 days 10 ↓ 28 (↓ 50 to ↑ 5) ↓ 25‡ (↓ 42 to ↓ 3) ↓ 23‡ (↓ 46 to ↑ 10) darunavir§ darunavir/ritonavir 300/100 once daily 12 ↑ 16 (↓ 6 to ↑ 42) ↑ 21 (↓ 5 to ↑ 54) ↑ 24 (↓ 10 to ↑ 69) didanosine¶ 250 once, simultaneously with tenofovir df and a light meal# 33 ↓ 20Þ (↓ 32 to ↓ 7) ⇔Þ na emtricitabine 200 once daily × 7 days 17 ⇔ ⇔ ↑ 20 (↑ 12 to ↑ 29) indinavir 800 three times daily × 7 days 12 ↓ 11 (↓ 30 to ↑ 12) ⇔ ⇔ entecavir 1 once daily × 10 days 28 ⇔ ↑ 13 (↑ 11 to ↑ 15) ⇔ lamivudine 150 twice daily × 7 days 15 ↓ 24 (↓ 34 to ↓ 12) ⇔ ⇔ lopinavir lopinavir/ritonavir 400/100 twice daily × 14 days 24 ⇔ ⇔ ⇔ ritonavir ⇔ ⇔ ⇔ saquinavir saquinavir/ritonavir 1000/100 twice daily × 14 days 32 ↑ 22 (↑ 6 to ↑41) ↑ 29s (↑ 12 to ↑ 48) ↑ 47s (↑ 23 to ↑ 76) ritonavir ⇔ ⇔ ↑ 23 (↑ 3 to ↑ 46) tacrolimus 0.05 mg/kg twice daily × 7 days 21 ⇔ ⇔ ⇔ tipranavirÀ tipranavir/ritonavir 500/100 twice daily 22 ↓ 17 (↓ 26 to ↓ 6) ↓ 18 (↓ 25 to ↓ 9) ↓ 21 (↓ 30 to ↓ 10) tipranavir/ritonavir 750/200 twice daily (23 doses) 20 ↓ 11 (↓ 16 to ↓ 4) ↓ 9 (↓ 15 to ↓ 3) ↓ 12 (↓ 22 to 0) coadministration of tenofovir df with didanosine results in changes in the pharmacokinetics of didanosine that may be of clinical significance. concomitant dosing of tenofovir df with didanosine enteric-coated capsules significantly increases the cmax and auc of didanosine. when didanosine 250 mg enteric-coated capsules were administered with tenofovir df, systemic exposures of didanosine were similar to those seen with the 400 mg enteric-coated capsules alone under fasted conditions. the mechanism of this interaction is unknown. see drug interactions (7.1) regarding use of didanosine with viread. 12.4 microbiology mechanism of action emtricitabine: emtricitabine, a synthetic nucleoside analog of cytidine, is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate. emtricitabine 5'-triphosphate inhibits the activity of the hiv-1 reverse transcriptase (rt) by competing with the natural substrate deoxycytidine 5'-triphosphate and by being incorporated into nascent viral dna which results in chain termination. emtricitabine 5'-triphosphate is a weak inhibitor of mammalian dna polymerases α, β, ε and mitochondrial dna polymerase γ. tenofovir df: tenofovir df is an acyclic nucleoside phosphonate diester analog of adenosine monophosphate. tenofovir df requires initial diester hydrolysis for conversion to tenofovir and subsequent phosphorylations by cellular enzymes to form tenofovir diphosphate. tenofovir diphosphate inhibits the activity of hiv-1 rt by competing with the natural substrate deoxyadenosine 5'-triphosphate and, after incorporation into dna, by dna chain termination. tenofovir diphosphate is a weak inhibitor of mammalian dna polymerases α, β and mitochondrial dna polymerase γ. antiviral activity emtricitabine and tenofovir df: no antagonism was observed in combination studies evaluating the cell culture antiviral activity of emtricitabine and tenofovir together. emtricitabine: the antiviral activity of emtricitabine against laboratory and clinical isolates of hiv-1 was assessed in lymphoblastoid cell lines, the magi-ccr5 cell line, and peripheral blood mononuclear cells. the 50% effective concentration (ec50) values for emtricitabine were in the range of 0.0013–0.64 µm (0.0003–0.158 µg/ml). in drug combination studies of emtricitabine with nucleoside reverse transcriptase inhibitors (abacavir, lamivudine, stavudine, zidovudine), non-nucleoside reverse transcriptase inhibitors (delavirdine, efavirenz, nevirapine), and protease inhibitors (amprenavir, nelfinavir, ritonavir, saquinavir), no antagonism was observed. emtricitabine displayed antiviral activity in cell culture against hiv-1 clades a, b, c, d, e, f, and g (ec50 values ranged from 0.007–0.075 µm) and showed strain-specific activity against hiv-2 (ec50 values ranged from 0.007–1.5 µm). tenofovir df: the antiviral activity of tenofovir against laboratory and clinical isolates of hiv-1 was assessed in lymphoblastoid cell lines, primary monocyte/macrophage cells, and peripheral blood lymphocytes. the ec50 values for tenofovir were in the range of 0.04–8.5 µm. in drug combination studies of tenofovir with nucleoside reverse transcriptase inhibitors (abacavir, didanosine, lamivudine, stavudine, zidovudine), non-nucleoside reverse transcriptase inhibitors (delavirdine, efavirenz, nevirapine), and protease inhibitors (amprenavir, indinavir, nelfinavir, ritonavir, saquinavir), no antagonism was observed. tenofovir displayed antiviral activity in cell culture against hiv-1 clades a, b, c, d, e, f, g, and o (ec50 values ranged from 0.5–2.2 µm) and showed strain-specific activity against hiv-2 (ec50 values ranged from 1.6 µm to 5.5 µm). prophylactic activity in a nonhuman primate model of hiv transmission emtricitabine and tenofovir df: the prophylactic activity of the combination of daily oral emtricitabine (ftc) and tenofovir disoproxil fumarate (tdf) was evaluated in a controlled study of macaques inoculated once weekly for 14 weeks with siv/hiv-1 chimeric virus (shiv) applied to the rectal surface. of the 18 control animals, 17 became infected after a median of 2 weeks. in contrast, 4 of the 6 animals treated daily with oral ftc and tdf remained uninfected and the two infections that did occur were significantly delayed until 9 and 12 weeks and exhibited reduced viremia. an m184i-expressing ftc-resistant variant emerged in 1 of the 2 macaques after 3 weeks of continued drug exposure. resistance emtricitabine and tenofovir df: hiv-1 isolates with reduced susceptibility to the combination of emtricitabine and tenofovir have been selected in cell culture. genotypic analysis of these isolates identified the m184v/i and/or k65r amino acid substitutions in the viral rt. in addition, a k70e substitution in hiv-1 reverse transcriptase has been selected by tenofovir and results in reduced susceptibility to tenofovir. in a clinical trial of treatment-naïve subjects [study 934, see clinical studies (14.1)], resistance analysis was performed on hiv-1 isolates from all confirmed virologic failure subjects with greater than 400 copies/ml of hiv-1 rna at week 144 or early discontinuation. development of efavirenz resistance-associated substitutions occurred most frequently and was similar between the treatment arms. the m184v amino acid substitution, associated with resistance to emtriva and lamivudine, was observed in 2/19 analyzed subject isolates in the emtriva + viread group and in 10/29 analyzed subject isolates in the zidovudine/lamivudine group. through 144 weeks of study 934, no subjects have developed a detectable k65r or k70e substitution in their hiv-1 as analyzed through standard genotypic analysis. emtricitabine: emtricitabine-resistant isolates of hiv-1 have been selected in cell culture and in vivo. genotypic analysis of these isolates showed that the reduced susceptibility to emtricitabine was associated with a substitution in the hiv-1 rt gene at codon 184 which resulted in an amino acid substitution of methionine by valine or isoleucine (m184v/i). tenofovir df: hiv-1 isolates with reduced susceptibility to tenofovir have been selected in cell culture. these viruses expressed a k65r substitution in rt and showed a 2–4 fold reduction in susceptibility to tenofovir. in treatment-naïve subjects, isolates from 8/47 (17%) analyzed subjects developed the k65r substitution in the viread arm through 144 weeks; 7 occurred in the first 48 weeks of treatment and 1 at week 96. in treatment-experienced subjects, 14/304 (5%) isolates from subjects failing viread through week 96 showed greater than 1.4-fold (median 2.7) reduced susceptibility to tenofovir. genotypic analysis of the resistant isolates showed a k65r amino acid substitution in the hiv-1 rt. iprex trial: in a clinical study of hiv-1 seronegative subjects [iprex trial, see clinical studies (14.2)], no amino acid substitutions associated with resistance to emtricitabine or tenofovir were detected at the time of seroconversion among 48 subjects in the truvada group and 83 subjects in the placebo group who became infected with hiv-1 during the trial. ten subjects were observed to be hiv-1 infected at time of enrollment. the m184v/i substitutions associated with resistance to emtricitabine were observed in 3 of the 10 subjects (2 of 2 in the truvada group and 1 of 8 in the placebo group). one of the two subjects in the truvada group harbored wild type virus at enrollment and developed the m184v substitution 4 weeks after enrollment. the other subject had indeterminate resistance at enrollment but was found to have the m184i substitution 4 weeks after enrollment. partners prep trial: in a clinical study of hiv-1 seronegative subjects [partners prep trial, see clinical studies (14.3)], no variants expressing amino acid substitutions associated with resistance to emtricitabine or tenofovir were detected at the time of seroconversion among 12 subjects in the truvada group, 15 subjects in the viread group, and 51 subjects in the placebo group. fourteen subjects were observed to be hiv-1 infected at the time of enrollment (3 in the truvada group, 5 in the viread group, and 6 in the placebo group). one of the three subjects in the truvada group who was infected with wild type virus at enrollment selected an m184v expressing virus by week 12. two of the five subjects in the viread group had tenofovir-resistant viruses at the time of seroconversion; one subject infected with wild type virus at enrollment developed a k65r substitution by week 16, while the second subject had virus expressing the combination of d67n and k70r substitutions upon seroconversion at week 60, although baseline virus was not genotyped and it is unclear if the resistance emerged or was transmitted. following enrollment, 4 subjects (2 in the viread group, 1 in the truvada group, and 1 in the placebo group) had virus expressing k103n or v106a substitutions, which confer high-level resistance to nnrtis but have not been associated with tenofovir or emtricitabine and may have been present in the infecting virus. cross resistance emtricitabine and tenofovir df: cross-resistance among certain nrtis has been recognized. the m184v/i and/or k65r substitutions selected in cell culture by the combination of emtricitabine and tenofovir are also observed in some hiv-1 isolates from subjects failing treatment with tenofovir in combination with either emtricitabine or lamivudine, and either abacavir or didanosine. therefore, cross-resistance among these drugs may occur in patients whose virus harbors either or both of these amino acid substitutions. emtricitabine: emtricitabine-resistant isolates (m184v/i) were cross-resistant to lamivudine but retained susceptibility in cell culture to the nrtis didanosine, stavudine, tenofovir, and zidovudine, and to nnrtis (delavirdine, efavirenz, and nevirapine). hiv-1 isolates containing the k65r substitution, selected in vivo by abacavir, didanosine, and tenofovir, demonstrated reduced susceptibility to inhibition by emtricitabine. viruses harboring substitutions conferring reduced susceptibility to stavudine and zidovudine (m41l, d67n, k70r, l210w, t215y/f, k219q/e), or didanosine (l74v) remained sensitive to emtricitabine. hiv-1 containing the k103n substitution associated with resistance to nnrtis was susceptible to emtricitabine. tenofovir df: the k65r and k70e substitutions selected by tenofovir are also selected in some hiv-1 infected patients treated with abacavir or didanosine. hiv-1 isolates with the k65r and k70e substitutions also showed reduced susceptibility to emtricitabine and lamivudine. therefore, cross-resistance among these nrtis may occur in patients whose virus harbors the k65r or k70e substitutions. hiv-1 isolates from subjects (n=20) whose hiv-1 expressed a mean of 3 zidovudine-associated rt amino acid substitutions (m41l, d67n, k70r, l210w, t215y/f, or k219q/e/n) showed a 3.1-fold decrease in the susceptibility to tenofovir. subjects whose virus expressed an l74v substitution without zidovudine resistance-associated substitutions (n=8) had reduced response to viread. limited data are available for patients whose virus expressed a y115f substitution (n=3), q151m substitution (n=2), or t69 insertion (n=4), all of whom had a reduced response.

dose. tenofovir df: long-term oral carcinogenicity studies of tenofovir df in mice and rats were carried out at exposures up to approximately 16 times (mice) and 5 times (rats) those observed in humans at the therapeutic dose for hiv-1 infection. at the high dose in female mice, liver adenomas were increased at exposures 16 times that in humans. in rats, the study was negative for carcinogenic findings at exposures up to 5 times that observed in humans at the therapeutic dose. tenofovir df was mutagenic in the in vitro mouse lymphoma assay and negative in an in vitro bacterial mutagenicity test (ames test). in an in vivo mouse micronucleus assay, tenofovir df was negative when administered to male mice. there were no effects on fertility, mating performance, or early embryonic development when tenofovir df was administered to male rats at a dose equivalent to 10 times the human dose based on body surface area comparisons for 28 days prior to mating and to female rats for 15 days prior to mating through day 7 of gestation. there was, however, an alteration of the estrous cycle in female rats. 13.2 animal toxicology and/or pharmacology tenofovir and tenofovir df administered in toxicology studies to rats, dogs, and monkeys at exposures (based on aucs) greater than or equal to 6-fold those observed in humans caused bone toxicity. in monkeys the bone toxicity was diagnosed as osteomalacia. osteomalacia observed in monkeys appeared to be reversible upon dose reduction or discontinuation of tenofovir. in rats and dogs, the bone toxicity manifested as reduced bone mineral density. the mechanism(s) underlying bone toxicity is unknown. evidence of renal toxicity was noted in four animal species. increases in serum creatinine, bun, glycosuria, proteinuria, phosphaturia, and/or calciuria and decreases in serum phosphate were observed to varying degrees in these animals. these toxicities were noted at exposures (based on aucs) 2–20 times higher than those observed in humans. the relationship of the renal abnormalities, particularly the phosphaturia, to the bone toxicity is not known.

viral-naïve subjects. from weeks 96 to 144 of the trial, subjects received truvada with efavirenz in place of emtricitabine + tenofovir df with efavirenz. subjects had a mean age of 38 years (range 18–80); 86% were male, 59% were caucasian, and 23% were black. the mean baseline cd4+ cell count was 245 cells/mm3 (range 2–1191) and median baseline plasma hiv-1 rna was 5.01 log10copies/ml (range 3.56–6.54). subjects were stratified by baseline cd4+ cell count (< or ≥200 cells/mm3); 41% had cd4+ cell counts <200 cells/mm3 and 51% of subjects had baseline viral loads >100,000 copies/ml. treatment outcomes through 48 and 144 weeks for those subjects who did not have efavirenz resistance at baseline are presented in table 12. table 12 outcomes of randomized treatment at week 48 and 144 (study 934) outcomes at week 48 at week 144 ftc+tdf +efv (n=244) azt/3tc+efv (n=243) ftc+tdf+efv (n=227)* azt/3tc+efv (n=229)* * subjects who were responders at week 48 or week 96 (hiv-1 rna <400 copies/ml) but did not consent to continue trial after week 48 or week 96 were excluded from analysis. † subjects achieved and maintained confirmed hiv-1 rna <400 copies/ml through weeks 48 and 144. ‡ includes confirmed viral rebound and failure to achieve confirmed <400 copies/ml through weeks 48 and 144. § includes lost to follow-up, subject withdrawal, noncompliance, protocol violation, and other reasons. responder† 84% 73% 71% 58% virologic failure‡ 2% 4% 3% 6% rebound 1% 3% 2% 5% never suppressed 0% 0% 0% 0% change in antiretroviral regimen 1% 1% 1% 1% death <1% 1% 1% 1% discontinued due to adverse event 4% 9% 5% 12% discontinued for other reasons§ 10% 14% 20% 22% through week 48, 84% and 73% of subjects in the emtricitabine + tenofovir df group and the zidovudine/lamivudine group, respectively, achieved and maintained hiv-1 rna <400 copies/ml (71% and 58% through week 144). the difference in the proportion of subjects who achieved and maintained hiv-1 rna <400 copies/ml through 48 weeks largely results from the higher number of discontinuations due to adverse events and other reasons in the zidovudine/lamivudine group in this open-label trial. in addition, 80% and 70% of subjects in the emtricitabine + tenofovir df group and the zidovudine/lamivudine group, respectively, achieved and maintained hiv-1 rna <50 copies/ml through week 48 (64% and 56% through week 144). the mean increase from baseline in cd4+ cell count was 190 cells/mm3 in the emtricitabine + tenofovir df group and 158 cells/mm3 in the zidovudine/lamivudine group at week 48 (312 and 271 cells/mm3 at week 144). through 48 weeks, 7 subjects in the emtricitabine + tenofovir df group and 5 subjects in the zidovudine/lamivudine group experienced a new cdc class c event (10 and 6 subjects through 144 weeks). 14.2 iprex trial the iprex trial was a randomized, double-blind, placebo-controlled multinational study evaluating truvada in 2,499 hiv-seronegative men or transgender women who have sex with men and with evidence of high-risk behavior for hiv-1 infection. evidence of high-risk behavior included any one of the following reported to have occurred up to six months prior to study screening: no condom use during anal intercourse with an hiv-1 positive partner or a partner of unknown hiv status; anal intercourse with more than 3 sex partners; exchange of money, gifts, shelter, or drugs for anal sex; sex with male partner and diagnosis of sexually transmitted infection; no consistent use of condoms with sex partner known to be hiv-1 positive. all subjects received monthly hiv-1 testing, risk-reduction counseling, condoms, and management of sexually transmitted infections. of the 2499 enrolled, 1251 received truvada and 1248 received placebo. the mean age of subjects was 27 years; 5% were asian, 9% black, 18% white, and 72% hispanic/latino. subjects were followed for 4,237 person-years. the primary outcome measure for the study was the incidence of documented hiv seroconversion. at the end of treatment, emergent hiv-1 seroconversion was observed in 131 subjects, of which 48 occurred in the truvada group and 83 occurred in the placebo group, indicating a 42% (95% ci: 18–60%) reduction in risk. risk reduction was found to be higher (53%; 95% ci: 34–72%) among subjects who reported previous unprotected anal intercourse (urai) at screening (732 and 753 subjects reported urai within the last 12 weeks at screening in the truvada and placebo groups, respectively). in a post-hoc case control study of plasma and intracellular drug levels in about 10% of study subjects, risk reduction appeared to be greatest in subjects with detectable intracellular tenofovir. efficacy was therefore strongly correlated with adherence. 14.3 partners prep trial the partners prep trial was a randomized, double-blind, placebo-controlled 3-arm trial conducted in 4,758 serodiscordant heterosexual couples in kenya and uganda to evaluate the efficacy and safety of tdf (n=1589) and ftc/tdf (n=1583) versus (parallel comparison) placebo (n=1586) in preventing hiv-1 acquisition by the uninfected partner. all subjects received monthly hiv-1 testing, evaluation of adherence, assessment of sexual behavior, and safety evaluations. women were also tested monthly for pregnancy. women who became pregnant during the trial had study drug interrupted for the duration of the pregnancy and while breastfeeding. the uninfected partner subjects were predominantly male (61–64% across study drug groups) and had a mean age of 33–34 years. following 7,827 person-years of follow up, 82 emergent hiv-1 seroconversions were reported, with an overall observed seroincidence rate of 1.05 per 100 person-years. of the 82 seroconversions, 13 and 52 occurred in partner subjects randomized to truvada and placebo, respectively. two of the 13 seroconversions in the truvada arm and 3 of the 52 seroconversions in the placebo arm occurred in women during treatment interruptions for pregnancy. the risk reduction for truvada relative to placebo was 75% (95% ci: 55–87%). in a post-hoc case control study of plasma drug levels in about 10% of study subjects, risk reduction appeared to be greatest in subjects with detectable plasma tenofovir. efficacy was therefore strongly correlated with adherence.

ther side (ndc 61958-0701-1). store at 25 °c (77 °f), excursions permitted to 15 °c–30 °c (59 °f–86 °f) (see usp controlled room temperature). keep container tightly closed dispense only in original container do not use if seal over bottle opening is broken or missing