ugh the infectious agent is not always eliminated as judged by immunofluorescence. inclusion conjunctivitis caused by chlamydia trachomatis. uncomplicated urethral, endocervical or rectal infections in adults caused by chlamydia trachomatis. nongonococcal urethritis caused by ureaplasma urealyticum. relapsing fever due to borrelia recurrentis. doxycycline is also indicated for the treatment of infections caused by the following gram-negative microorganisms: chancroid caused by haemophilus ducreyi. plague due to yersinia pestis (formerly pasteurella pestis ). tuleremia due to francisella tulerensis (formerly pasteurella tulerensis ). cholera caused by vibrio cholerae (formerly vibrio comma ). campylobacter fetus infections caused by campylobacter fetus (formerly vibrio fetus ). brucellosis due to brucella species (in conjunction with streptomycin). bartonellosis due to bartonella baciliformis. granuloma inguinale caused by calymmatobacterium granulomatis. because many strains of the following groups of microorganisms have been shown to be resistant to doxycycline culture and susceptibility testing are recommended. doxycycline is indicated for treatment of infections caused by the following gram-negative microorganisms, when bacteriologic testing indicates appropriate susceptibility to the drug: escherichia coli. enterobacter aerogenes (formerly aerobacter aerogenes ). shigella species. acinetobacter species (formerly mima species and herellea species). respiratory tract infections caused by haemophilus influenzae. respiratory tract and urinary tract infections caused by klebsiella species. doxycycline is indicated for treatment of infections caused by the following gram-positive microorganisms when bacteriologic testing indicates appropriate susceptibility to the drug: upper respiratory infections caused by streptococcus pneumonie (formerly diplococcus pneumoniae ). anthrax due to bacillus anthracis, including inhalational anthrax (post-exposure): to reduce the incidence or progression of disease following exposure to aerosolized bacillus anthracis. when penicillin is contraindicated doxycycline is an alternative drug in the treatment of the following infections: uncomplicated gonorrhea caused by neisseria gonorrhoeae. syphilis caused by treponema pallidum. yaws caused by treponema pertenue. listeriosis due to listeria monocytogenes. vincent's infection caused by fusobacterium fusiforme. actinomycosis caused by actinomyces israelii. infections caused by clostridium species. in acute intestinal amebiasis, doxycycline may be a useful adjunct to amebicides. in severe acne, doxycycline may be useful adjunctive therapy. prophylaxis: doxycycline is indicated for the prophylaxis of malaria due to plasmodium falciparum in short-term travelers (<4 months) areas with chloroquine and/or pyrimethamine-sulfadoxine resistant strains. see dosage and administration section and information for patients subsection of the precautions section.

rtoxin producing strains of c. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. cdad must be considered in all patients who present with diarrhea following antibiotic use. careful medical history is necessary since cdad has been reported to occur over two months after the administration of antibacterial agents. if cdad is suspected or confirmed, ongoing antibiotic use not directed against c. difficile may need to be discontinued. appropriate fluid and electrolyte management protein supplementation, antibiotic treatment of c. difficile , and surgical evaluation should be instituted as clinically indicated. all tetracyclines form a stable calcium complex in any bone-forming tissue. a decrease in fibula growth rate has been observed in prematures given oral tetracycline in doses of 25 mg/kg every 6 hours. this reaction was shown to be reversible when the drug was discontinued. results of animal studies indicate that tetracyclines cross the placenta, are found in fetal tissues, and can have toxic effects on the developing fetus (often related to retardation of skeletal development). evidence of embryotoxicity has also been noted in animals treated early in pregnancy. if any tetracycline is used during pregnancy or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. the antianabolic action of the tetracyclines may cause an increase in bun. studies to date indicate that this does not occur with the use of doxycycline in patients with impaired renal function. photosensitivity manifested by an exaggerated sunburn reaction has been observed in some individuals taking tetracyclines. patients apt to be exposed to direct sunlight or ultraviolet light should be advised that this reaction can occur with tetracycline drugs, and treatment should be discontinued at the first evidence of skin erythema.

ovide benefit to the patient and increases the risk of the development of drug-resistant bacteria.

may be used. for children over 100 lb the usual adult dose should be used. the therapeutic antibacterial serum activity will usually persist for 24 hours following recommended dosage. when used in streptococcal infections, therapy should be continued for 10 days. administration of adequate amounts of fluid along with capsule and tablet forms of drugs in the tetracycline class is recommended to wash down the drugs and reduce the risk of esophageal irritation and ulceration. (see adverse reactions ). if gastric irritation occurs, it is recommended that doxycycline be given with food or milk. the absorption of doxycycline is not markedly influenced by simultaneous ingestion of food or milk. studies to date have indicated that administration of doxycycline at the usual recommended doses does not lead to excessive accumulation of the antibiotic in patients with renal impairment. uncomplicated gonococcal infections in adults (except anorectal infections in men): 100 mg, by mouth, twice a day for 7 days. as an alternate single visit dose, administer 300 mg stat followed in one hour by a second 300 mg dose. the dose may be administered with food, including milk or carbonated beverage, as required. uncomplicated urethral, endocervical, or rectal infection in adults caused by chlamydia trachomatis: 100 mg, by mouth, twice a day for 7 days. nongonococcal urethritis (ngu) caused by c. trachomatis and u. urealyticum: 100 mg, by mouth, twice a day for 7 days. syphilis - early: patients who are allergic to penicillin should be treated with doxycycline 100 mg by mouth twice a day for 2 weeks. syphilis of more than one year's duration: patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 4 weeks. acute epididymo-orchitis caused by n. gonorrhoeae : 100 mg, by mouth, twice a day for at least 10 days. acute epididymo-orchitis caused by c. trachomatis : 100 mg, by mouth, twice a day for at least 10 days. for the prophylaxis of malaria: for adults, the recommended dose is 100 mg daily. for children over 8 years of age, the recommended dose is 2 mg/kg given once daily up to the adult dose. prophylaxis should begin 1 to 2 days before travel to the malarious area. prophylaxis should be continued daily during travel in the malarious area and for 4 weeks after the traveler leaves the malarious area. inhalational anthrax (post-exposure): adults: 100 mg of doxycycline, by mouth, twice a day for 60 days. children: weighing less than 100 lb (45 kg); 1 mg/lb (2.2 mg/kg) of body weight, by mouth, twice a day for 60 days. children weighing 100 lb or more should receive the adult dose.

hotosensitivity is discussed above. (see warnings ). renal toxicity: rise in bun has been reported and is apparently dose related. (see warnings ). hypersensitivity reactions: urticaria, angioneurotic edema, anaphylaxis, anaphylactoid purpura, serum sickness, pericarditis, and exacerbation of systemic lupus erythematosus. blood: hemolytic anemia, thrombocytopenia, neutropenia, and eosinophilia have been reported. other: bulging fontanels in infants and intracranial hypertension in adults. (see precautions - general ). when given over prolonged periods, tetracyclines have been reported to produce brown-black microscopic discoloration of the thyroid gland. no abnormalities of thyroid function studies are known to occur. to report suspected adverse reactions, contact west-ward pharmaceutical corp. at 1-877-233-2001, or the fda at 1-800-fda-1088 or www.fda.gov/medwatch.

cate that tetracyclines cross the placenta and are found in fetal tissues. microbiology the tetracyclines are primarily bacteriostatic and are thought to exert their antimicrobial effect by the inhibition of protein synthesis. the tetracyclines, including doxycycline, have a similar antimicrobial spectrum of activity against a wide range of gram-positive and gram-negative organisms. cross-resistance of these organisms to tetracyclines is common. gram-negative bacteria neisseria gonorrhoeae calymmatobacterium granulomatis haemophilus ducreyi haemophilus influenzae yersinia pestis (formerly pasteurella pestis ) francisella tularensis (formerly pasteurelia tularensis ) vibrio cholera (formerly vibrio comma ) bartonella bacilliformis brucella species because many strains of the following groups of gram-negative microorganisms have been shown to be resistant to tetracyclines, culture and susceptibility testing are recommended: escherichia coli klebsiella species enterobacter aerogenes shigella species acinetobacter species (formerly mima species and herellea species) bacteroides species gram-positive bacteria because many strains of the following groups of gram-positive microorganisms have been shown to be resistant to tetracycline, culture and susceptibility testing are recommended. up to 44 percent of strains of streptococcus pyogenes and 74 percent of streptococcus faecalis have been found to be resistant to tetracycline drugs. therefore, tetracycline should not be used for streptococcal disease unless the organism has been demonstrated to be susceptible. streptococcus pyogenes streptococcus pneumoniae enterococcus group ( streptococcus faecalis and streptococcus faecium ) alpha-hemolytic streptococci (viridans group) other microorganisms rickettsiae clostridium species chlamydia psittaci fusobacterium fusiforme chlamydia trachomatis actinomyces species mycoplasma pneumoniae bacillus anthracis ureaplasma urealyticum propionibacterium acnes borrelia recurrentis entamoeba species treponema pallidum balantidium coli treponema pertenue plasmodium falciparum doxycycline has been found to be active against the asexual erythrocytic forms of plasmodium falciparum but not against the gametocytes of p. falciparum. the precise mechanism of action of the drug is not known. susceptibility tests: diffusion techniques quantitative methods that require measurement of zone diameters give the most precise estimate of the susceptibility of bacteria to antimicrobial agents. one such standard procedure 1 which has been recommended for use with disks to test susceptibility of organisms to doxycycline, uses the 30-mcg tetracycline-class disk or the 30-mcg doxycycline disk. interpretation involves the correlation of the diameter obtained in the disk test with the minimum inhibitory concentration (mic) for tetracycline or doxycycline, respectively. reports from the laboratory giving results of the standard single-disk susceptibility test with a 30-mcg tetracycline-class disk the 30-mcg doxycycline disk should be interpreted according to the following criteria: zone diameter (mm) interpretation tetracycline doxycycline ≥19 ≥16 susceptible 15-18 13-15 intermediate ≤14 ≤12 resistant a report of "susceptible" indicates that the pathogen is likely to be inhibited by generally achievable blood levels. a report of "intermediate" suggests that the organism would be susceptible if a high dosage is used or if the infection is confined to tissues and fluids in which antimicrobial levels are attained. a report of "resistant" indicates that achievable concentrations are unlikely to be inhibitory, and other therapy should be selected. standardized procedures require the use of laboratory control organisms. the 30-mcg tetracycline-class disk or the 30-mcg doxycycline disk should give the following zone diameters: organism zone diameter (mm) tetracycline doxycycline e. coli atcc 25922 18-25 18-24 s. aureus atcc 25923 19-28 23-29 dilution techniques use a standardized dilution method 2 (broth, agar, microdilution) or equivalent with tetracycline powder. the mic values obtained should be interpreted according to the following criteria: mic (mcg/ml) interpretation ≤4 susceptible 8 intermediate ≥16 resistant as with standard diffusion techniques, dilution methods require the use of laboratory control organisms. standard tetracycline powder should provide the following mic values: organism mic (mcg/ml) e. coli atcc 25922 1.0-4.0 s. aureus atcc 29213 0.25-1.0 e. faecalis atcc 29212 8-32 p. aeruginosa atcc 27853 8-32

., skin eruption, etc.) occurs. sunscreen or sunblock should be considered (see warnings ). - to drink fluids liberally along with doxycycline to reduce the risk of esophageal irritation and ulceration. (see adverse reactions ). - that the absorption of tetracyclines is reduced when taken with foods, especially those which contain calcium. however, the absorption of doxycycline is not markedly influenced by simultaneous ingestion of food or milk. (see drug interactions. ) - that the absorption of tetracyclines is reduced when taking bismuth subsalicylate (see drug interactions. ) - that the use of doxycycline might increase the incidence of vaginal candidiasis. patients should be counseled that antibacterial drugs including doxycycline hyclate should only be used to treat bacterial infections. they do not treat viral infections (e.g., the common cold). when doxycycline is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by doxycycline hyclate or other antibacterial drugs in the future. diarrhea is a common problem caused by antibiotics which usually ends when the antibiotic is discontinued. sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as two or more months after having taken the last dose of the antibiotic. if this occurs, patients should contact their physician as soon as possible.