acute prostatitis, caused by escherichia coli, proteus mirabilis, and klebsiella pneumoniae note: culture and susceptibility tests should be initiated prior to and during therapy. renal function studies should be performed when indicated. to reduce the development of drug-resistant bacteria and maintain the effectiveness of cephalexin and other antibacterial drugs, cephalexin capsules should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. when culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. in the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

ylaxis) to both drugs. any patient who has demonstrated some form of allergy, particularly to drugs, should receive antibiotics cautiously. no exception should be made with regard to cephalexin capsules. clostridium difficile associated diarrhea (cdad) has been reported with use of nearly all antibacterial agents, including cephalexin, and may range in severity from mild diarrhea to fatal colitis. treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of c. difficile . c. difficile produces toxins a and b which contribute to the development of cdad. hypertoxin 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.

tests are performed on the minor side or in coombs’ testing of newborns whose mothers have received cephalosporin antibiotics before parturition, it should be recognized that a positive coombs’ test may be due to the drug. cephalexin capsules should be administered with caution in the presence of markedly impaired renal function. under such conditions, careful clinical observation and laboratory studies should be made because safe dosage may be lower than that usually recommended. indicated surgical procedures should be performed in conjunction with antibiotic therapy. broad-spectrum antibiotics should be prescribed with caution in individuals with a history of gastrointestinal disease, particularly colitis. cephalosporins may be associated with a fall in prothrombin activity. those at risk include patients with renal or hepatic impairment, or poor nutritional state, as well as patients receiving a protracted course of antimicrobial therapy, and patients previously stabilized on anticoagulant therapy. prothrombin time should be monitored in patients at risk and exogenous vitamin k administered as indicated.

and skin structure infections, the total daily dose may be divided and administered every 12 hours. in severe infections, the dosage may be doubled. in the therapy of otitis media, clinical studies have shown that a dosage of 75 to 100 mg/kg/day in 4 divided doses is required. in the treatment of β-hemolytic streptococcal infections, a therapeutic dosage of cephalexin should be administered for at least 10 days.

ache, agitation, confusion, hallucinations, arthralgia, arthritis, and joint disorder. reversible interstitial nephritis has been reported rarely. eosinophilia, neutropenia, thrombocytopenia, hemolytic anemia, and slight elevations in ast and alt have been reported. in addition to the adverse reactions listed above that have been observed in patients treated with cephalexin, the following adverse reactions and altered laboratory tests have been reported for cephalosporin class antibiotics: adverse reactions — fever, colitis, aplastic anemia, hemorrhage, renal dysfunction, and toxic nephropathy. several cephalosporins have been implicated in triggering seizures, particularly in patients with renal impairment when the dosage was not reduced (see indications and usage and precautions , general section). if seizures associated with drug therapy should occur, the drug should be discontinued. anticonvulsant therapy can be given if clinically indicated. altered laboratory tests — prolonged prothrombin time, increased bun, increased creatinine, elevated alkaline phosphatase, elevated bilirubin, elevated ldh, pancytopenia, leukopenia, and agranulocytosis.

sage section. aerobes, gram-positive: staphylococcus aureus (including penicillinase-producing strains) streptococcus pneumoniae (penicillin-susceptible strains) streptococcus pyogenes aerobes, gram-negative: escherichia coli haemophilus influenzae klebsiella pneumoniae moraxella (branhamella) catarrhalis proteus mirabilis note: methicillin-resistant staphylococci and most strains of enterococci ( enterococcus faecalis [formerly streptococcus faecalis ]) are resistant to cephalosporins, including cephalexin. it is not active against most strains of enterobacter spp., morganella morganii , and proteus vulgaris . it has no activity against pseudomonas spp. or acinetobacter calcoaceticus . penicillin-resistant streptococcus pneumoniae is usually cross-resistant to beta-lactam antibiotics. susceptibility tests dilution techniques — quantitative methods are used to determine antimicrobial minimal inhibitory concentrations (mic’s). these mic’s provide estimates of the susceptibility of bacteria to antimicrobial compounds. the mic’s should be determined using a standardized procedure. standardized procedures are based on a dilution method 1-3 (broth or agar) or equivalent with standardized inoculum concentrations and standardized concentrations of cephalothin powder. the mic values should be interpreted according to the following criteria: mic (µg/ml) interpretation ≤8 susceptible (s) 16 intermediate (i) ≥32 resistant (r) a report of "susceptible" indicates that the pathogen is likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable. a report of "intermediate" indicates that the result should be considered equivocal, and, if the microorganism is not fully susceptible to alternative, clinically feasible drugs, the test should be repeated. this category implies possible clinical applicability in body sites where the drug is physiologically concentrated or in situations where high dosage of drug can be used. this category also provides a buffer zone which prevents small uncontrolled technical factors from causing major discrepancies in interpretation. a report of "resistant" indicates that the pathogen is not likely to be inhibited if the antimicrobial compound in the blood reaches the concentrations usually achievable; other therapy should be selected. standardized susceptibility test procedures require the use of laboratory control microorganisms to control the technical aspects of the laboratory procedures. standard cephalothin powder should provide the following mic values: microorganism mic (µg/ml) e. coli atcc 25922 4 to 16 s. aureus atcc 29213 0.12 to 0.5 diffusion techniques — quantitative methods that require measurement of zone diameters also provide reproducible estimates of the susceptibility of bacteria to antimicrobial compounds. one such standardized procedure 2,3 requires the use of standardized inoculum concentrations. this procedure uses paper disks impregnated with 30µg cephalothin to test the susceptibility of microorganisms to cephalexin. reports from the laboratory providing results of the standard single-disk susceptibility test with a 30 µg cephalothin disk should be interpreted according to the following criteria: zone diameter (mm) interpretation ≥18 susceptible (s) 15 to 17 intermediate (i) ≤14 resistant (r) interpretation should be as stated above for results using dilution techniques. interpretation involves correlation of the diameter obtained in the disk test with the mic for cephalexin. as with standard dilution techniques, diffusion methods require the use of laboratory control microorganisms that are used to control the technical aspects of the laboratory procedures. for the diffusion technique, the 30µg cephalothin disk should provide the following zone diameters in these laboratory test quality control strains: microorganism zone diameter (mm) e. coli atcc 25922 15 to 21 s. aureus atcc 29213 29 to 37