Keflex is a first generation cephalosporin antibiotic of broad-spectrum. It has bactericidal action. Keflex is active against gram-positive bacteria: Staphylococcus spp. (Strains producing and not producing penicillinase), Streptococcus spp. (Including Streptococcus pneumoniae), Corynebacterium diphtheriae; Gram-negative bacteria: Neisseria meningitidis, Neisseria gonorrhoeae, Shigella spp., Salmonella spp., Escherichia coli. Inactive against Haemophilus influenzae, Proteus spp. (Indole-positive strains), Mycobacterium tuberculosis, anaerobic microorganisms. After oral administration is well absorbed from the gastrointestinal tract. Absorption is 90%. Acid-cephalexin, meal slows absorption, but does not affect its completeness. Bioavailability is 95%. Cmax achieved after - 1-2 hours after oral administration of 250 mg, 500 mg, 1 g Cmax is 9, 18, and 32 ug / ml, respectively. Keflex relatively uniformly distributed in various tissues and body fluids: lungs, bronchial mucosa, liver, heart and kidneys. The dosage is determined individually, taking into account the severity and localization of infection, the sensitivity of the pathogen. Average administered dose of Keflex for adults is 250-500 mg every 6-12 hours, if necessary the daily dose can be increased to 4-6, the duration of treatment is 7-14 days. In children with a body weight less than 40 kg average daily dose is 25-50 mg / kg, the number of intakes to 4 times a day. In severe infections the daily dose may be increased to 100 mg / kg, and the receive frequency up to 6 times a day. For infections caused by beta-hemolytic streptococcus group A, the minimum duration of treatment is 10 days. With simultaneous use of average enhances the effect of indirect anticoagulants. With simultaneous use of cephalexin increases nephrotoxicity of aminoglycosides, polymyxins, phenylbutazone, furosemide. Salicylates and indomethacin slow excretion of cephalexin. Side effects of the CNS include weakness, agitation, hallucinations, convulsions, headache, dizziness, drowsiness, and in rare cases, hallucinations. Urinary tract interstitial nephritis.