an introduction Cephalexin is a cephalosporin antibiotic. It works by killing bacteria in the body. Cefalexin is used to treat infections caused by bacteria, including upper respiratory tract infections, ear infections, skin infections, urinary tract infections, and bone infections. Cefalexin may also be used for purposes not listed in this medication guide. Instructions for taking cephalexin Usage and dosage 1. grown ups Prevention of bacterial endocarditis 2 grams orally 30-60 minutes before surgery impetigo 250 mg orally every 6 hours or 500 mg every 12 hours for 7-14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. (staphylococcal and streptococcal) 250 mg orally 4 times daily for 7 days, depending on clinical response Infection of the skin and/or subcutaneous tissue 250 mg orally every 6 hours or 500 mg every 12 hours for 7-14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. (Methicillin-sensitive Staphylococcus aureus or Streptococcus) 500 mg orally 4 times daily Osteomyelitis 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. Inflammation of the middle ear 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. respiratory infection 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. streptococcal pharyngitis; 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. Urinary tract infection 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days Severe infections: Up to 4 g/day in 2-4 equally divided doses for 7 to 14 days. 2. children Prevention of bacterial endocarditis 50 mg/kg orally 30-60 minutes before surgery impetigo (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days (staphylococci and streptococci) 25-50 mg/kg/day orally in 3 or 4 divided doses for 7 days, depending on clinical response Infection of the skin and/or subcutaneous tissue (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days (lamethicillin-sensitive Staphylococcus aureus): 25-50 mg/kg/day orally in 4 divided doses Osteomyelitis (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days Inflammation of the middle ear (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days respiratory infection (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days (community-acquired pneumonia over 3 months of age), 75-100 mg/kg/day orally in 3-4 divided doses streptococcal pharyngitis; (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days Urinary tract infection (Older than 1 year to 14 years): 25-50 mg/kg/day in equal divided doses orally for 7 to 14 days. In severe infections, 50-100 mg/kg/day orally in equal divided doses. (15 years and older): 250 mg orally every 6 hours or 500 mg every 12 hours for 7 to 14 days 15) years and over) Acute infections: up to 4 g/day in 2-4 equally divided doses for 7 to 14 days Dosage adjustments Renal impairment in patients 15 years of age or older, (creatinine clearance 60 mL/min or greater): No modification necessary Renal impairment in patients 15 years of age or older, (creatinine clearance 59 - 30 mL/min or greater): No modification necessary; But the dose should not exceed 1 gram / day Renal impairment, in patients 15 years of age or older, (creatinine clearance 15-29 mL/min or more): 250 mg every 8 or 12 hours Renal impairment in patients 15 years of age or older, (creatinine clearance 14-5 mL/min or greater) not on dialysis: 250 mg/day Renal impairment in patients 15 years of age or older, (creatinine clearance 1-4 mL/min or greater) not undergoing hemodialysis: 250 mg/48 hours or 60 hours Warnings when taking cephalexin Contraindications / Warnings contraindications Hypersensitivity to cephalexin or other cephalosporins Precautions It is not recommended to use probenecid at the same time as cephalexin Gastrointestinal: Clostridium difficile-associated diarrhea may sometimes be fatal, sometimes occurring after more than 2 months of treatment. Digestive System: Use with caution in patients with a history of or suffering from gastrointestinal diseases, especially colitis Haematological: May prolong prothrombin time, especially in patients with hepatic or renal failure, poor nutritional status, or a prolonged course of antimicrobial therapy, or anticoagulant therapy. Haematological: Acute intravascular haemolysis induced by treatment with cephalexin Immune system: anaphylaxis, Stevens-Johnson syndrome, or toxic epidermal necrolysis Immune system: bacteria developing themselves to be resistant to drugs Neurological: convulsions may occur, especially in patients with renal insufficiency Renal: Caution should be exercised in patients with creatinine clearance less than 30 mL/min with or without hemodialysis. pregnancy A risk to the fetus cannot be ruled out Breastfeeding A risk to infants cannot be ruled out Cephalexin side effects side effects common Gastrointestinal: diarrhea dangerous Cutaneous: Stevens-Johnson syndrome, toxic epidermal necrolysis Digestive system: colitis Blood: increased prothrombin time Immune system: allergic reaction, anaphylaxis Nervousness: convulsions Kidney: interstitial nephritis, renal failure