cephalexin, Keflex (cont.)

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DOSING: The dose of cephalexin for adults is 1 to 4 grams in divided doses. The usual adult dose is 250 mg every 6 hours. Some infections may be treated with 500 mg every 12 hours. Children are treated with 25-100 mg/kg/day in divided doses. The dosing interval may be every 6 or 12 hours depending on the type and seriousness of the infection.

DRUG INTERACTIONS: Serious interactions of cephalexin with other drugs are uncommon.

PREGNANCY: There are no good studies of cephalexin in pregnant women. Cephalexin should only be used during pregnancy if there are no other safe alternatives.

NURSING MOTHERS: Cephalexin is excreted in breast milk. Cephalexin should be used with caution or stopped when breastfeeding.

SIDE EFFECTS: The most common side effects of cephalexin are diarrhea, nausea, abdominal pain, vomiting, headaches, dizziness, skin rash, fever, abnormal liver tests, and vaginitis. Individuals who are allergic to penicillin may also be allergic to cephalexin. Serious but rare reactions include seizures, severe allergic reactions (anaphylaxis), and low platelet or red blood cell count.

Cephalexin, like almost all antibiotics, may cause mild or severe cases of pseudomembranous colitis, a mild to severe inflammation of the colon. Antibiotics, including cephalexin alter the types of bacteria in the colon and permit overgrowth of a bacterium called Clostridium difficile. Studies indicate that a toxins produced by Clostridium difficile are a primary cause of pseudomembranous colitis.

Reference: FDA Prescribing Information


Medically Reviewed by a Doctor on 7/30/2014


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