Bacterial infections:

Indications for: Cephalexin

Susceptible infections including otitis media, skin and skin structure, bone, respiratory or genitourinary tract.

Adult Dosage:

≥15yrs: usually 250mg every 6hrs; may give 500mg every 12hrs. Treat for 7–14 days. Severe infections: up to 4g/day in 2–4 equally divided doses. Renal impairment (CrCl 30–59mL/min): max 1g/day; (CrCl 15–29mL/min): 250mg every 8hrs or 12hrs; (CrCl 5–14mL/min, no dialysis): 250mg every 24hrs; (CrCl 1–4mL/min, no dialysis): 250mg every 48hrs or 60hrs.

Children Dosage:

Give in equally divided doses. >1yr: 25–50mg/kg/day. Treat for 7–14 days. β-hemolytic strep: treat for ≥10 days. Severe infections: 50–100mg/kg/day. Otitis media: 75–100mg/kg/day.

Cephalexin Warnings/Precautions:

Penicillin or other allergy. Risk of seizures (esp. in renal impairment); discontinue if occurs. Poor nutritional state. Renal impairment (CrCl <30mL/min, with or without dialysis): monitor. Pregnancy. Nursing mothers.

Cephalexin Classification:


Cephalexin Interactions:

Concomitant probenecid: not recommended. Potentiates metformin (monitor and adjust metformin dose). May cause false (+) glucose test with Benedict's or Fehling's soln.

Adverse Reactions:

GI upset, abdominal pain; hypersensitivity reactions (discontinue if occur), C. difficile-associated diarrhea, hemolytic anemia. positive Coombs' test, prolonged prothrombin time (monitor).


Formerly known under the brand name Keflex.

How Supplied:

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Pricing for Cephalexin

500mg capsule (Qty: 28)
Appx. price $11