Cefalexin Oral: Dosing, Duration, and Precautions
Cefalexin guidance for common staphylococcal and streptococcal skin infections, including neonatal and pediatric dosing.
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Source reviewed
January 2024
Guide category
Oral drugs
Safety boundary
Prescription medicine information for clinician-guided use.
Kenza Health Hub presents this medicine page as structured health education. Check dose, route, interactions, pregnancy or breast-feeding considerations, and local protocol with a qualified clinician or pharmacist. Read our medical editorial policy.
Therapeutic action
First-generation cephalosporin antibacterial.
Indications
Skin infections due to staphylococci and/or streptococci: impetigo, furuncle, erysipelas, and superficial cellulitis.
Forms and strengths
- 250 mg capsule.
- 125 mg/5 ml powder for oral suspension to be reconstituted with filtered water and administered using a measuring device.
Dose
The exact dose should be calculated according to the newborn's weight.
- Neonate under 7 days: 25 mg/kg 2 times daily.
- Neonate 7 to 28 days: 25 mg/kg 3 times daily.
- Child 1 month to under 12 years: 12.5 to 25 mg/kg 2 times daily.
- Child 12 years and over and adult: 1 g 2 times daily.
- 1 to < 5 months and 4 to < 7 kg: 125 mg 2 times daily or 5 ml suspension 2 times daily.
- 5 months to < 3 years and 7 to < 15 kg: 187.5 mg 2 times daily or 7.5 ml suspension 2 times daily.
- 3 to < 6 years and 15 to < 20 kg: 250 mg 2 times daily or 10 ml suspension 2 times daily.
- 6 to < 12 years and 20 to < 40 kg: 500 mg 2 times daily or 2 capsules 2 times daily.
- >= 12 years and adult, >= 40 kg: 1 g 2 times daily or 4 capsules 2 times daily.
| Age | Weight | Daily dose | 125 mg/5 ml oral susp. | 250 mg capsule |
|---|---|---|---|---|
| 1 to < 5 months | 4 to < 7 kg | 125 mg x 2 | 5 ml x 2 | − |
| 5 months to < 3 years | 7 to < 15 kg | 187.5 mg x 2 | 7.5 ml x 2 | − |
| 3 to < 6 years | 15 to < 20 kg | 250 mg x 2 | 10 ml x 2 | - |
| 6 to < 12 years | 20 to < 40 kg | 500 mg x 2 | - | 2 cap x 2 |
| ≥ 12 years and adult | ≥ 40 kg | 1 g x 2 | - | 4 cap x 2 |
Duration
- Impetigo and furuncle: 7 days.
- Erysipelas and cellulitis: 7 to 10 days.
Contra-indications, adverse effects, precautions
- Do not administer to patients with allergy to cephalosporin.
- Administer with caution to patients with allergy to penicillin because cross-sensitivity may occur, and to patients with severe renal impairment by reducing the dose.
- May cause gastrointestinal disturbances, particularly diarrhoea, and allergic reactions such as skin eruption, fever, and pruritus.
- Pregnancy: no contra-indication.
- Breast-feeding: no contra-indication.
Source
MSF Essential drugs practical guidelines (January 2026)
This page combines source-derived medicine reference sections with Kenza editorial context, while leaving out the Storage and Remarks sections from the source batch.
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