From the Guidelines
For a 47-pound child with a skin infection of the finger, the recommended dose of cephalexin is 25 mg/kg/day in 4 divided doses po, as indicated in the practice guidelines for the diagnosis and management of skin and soft-tissue infections 1.
Key Considerations
- The child's weight is 47 pounds, which is approximately 21.3 kg.
- The recommended dose of cephalexin for children is 25 mg/kg/day in 4 divided doses po, according to the guidelines 1.
- This translates to a total daily dose of approximately 532.5 mg, divided into 4 equal doses of approximately 133.1 mg each.
Administration and Duration
- Cephalexin should be administered orally, at regular 6-hour intervals, to maintain optimal drug levels.
- The typical duration of treatment for skin infections is 7-10 days, depending on the clinical response.
Important Safety Information
- Cephalexin is generally well-tolerated, but common side effects may include diarrhea, stomach upset, or rash.
- If the child has a history of allergic reaction to penicillins or other cephalosporins, cephalexin should be avoided.
- Parents should seek immediate medical attention if the infection worsens, if the child develops fever, or if a rash appears after starting the medication.
Mechanism of Action
- Cephalexin works by inhibiting bacterial cell wall synthesis, making it effective against many common skin pathogens, including Staphylococcus and Streptococcus species 1.
From the FDA Drug Label
Pediatric Patients The usual recommended daily dosage for pediatric patients is 25 to 50 mg/kg in divided doses For streptococcal pharyngitis in patients over 1 year of age and for skin and skin structure infections, the total daily dose may be divided and administered every 12 hours.
Cephalexin Suspension Weight125 mg/5 mL250 mg/5 mL 10 kg (22 lb)1/2 to 1 tsp q.i.d.1/4 to 1/2 tsp q.i.d. 20 kg (44 lb)1 to 2 tsp q.i.d.1/2 to 1 tsp q.i.d. 40 kg (88 lb)2 to 4 tsp q.i.d.1 to 2 tsp q.i. d. or Weight125 mg/5 mL250 mg/5 mL 10 kg (22 lb)1 to 2 tsp b.i.d.1/2 to 1 tsp b.i.d 20 kg (44 lb)2 to 4 tsp b.i.d.1 to 2 tsp b.i.d. 40 kg (88 lb)4 to 8 tsp b.i.d.2 to 4 tsp b.i. d.
The correct dose of cephalexin for a 47-pound child with a skin infection of the finger is between 25 to 50 mg/kg in divided doses. Since the child weighs 47 pounds, which is approximately 21.3 kg, the total daily dose would be between 532.5 mg and 1065 mg. This can be divided and administered every 12 hours. For a child of this weight, the dose would be closer to the dose recommended for a 20 kg (44 lb) child, which is 2 to 4 tsp b.i.d. for the 125 mg/5 mL suspension or 1 to 2 tsp b.i.d. for the 250 mg/5 mL suspension 2.
From the Research
Cephalexin Dosage for a 47-Pound Child with a Skin Infection
- The provided studies do not directly address the correct dose of cephalexin for a 47-pound child with a skin infection of the finger.
- However, 3 discusses the principles of dose selection for antibiotics, including cephalexin, from a pharmacist's perspective, considering factors such as microbiological data, site of infection, pharmacokinetics, and pharmacodynamic targets.
- 4 reviews the antimicrobial spectrum and potency of orally administered cephalosporins, including cephalexin, but does not provide specific dosage information for children.
- The other studies 5, 6, 7 focus on different topics, such as antibiotic susceptibility of periodontal Enterococcus faecalis, selection of empiric antibiotic regimens for hematogenous vertebral osteomyelitis, and oral antibiotic susceptibility patterns of urinary tract infections in infants, and do not provide relevant information on cephalexin dosage for a child with a skin infection.