From the Guidelines
For a patient weighing 14.6 kilograms, the recommended dose of cephalexin is 20 mg per kg per dose twice daily, which translates to approximately 292 mg per dose given twice daily, with a maximum dose of 500 mg per dose. According to the guidelines for managing group A streptococcal pharyngitis 1, cephalexin is recommended for patients with penicillin allergy, with a dosage of 20 mg per kg per dose twice daily. To calculate the dose for a patient weighing 14.6 kg, we multiply the weight by the recommended dose per kg: 14.6 kg * 20 mg/kg = 292 mg per dose, given twice daily. It's essential to note that the maximum dose per administration should not exceed 500 mg. Cephalexin is available in various formulations, including capsules and oral suspension, with the suspension being more suitable for pediatric patients. The treatment duration typically ranges from 10 days for group A streptococcal pharyngitis, as recommended by the guidelines 1. Cephalexin should be administered with or without food, though taking it with food may help reduce gastrointestinal side effects, such as diarrhea, nausea, and rash. As a first-generation cephalosporin antibiotic, cephalexin works by inhibiting bacterial cell wall synthesis and is effective against many gram-positive bacteria and some gram-negative bacteria. Key considerations for cephalexin use include:
- Dosage: 20 mg per kg per dose twice daily, not to exceed 500 mg per dose
- Treatment duration: typically 10 days for group A streptococcal pharyngitis
- Administration: with or without food
- Common side effects: diarrhea, nausea, rash
- Mechanism of action: inhibiting bacterial cell wall synthesis
- Spectrum of activity: effective against many gram-positive bacteria and some gram-negative bacteria.
From the FDA Drug Label
The usual recommended daily dosage for pediatric patients is 25 to 50 mg/kg in divided doses The recommended dose of cephalexin for a patient weighing 14.6 kilograms is 25 to 50 mg/kg in divided doses, which translates to 365 to 730 mg per day. For a patient of this weight, the dose can be divided into multiple doses per day, but the exact dosing frequency is not specified in the label for this weight. 2
From the Research
Cephalexin Dosing Information
- The recommended dose of cephalexin for a patient is not explicitly stated in the provided studies, but general information about cephalexin and its comparison to other antibiotics can be found 3, 4.
- Cephalexin is among the least potent and has the narrowest antimicrobial spectrum against pathogens evaluated, compared to other orally administered cephalosporins and amoxicillin/clavulanate 3.
- A study from a pharmacist's perspective discusses the principles of dose selection for antibiotics, including cephalexin, but does not provide specific dosing information for a 14.6 kg patient 5.
- Cephalexin was one of the antibiotics identified as being prescribed unnecessarily in the outpatient setting, but the study does not provide dosing information 4.
Relevant Studies
- A study comparing azithromycin, amoxicillin/clavulanic acid, and cefaclor in the treatment of acute ENT infections does not provide specific dosing information for cephalexin 6.
- A review of the spectrum and potency of orally administered cephalosporins and amoxicillin/clavulanate provides information on the antimicrobial spectrum of cephalexin, but not specific dosing information 3.
- A study on antibiotic stewardship targets in the outpatient setting identifies cephalexin as one of the antibiotics prescribed unnecessarily, but does not provide dosing information 4.