From the Guidelines
For a 69 kg man with GFR 37 mL/min and creatinine 149 μmol/L with a simple soft tissue skin infection, the recommended Keflex (cephalexin) dosing would be 500 mg orally every 12 hours. This dosing adjustment is necessary due to the moderate renal impairment (GFR between 30-59 mL/min) 1. The typical duration for treating a simple soft tissue infection would be 7-10 days, with reassessment after 48-72 hours to ensure clinical improvement. It's essential to complete the full course of antibiotics even if symptoms improve before completion. Patients should take the medication with food if stomach upset occurs, though it can be taken without food. Adequate hydration should be maintained during treatment. Some key points to consider when administering Keflex to patients with renal impairment include:
- Monitoring for signs of toxicity, such as diarrhea, nausea, and allergic reactions, especially in patients with penicillin allergies due to cross-reactivity 1
- Ensuring adequate hydration to prevent further renal impairment
- Regularly assessing renal function and adjusting the dose as necessary
- Being aware of potential drug interactions with other medications that may affect renal function. It is crucial to note that while the provided evidence does not directly address cephalexin dosing in renal impairment, the principles of adjusting doses based on renal function can be applied, and the recommendation is made based on the understanding of how renal impairment affects drug elimination and the potential for toxicity 1.
From the FDA Drug Label
The usual adult dose is 250 mg every 6 hours For the following infections, a dosage of 500 mg may be administered every 12 hours: streptococcal pharyngitis, skin and skin structure infections, and uncomplicated cystitis in patients over 15 years of age.
The typical dosing for a 69 kg man with a simple soft tissue skin infection is 500 mg every 12 hours.
- The patient's GFR of 37 and creatinine of 149 are not directly addressed in the provided drug label for dosing adjustments. 2
From the Research
Keflex Dosing for Simple Soft Tissue Skin Infection
- For a 69 kg man with a GFR of 37 and creatinine of 149, the typical keflex dosing is not directly stated in the provided studies.
- However, according to the study 3, the pharmacokinetic distribution of cephalosporin compounds, including cephalexin (Keflex), is affected by renal function.
- The study 3 suggests that the mean serum half-life of cephalexin increases as the rate of creatinine clearance decreases, indicating the need for dose adjustment in patients with reduced renal function.
- The study 4 investigated the clinical outcomes of failing to dose-reduce cephalosporin antibiotics, including cephalexin, in older adults with chronic kidney disease (CKD) and found that receiving a higher than recommended dose was not associated with a different rate of side-effects, treatment failure, or death.
- The study 5 provides guidance on antibiotic prescription in chronic kidney disease patients, including dose adjustments for patients with renal failure, but does not specifically address keflex dosing.
- The studies 6 and 7 do not provide direct information on keflex dosing for simple soft tissue skin infections in patients with reduced renal function.