From the FDA Drug Label
Cephalexin should be administered with caution in the presence of markedly impaired renal function. Under such conditions, careful clinical observation and laboratory studies should be made because safe dosage may be lower than that usually recommended.
Administration of Keflex to a patient on dialysis requires caution. The patient's renal function is markedly impaired, and the drug label recommends careful clinical observation and laboratory studies to determine a safe dosage, which may be lower than usual. 1
From the Research
Keflex (cephalexin) can be given to patients on dialysis, but dose adjustments are necessary to avoid toxicity and ensure efficacy. The most recent and highest quality study 2 provides guidance on antibiotic dosing in patients receiving haemodialysis, which can be applied to keflex dosing. For patients on hemodialysis, the recommended dose is 250-500 mg every 12 hours, with a supplemental dose after dialysis sessions. For peritoneal dialysis patients, 250-500 mg every 12-24 hours is typically appropriate.
Key Considerations
- The adjustment is necessary because cephalexin is primarily eliminated by the kidneys, and impaired renal function in dialysis patients leads to drug accumulation if standard doses are used.
- Without proper adjustment, this could result in toxicity, including neurotoxic effects like seizures.
- When prescribing Keflex to dialysis patients, it's essential to monitor for side effects such as gastrointestinal disturbances and hypersensitivity reactions, and to consider potential drug interactions with other medications commonly used in this population.
- The specific dosing should be individualized based on the patient's residual renal function, dialysis modality, and the severity of the infection being treated.
Dosing Recommendations
- For patients on hemodialysis: 250-500 mg every 12 hours, with a supplemental dose after dialysis sessions.
- For peritoneal dialysis patients: 250-500 mg every 12-24 hours.
Monitoring and Precautions
- Monitor for side effects such as gastrointestinal disturbances and hypersensitivity reactions.
- Consider potential drug interactions with other medications commonly used in this population.
- Individualize dosing based on the patient's residual renal function, dialysis modality, and the severity of the infection being treated.