Populations at risk for penicillin-induced seizures.

OBJECTIVE: This article reviews principles associated with penicillin's epileptogenic activity in an effort to alert clinicians of patients at high risk for penicillin-induced seizures. The case presentation exemplifies the most prevalent factor predisposing patients to penicillin-induced seizures--renal impairment. DATA SOURCES: References are identified from pertinent articles and books. DATA SYNTHESIS: The epileptogenic properties of penicillin are explained on the basis of the beta-lactam ring's binding to gamma aminobutyric acid receptors. Several patient populations are at risk for potentially fatal neurotoxic symptoms. Most of these patients demonstrate impaired renal function, either as the primary condition or secondary to an infectious process. The other at-risk populations include infants and the elderly, patients with meningitis, patients undergoing intraventricular antibiotic therapy, and patients with a history of seizures. Treatment remains controversial; however, benzodiazepines theoretically produce a favorable response.
CONCLUSIONS: Pharmacokinetic parameters explain patient populations most at risk; a guideline equation has been recommended to allow clinicians to make appropriate dose adjustments based on creatinine clearance. Physicians and pharmacists must recognize the populations most at risk for high-dose, penicillin-induced neurotoxicities; monitor these patients at least during the first 72 hours, and reduce or discontinue therapy when appropriate.