PANIPENEM-BETAMIPRON AND DECREASES IN SERUM VALPROIC ACID CONCENTRATION

Serum concentrations of valproic acid (VPA) were reduced to 0% to 40% of the original levels by concomitant use with panipenem-betamipron (P AM-BP) in three patients. The serum VPA level began to decrease 2 days after the administration of PAPM-BP, and it began to increase within 24 hours of the last dose. The rapid change in the serum VPA level sug gests the existence of unique and as yet unknown mechanisms of interac tion between VPA and PAPM-BP. Epileptic seizures developed in two of t he three patients during PAPM-BP use, which signaled the dangers of PA PM-BP administration to patients concomitantly administered VPA. PAPM- BP should not be used in patients administered VPA.