Seizure worsening caused by decreased serum valproate during meropenem therapy.

Serum concentrations of valproate were reduced and seizures were exacerbated by concomitant meropenem therapy in a child with a neurodegenerative disorder and epilepsy. In this patient, a rapid decline of valproate serum concentrations was observed on two occasions with meropenem antibiotic therapy. This event was the most likely cause of observed seizure exacerbation. Meropenem should be used with caution in patients treated with valproate owing to the drastic lowering of serum valproate concentration and the consequent risk of seizure worsening.