Drug-drug interaction between valproic acid and meropenem: a retrospective analysis of electronic medical records from neurosurgery inpatients

This is the first study using a large number of VPA TDM records to investigate the change in VPA levels caused by concomitant use of MEPM. Our results imply that the decrease in drug concentration cannot be reversed by increasing VPA dose. Moreover, MEPM daily dose did not influence the drop in VPA plasma level. At least 7 days are required for the recovery of VPA plasma concentration after discontinuation of MEPM.