In vitro undersøgelser viste, at levetiracetam og dets primære metabolit ikke hæmmer de vigtigste human lever cytochrom P450 isoformer (CYP3A4, 2A6, 2C9, 2C19, 2D6, 2E1 og 1A2), glucuronyltransferase (UGT1A1 og UGT1A6) og epoxid hydroxylase aktiviteter Desuden påvirker levetiracetam ikke in vitro glukuronidering af valproatsyre.
In vitro, levetiracetam and its primary metabolite have been shown not to inhibit the major human liver cytochrome P450 isoforms (CYP3A4, 2A6, 2C9, 2C19, 2D6, 2E1 and 1A2), glucuronyl transferase (UGT1A1 and UGT1A6) and epoxide hydroxylase activities.