Ertapenem appears to dramatically and rapidly reduce
valproate levels resulting in increased seizure frequency.
It would be prudent to monitor
valproate levels in any patient given carbapenems. The
valproate dosage may need to be increased. Consider using another antibacterial, or an alternative to
valproate. Limited evidence suggests that
carbamazepine and
phenytoin do not interact. Note that
ertapenem should be used with caution in patients with a history of seizures.