Table 3.
Other Drugs Affecting Commonly used AEDs. Examples from Therapeutic Drug Classes of Clinical Importance
| Therapeutic Drug Classes | Affected AEDs | Mechanism of Interaction and Clinical Consequence |
|---|---|---|
| Antidepressants and antipsychotics | Enzyme inhibition leading to increased serum concentrations of AEDs | |
| Haloperidol, risperidone | Carbamazepine | |
| Chlorpromazine | Valproic acid | |
| Clomipramine | Carbamazepine, phenytoin, phenobarbital, valproic acid | |
| Sertraline | Carbamazepine, lamotrigine, phenytoin, valproic acid, | |
| Oral contraceptives | Lamotrigine, valproic acid (oxcarbazepine?) | Induction of metabolism (glucuronidation) and reduced serum concentrations of AEDs |
| Antimicrobal drugs | Enzyme inhibition by antimicrobal drugs leading to increased serum concentrations of AEDs | |
| Macrolides (clarithromycin, erythromycin, troleandomycin) | Carbamazepine | |
| Rifampicin | Lamotrigine | |
| Isoniazid | Carbamazepine, ethosuximide, phenytoin, valproic acid | |
| Others | ||
| Probenicid | Carbamazepine | Induction of metabolism and reduced serum concentrations of carbamazepine |
| Antacides | Gabapentin | Decreased absorption of gabapentin |
| Cimetidine | Reduction in excretion of gabapentin leading to a prolonged half-life | |
| Salicylates and naproxene | Tiagabine | Displacement of tiagabine from plasma proteins leading to a decrease in the total serum concentration of tiagabine but unchanged free concentration |