The antiepileptics carbamazepine, phenytoin, and phenobarbital lower the plasma concentration and the half life of<unk>  sulfoxide's R(+) enantiomer. + Antiepileptics and pharmacokinetics of<unk>  sulfoxide Drug Change in AUC Change in Cmax Carbamazepine 49% decrease 50–63% decrease Phenobarbitol 61% decrease 50–63% decrease Phenytoin 66% decrease 50–63% decrease The antacid cimetidine heightens serum<unk>  concentrations, increases the half life of<unk> , and doubles<unk>  sulfoxide levels in bile. It was originally thought to work by increasing<unk>  bioavailability directly; however, it is now known that cimetidine inhibits the breakdown of<unk>  sulfoxide by interfering with CYP3A4. The half-life of<unk>  sulfoxide thus increases from 7.4 hours to 19 hours. This might be a helpful interaction on more severe cases, because it boosts the potency of<unk> . Paradoxically, cimetidine also inhibits the absorption of<unk>  by reducing gastric acidity. Several other interactions exist. Corticosteroids increase the steady-state plasma concentration of<unk>  sulfoxide; dexamethasone, for example, can increase the concentration by 56% by inhibiting the elimination of<unk>  sulfoxide. The anti-parasitic praziquantel increases the maximum plasma concentration of<unk>  sulfoxide by 50%, and the anti-parasitic levamisole increases the AUC (total drug exposure) by 75%. Grapefruit inhibits the metabolism of<unk>  within the intestinal mucosa. Finally, long-term administration of the antiretroviral ritonavir, which works as a CYP3A4 inhibitor, decreases the maximum concentration of<unk>  in the plasma as well as the AUC.
Albendazole
Flubendazole
Tiabendazole
Mebendazole
Triclabendazole
Praziquantel
Pyrantel
Avermectin