<p>Olanzapine may antagonize the effects of levodopa and dopamine agonists. Drugs that induce CYP1A2 or glucoronyl transferase enzymes e.g, Omeprazole and Rifampicin, may increase Olanzapine clearance. Inhibitors of CYP1A2 may potentially inhibit Olanzapine elimination. Carbamazepine may increase the clearance of Olanzapine. Concomitant administration of activated charcoal reduces the oral bioavailability of Olanzapine by 50-60%. Caution should be taken when Olanzapine is administered with centrally acting drugs and alcohol.</p>