Initially 5 mg daily in the morning for the 1st wk, increased wkly at 5-mg increments to a max dose of 20 mg daily. Dose ≥10 mg should be taken in 2 divided doses.
May increase incidence & severity of adverse effects w/ amantadine, ketamine or dextromethorphan. Enhanced effects of dopaminergics & antimuscarinics. May reduce actions of barbiturates & antipsychotics. May alter effects of antispasmodics, baclofen & dantrolene. Reduced clearance w/ carbonic anhydrase inhibitors & Na bicarbonate.