amantadine, ketamine, dextromethorphan dantrolene, baclofen cimetidine, ranitidine, procainamide, quinidine, quinine, nicotine hydrochlorothiazide (or any combination with hydrochlorothiazide) anticholinergics (substances generally used to treat movement disorders or intestinal cramps) anticonvulsants (substances used to prevent and relieve seizures) barbiturates (substances generally used to induce sleep) dopaminergic agonists (substances such as L-dopa, bromocriptine) neuroleptics (substances used in the treatment of mental disorders) oral anticoagulants