MAY ENHANCE THE SEDATING EFFECTS OF OTHER CNS DEPRESSANTS, BARBITURATES, ANTIPSYCHOTIC DRUGS. HAS ADDITIVE ANTIMUSCARINIC EFFECT WITH ATROPINE AND TRICYCLIC AND MAO INHIBITORS. IT SHOULD NEVER BE GIVEN WITH DRUGS THAT INHIBIT ITS HEPATIC METABOLISM AND DRUGS THAT ARE ARRHYTHMOGENIC LIKE QUININE, ANTIDEPRESSANTS ETC.