DEXTROMETHORPHAN AND MAOIS

Two fatal cases of hyperpyrexia and coma (symptoms similar to serotonin syndrome) have occurred in patients taking phenelzine with dextromethorphan (in overdosage in one case). Three other serious but non-fatal reactions occurred in patients taking dextromethorphan with isocarboxazid or phenelzine.
MAOIs are contraindicated with dextromethorphan.