Class I & III antiarrhythmics; verapamil, nifedipine; centrally-acting antihypertensives, topical β-blockers, parasympathomimetics, insulin or oral antidiabetics, anesth, cardiac glycosides, NSAIDs, β-sympathomimetics; sympathomimetics that activate both β- & α-adrenoceptors; TCAs, barbiturates, phenothiazines; mefloquine, MAOIs.