Reduced compensatory CV reactions in case of shock or hypotension due to floctafenine; volatile halogenated anaesth; iodine contrast media. Additive bradycardiac effects w/ sultopride. Inadvisable combination w/ Ca antagonists & amiodarone. May cause Torsades de pointes w/ class IA (eg, quinidine, hydroquinidine, disopyramide) & class III (amiodarone, dofetilide, sotalol) antiarrhythmics; phenothiazine neuroleptics (eg, chlorpromazine, cyamemazine, levopromazine, thioridazine), benzamides (eg, amisulpride, sulpride, tiapride), butyrophenone (eg, droperidol, haloperidol), other neuroleptics (eg, pimozide), & other medicines (eg, cisapride, diphemanil, erythromycin IV, halofantrine, mizolastine, moxifloxacin, pentamidine, spiramycin IV, vincamine IV). Contractility, automatism & conduction disorders w/ propafenone. Increased anti-hypertensive effect w/ baclofen. May mask hypoglycaemic symptoms when given w/ insulin, sulfonylurea, hypoglycaemic agents. Risk of excessive bradycardia w/ anticholinesterase agents (eg, ambenomium, donepezil, galantamine, neostigmine, pyridostigmine, rivastigmine, tacrine). Sudden w/drawal of centrally-acting antihypertensives may increase BP. Increased plasma level of lidocaine. Reduced antihypertensive effect w/ NSAID. Increased anti-hypertensive effect & risk of orthostatic hypotension w/ imipramine antidepressants; neuroleptics. Diminished antihypertensive effect w/ corticosteroid; tetracosactide. Risk of bradycardia w/ mefloquine. Increased antihypertensive effect w/ dipyridamole IV; α-blockers (eg, alfuzocin, doxazosin, prazosin, tamsulosin, terazosin).