Beta blockers Ergot alkaloids

Ergotamine is an ergot alkaloid derivative indicated in the treatment of migraine. Propranolol (a fat-soluble and therefore centrally active beta-blocker) and amitriptyline (tricyclic antidepressant) are used for the prophylaxis of migraine headache. 

Drugs that may be affected by beta blockers include flecainide, gabapentin, haloperidol, hydralazine, phenothiazines, anticoagulants, benzodiazepines, clonidine, disopyramide, epinephrine, ergot alkaloids, lidocaine, nondepolarizing muscle relaxants, prazosin, sulfonylureas, and theophylline. 

Drugs that may affect ergot alkaloids include beta blockers, CYB3A4 inhibitors (see Contraindications), nicotine, and sibutramine. 

Ergot alkaloids interact with beta-blockers, antimigraine drugs, antibacterials, and glycerol nitrate. Concomitant administration with erythromycin causes ergotism.147,148... 

The hypertensive crisis that can follow the withdrawal of clonidine can be accentuated by beta-blockers. It has also been reported that when beta-blockers are used in conjunction with drugs that cause arterial vasoconstriction they can have an additional effect on peripheral perfusion, which can be hazardous. Thus, combining beta-blockers with ergot alkaloids, as has been recommended for migraine, can cause severe peripheral ischemia and even tissue necrosis (408). 

Venter CP, Joubert PH, Buys AC. Severe peripheral ischaemia dmmg concomitant use of beta blockers and ergot alkaloids. BMJ (Clm Res Ed) 1984 289(6440) 288-9. 

Aortic and mitral valvular fibrosis can lead to congestive cardiac failure fibrosis rarely affects the endocardium more extensively (extending into the myocardium) or the pericardium (resulting in constrictive pericarditis). Vasospastic effects can occasionally be as severe in susceptible subjects as with ergotamine especially dangerous are combinations with ergotamine tartrate, as are combinations of ergot alkaloids with beta-blockers (SEDA-9,128). 

Clinically important, potentially hazardous interactions with alcohol, amiodarone, beta-blockers, cimetidine, donidine, digoxin, diltiazem, disopyramide, ephedrine, epinephrine, ergot alkaloids, guanethidine, halothane, isoprenaline, lidocaine, noradrenaline, NSAIDs, phenylephrine, quinidine, reserpine, verapamil... 

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