Adrenoceptors migraine

There are various neurologic disorders which can be treated with jS-blockers like migraine, certain forms of tremor and alcohol withdrawal syndrome. Somatic manifestations of anxiety respond well to /3-adrenoceptor blockade. jS-Blockers with a selectivity for the jSi-subtype might be useful to avoid extracardial side effects. 

Blockade of /32-adrenoceptors by non-selective /3-blockers causes side-effects such as bronchoconstriction, vasoconstriction and hypoglycaemia. /32-Adrenoceptor blockade is sometimes used in the treatment of migraine or particular forms of tremor. 

Ergotamine Mixed partial agonist effects at 5-HT2 and (X adrenoceptors Causes marked smooth muscle contraction but blocks cx-agonist vasoconstriction Migraine and cluster headache Oral, parenteral duration 12-24 h Toxicity Prolonged vasospasm causing gangrene uterine spasm... 

Ergonovine Mixed partial agonist effects at 5-HT2 and tx adrenoceptors Same as ergotamine some selectivity for uterine smooth muscle Postpartum bleeding migraine headache Oral, parenteral (methylergonovine) duration 2-4 h Toxicity Same as ergotamine... 

A 34-year-old woman had acute congestive heart failure 12 hours after administration of dexamethasone 16 mg for an atypical migraine (29). The authors postulated that the acute episode had been induced by the dexamethasone, which increased the production of adrenaline, causing beta2-adrenoceptor stimulation, peripheral vasodilatation, and congestive heart failure. 

For prevention of migraines, the following types of drug can be used /3-adrenoceptor antagonists, serotonin antagonists and tricyclic antidepressants. 

Ergotamine constricts all peripheral arteries (an effect potentiated by concomitant 3-adrenoceptor block), not just those affected by the migraine process. Due to tissue binding, its effect on arteries persists as long as 24 h and repeated doses lead to cumulative effects long outlasting the migraine attack. 

Isometheptene, used in the treatment of migraine, is an indirect sympathomimetic with a tyramine-like action and is also an agonist at alpha-adrenoceptors. 

Ergots acts as partial agonists at both alpha adrenoceptors and 5HT2 receptors in the vasculature and possibly in the CNS. Vasoconstrictive actions to decrease pulsation in cerebral vessels may be relevant to acute actions of ergotamine during migraine attack. 

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