[Reversible coronary artery spasms associated with cocaine use]. / Reversibel coronairspasme bij cocaïnegebruik.

A 32-year-old man developed coronary artery spasms after using cocaine. He had no significant coronary stenoses. The reversible spasms were diagnosed during heart catheterisation which was carried out because of typical chest pain and electrocardiographic changes. In young adults the use of cocaine increases the risk of a myocardial infarction by a factor of 6.9. Nevertheless, the number of people using cocaine has increased over the past years. The cardiovascular complications of using cocaine have a multifactorial pathogenesis. The treatment of coronary artery spasms may involve a calcium antagonist. Use of cocaine must be kept in mind as a cardiovascular risk factor in a patient presenting with chest pain.

Pharmacological evidence that alpha1-and alpha2-adrenoceptors mediate vasoconstriction of carotid arteriovenous anastomoses in anaesthetized pigs.

Vasoconstriction of carotid arteriovenous anastomoses may be involved in the therapeutic action of acutely acting anti-migraine agents, including the triptans and ergot alkaloids. While 5-HT1B/1D receptors mediate the effect of triptans, ergotamine and dihydroergotamine also interact with alpha-adrenoceptors. In the present study, we investigated the potential role of alpha1- and alpha2-adrenoceptors in mediating vasoconstriction of carotid arteriovenous anastomoses in anaesthetized pigs. Ten minute intracarotid infusions of phenylephrine (1, 3 and 10 microg kg(-1) min(-1)) or BHT 933 (3, 10 and 30 microg kg(-1) min(-1)) produced dose-dependent decreases in total carotid and arteriovenous anastomotic conductances; no changes were observed in the capillary fraction. The carotid vascular effects of phenylephrine and BHT 933 were selectively abolished by prazosin (100 microg kg(-1), i.v.) and rauwolscine (300 microg kg(-1), i.v.), respectively. The responses to phenylephrine and BHT 933 were not affected by the selective 5-HT1B/1D receptor antagonist GR127935 (500 microg kg(-1), i.v.). These results show that both alpha1- and alpha2-adrenoceptors can mediate vasoconstriction of carotid arteriovenous anastomoses in anaesthetized pigs. Since vasoconstrictor activity in this in vivo model is predictive of anti-migraine activity, an agonist activity at particularly the alpha2-adrenoceptor subtypes, in view of their less ubiquitous nature, could provide migraine abortive potential. Thus, the present results may aid further understanding of the mode of action of some current anti-migraine agents and may eventually be helpful in the development of future treatment in migraine.