Phentolamine therapy for cocaine-associated acute coronary syndrome (CAACS)

Abstract

INTRODUCTIONCocaine abuse accounts for over 64,000 ED visits annually, of which more than 50% are chest pain related [1,2]. The differential diagnosis of cocaine-related chest pain is broad and includes acute coronary syndrome (ACS), aortic dissection, pneumothorax, pneumomediastinum, pneumopericardium, and pulmonary infarction [3][4][5][6][7][8]. Diagnostic and treatment strategies are similar to that of other ED patients with chest pain. However, when considering the therapy of CAACS, strategies differ. For cocaine exposure, coronary artery vasoconstriction is mediated by alphaadrenergic stimulation [5]. We are presenting the second published case of CAACS with electrocardiogram (ECG) abnormalities that resolved when the use of an alpha-adrenergic receptor antagonist, phentolamine, was implemented. CASE REPORTA 43-year-old man with a history of depression presented to the emergency department (ED) with a chief complaint of left sided chest pain that began 1 hour after insufflating cocaine. The pain was described as an intense ache that was a "10 out of 10" in terms of its intensity, and it radiated to his left shoulder. He attempted to alleviate his symptoms by drinking ethanol to "bring him down" but this was unsuccessful at relieving the pain. A similar event happened two weeks prior, also during cocaine use, and the patient was admitted to a hospital and diagnosed with CAACS. His evaluation (including serum troponin levels over a 24-hour period, echocardiogram, and exercise stress test) was normal. He was discharged on aspirin, diltiazem, nitroglycerin, and referred to a Case report: We are reporting on the treatment of a patient with cocaine-associated acute coronary syndrome (CAACS) who did not benefit from standard therapy, but who eventually responded positively to phentolamine, an alpha-adrenergic receptor antagonist.Discussion: This report should encourage physicians to add phentolamine to their pharmacotherapeutic armamentarium in the treatment of CAACS.

Treatment of patients with cocaine‐induced arrhythmias: bringing the bench to the bedside

“…In a similar investigation, a-adrenergic blockade was also effective, but b-adrenergic blockade was not [67]. In humans, the benefits of a-adrenergic blockade (phentolamine) have been demonstrated experimentally with regard to reversal of cocaine-induced coronary vasoconstriction [68] and clinically with regard to reversal of acute coronary syndrome [69,70], but not with regard to arrhythmias. As mentioned previously, data suggest safety and efficacy of lidocaine in humans [29], contraindications exist for b-adrenergic antagonists, and both type IA and IC antiarrhythmic agents.…”

Cardiovascular consequences of cocaine use

“…The ability of phentolamine to reverse cocaine-induced vasoconstriction during experimental cardiac catheterization was first described in a small clinical trial in 1989 [23]. Since that time, two case reports in the literature describe successful phentolamine treatment of patients with cocaine-associated acute coronary syndromes who did not respond to standard therapy [88,89]. Despite the potential utility of phentolamine in the case of cocaine-associated cardiac dysfunction, it is used infrequently in the clinical setting, and further studies are warranted.…”

Nonparallel cutaneous microcirculatory responses to pharmacologic alterations of systemic arterial pressure in rats

“…It is acceptable to reduce the pharmacological interaction according to the half-life of each agent. 18,19,23 In conclusion, it seems better to use nitric oxide donor instead of a-adrenoceptor blocker to correct high-blood pressure after reconstructive microsurgery. On the other hand, in hypotension situations, volume expansion instead of vasoconstrictor is a better choice to protect regional perfusion.…”

“…Systemic arterial pressure was altered by intravenous infusion of 1) saline, vehicle control, 1 ml/kg; 2) sodium nitroprusside, a nitric oxide (NO) donor with a half-life of approximately 90 seconds, 10 lg/ml, 12 ml/hour 18 ; 3) phentolamine, an a-adrenoceptor antagonist with a halflife of approximately 18 minutes, 19 2.5 mg/kg [20][21][22] ; and 4) phenylephrine, an a-adrenoceptor agonist with a halflife of approximately 4.8-17.6 minutes, 23 10 lg/ml, 12 ml/hour 24 for 10 minutes in random sequences. Twenty to thirty minutes were waited before the administration of the following drugs to wash out the previous pharmacologic effects.…”