Q: Why is vasopressin preferable over epinephrine in cardio-pulmonary arrest due to cocaine overdose?
Answer: Epinephrine, like cocaine, has alpha-adrenergic effects. Because of this similarity in the cardiovascular effects, the administration of epinephrine to a patient who arrests in a hyperadrenergic state has been like "pouring gasoline over fire."
Moreover, cocaine prevents the reuptake of exogenously administered epinephrine. Therefore, if epinephrine is used, AHA Guidelines recommend that high-dose epinephrine should be avoided and that the interval for its administration be increased.
Vasopressin offers considerable advantages over epinephrine in cardiac arrest secondary to cocaine toxicity. The hyperadrenergic state caused by cocaine increases myocardial oxygen demand, and vasopressin increases coronary blood flow and thereby myocardial oxygen availability.
Also, cocaine toxicity causes acidosis and epinephrine loses much of its effectiveness in an acidotic environment, whereas vasopressin demonstrates good efficacy even with severe acidosis.
#hemodynamic
#toxicity
Recommended readings:
1. Sofuoglu M, Nelson D, Babb DA, Hatsukami DK. Intravenous cocaine increases plasma epinephrine and norepinephrine in humans. Pharmacol Biochem Behav. 2001 Mar;68(3):455-9. doi: 10.1016/s0091-3057(01)00482-8. PMID: 11325399.
2. Richards JR, Garber D, Laurin EG, Albertson TE, Derlet RW, Amsterdam EA, Olson KR, Ramoska EA, Lange RA. Treatment of cocaine cardiovascular toxicity: a systematic review. Clin Toxicol (Phila). 2016 Jun;54(5):345-64. doi: 10.3109/15563650.2016.1142090. Epub 2016 Feb 26. PMID: 26919414.
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