Surprise Unopposed Alpha Stimulation in a Patient Receiving Labetalol

Introduction/Background:

Historically, using beta blockers in patients with active cocaine use was considered taboo due to concerns about unopposed alpha stimulation, which can present life-threatening complications. While emerging studies suggest beta blockers' safety in cocaine users, this risk remains significant. Beta blockers are effective in managing hypertension and tachycardia from cocaine use but can worsen the clinical course in some patients.

Description:

A 42-year-old male presented to the Emergency Department with severe left shoulder pain radiating down the arm after a night of heavy alcohol use. His blood pressure was 175/119, and his heart rate was 114. He was moved quickly from triage due to his discomfort and agitation. He received 20 mg IV Labetalol before a CT scan. Subsequently, he became tachycardic, hypoxic, and his blood pressure increased. The patient was started on supplemental O2 and admitted for further management. A urine drug screen revealed cocaine use, which he either did not disclose or was unaware of. His initial complaint of left arm pain was found to be a chronic issue. A chest X-ray and CT scan suggested pulmonary edema. Labetalol was discontinued, and clonidine was started to manage both hypertension and post-cocaine anxiety. He was also restarted on his prior medications, amlodipine and lisinopril-hydrochlorothiazide, and given Ativan for additional anxiolytic benefits. By the next morning, heart rate normalized, and he was weaned off supplemental oxygen. With his blood pressure under control, he was discharged home with close follow-up with his primary care physician.

Discussion:

This case illustrates that while the interaction between cocaine and beta blockers may be rare, it is far from theoretical. Cocaine use is unfortunately common, with resultant nonischemic cardiomyopathy (NICM), hypertensive emergencies, and frequently presenting tachycardia. High clinical suspicion and risk stratification should be exercised before using beta blockers to prevent unintended negative outcomes.