A Clinical Case of Beta-2 Agonist Induced Hypokalemia

Abstract

Background: Beta-2 adrenergic receptor agonists are extensively used in the management of bronchial asthma and chronic obstructive pulmonary disease (COPD). These agents can cause a variety of systemic adverse effects, most notably hypokalemia, by promoting the intracellular shift of potassium ions. Hypokalemia, defined as a serum potassium level below 3.5 mEq/L, may present with neuromuscular manifestations (e.g., weakness, cramps, paresthesia) and cardiovascular complications, such as arrhythmias and hypotension.

Methods: We present the case of a 4-month-old male with a history of recurrent cough and cold, managed repeatedly with antibiotics and beta-2 agonist nebulizations. Clinical data, laboratory investigations, and imaging studies were assessed to establish a diagnosis. A comprehensive literature review was conducted to explore the pathophysiology, diagnostic approach, and management protocols for beta-2 agonist-induced hypokalemia.

Results: The patient presented with cough, cold, fever of 10 days’ duration, and decreased limb movement over the past 4 days. Examination revealed bilateral wheeze, crepitations, and neuromuscular weakness (power 3/5 in all limbs). Laboratory investigations indicated hypokalemia (serum K: 2.9 mEq/L), with elevated serum calcium levels (11.4 mg/dL) and normal creatine kinase. Imaging studies (chest X-ray) suggested hyperinflated lung fields. The final diagnosis of beta-2 agonist-induced hypokalemia was established after excluding other differential diagnoses such as Guillain–Barré syndrome, spinal muscular atrophy, and electrolyte disturbances like hypomagnesemia.

Conclusion: This case highlights the importance of recognizing beta-2 agonist-induced hypokalemia in pediatric patients receiving frequent nebulizations or oral beta-2 agonist therapy. Early identification, prompt potassium repletion, and discontinuation of the offending agent can prevent severe complications. Clinicians should maintain vigilance for electrolyte imbalances in pediatric populations, especially in those with a history of repeated or high-dose beta-2 agonist use.