Related Experiment Video
Updated: Aug 14, 2026

Methods for ECG Evaluation of Indicators of Cardiac Risk, and Susceptibility to Aconitine-induced Arrhythmias in Rats Following Status Epilepticus
Published on: April 5, 2011
Over-the-counter sympathomimetics: a risk factor for cardiac arrhythmias in pregnancy
1Department of Internal Medicine, Greater Baltimore Medical Center, MD 21204, USA.
Abstract:
More than 170 over-the-counter (OTC) preparations contain a sympathomimetic agent as the active ingredient. Nonprescription medicines are consumed commonly in our society. Phenylpropanolamine, an alpha-adrenergic agonist as well as a popular decongestant, is consumed at a massive volume of 5 billion doses annually. Over-the-counter sympathomimetics have been reported to cause hypertension and arrhythmias. Despite the ability to cause these potentially serious adverse effects and the high-volume consumption of these agents, the medical literature until recently has been scant in reporting adverse events. We report symptomatic ventricular arrhythmia and presyncope in a 36-year-old pregnant woman who consumed relatively high doses of two OTC cold remedies simultaneously. Increased physician awareness of the potential side effects associated with OTC sympathomimetics as well as improved level of patient education are needed. Finally, we support the calls for more prominent warning labels on some selected OTC preparations, including OTC sympathomimetics.
Related Concept Videos
Adrenergic Agonists: Direct-Acting Agents
These agents can be classified...
Adrenergic Agonists: Therapeutic Classification
Vasopressor or pressor agents: They increase blood pressure and function as cardiac stimulants. Examples include endogenous catecholamines (norepinephrine and dopamine) and synthetic agents (phenylephrine).
Bronchodilators: β2-agonists can relax bronchial muscles and widen airways. They are commonly used for treating obstructive pulmonary...
Adrenergic Antagonists: ɑ and β-Receptor Blockers
Mechanism of Cardiac Arrhythmias
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers
Upper Respiratory Drugs: Antitussives, Expectorants, and Mucolytics
Antitussives include codeine, dextromethorphan (Robitussin), and benzonatate (Tessalon). Codeine and dextromethorphan exert their effects centrally by suppressing the cough reflex center in the medulla. Benzonatate operates peripherally within the respiratory tract by anesthetizing...

