Over-the-counter preparations for weight loss have become very popular in this country during the last several years. Most of these preparations are combination stimulants containing phenylpropanolamine, ephedrine, and caffeine. They are widely advertised, readily available, and have become a major item for adolescent drug abuse.
All of these substances have potent and direct adrenergic effects and catecholamine-releasing actions. Hypertension, cerebral hemorrhage, and psychosis have all been associated with use of phenylpropanolamine. Caffeine has been reported to cause ventricular arrhythmias, including ventricular tachycardia. There is a possibility that simultaneous ingestion of all of these drugs could increase the risk of toxicity from each.
Propanolol is the treatment of choice for toxicity manifested by moderate symptomatic hypertension plus atrial or ventricular arrhythmias.