Tegaserod-Induced Myocardial Infarction: Case Report and Hypothesis

Serotonin (5-hydroxytryptamine [5-HT])₁ receptor agonists, such as those used for treating migraine, can cause coronary artery contraction, coronary spasm, and even myocardial infarction. Tegaserod maleate is a relatively new 5-HT₄ receptor agonist with moderate affinity for the 5-HT₁ receptor. Currently, it is approved only for treatment of irritable bowel syndrome in women who have constipation as the primary symptom. However, it is also being administered as a promotility agent in patients with gastroparesis. Since tegaserod has affinity for the 5-HT₁ receptor, it is plausible that tegaserod could cause the same types of cardiovascular adverse events seen with agents prescribed for management of migraine. We report the first case of a man who experienced a myocardial infarction after receiving only two 6-mg doses of tegaserod; we also provide a hypothesis regarding this event. When considering prescribing a drug with 5-HT₁ receptor agonist activity, clinicians should review the patient's medical history specifically for the presence of underlying cardiovascular risk factors.