Which of the following are potential side effects of sumatriptan?

• A. Dizziness, drowsiness, fatigue
• B. GI distress, bradycardia
• C. Embolism, angioedema
• D. Dizziness, drowsiness, fatigue, GI distress, bradycardia, embolism, angioedema

Answer: (D)

Sumatriptan works by activating 5-HT1B/1D receptors, which narrows cranial blood vessels and reduces release of vasoactive peptides to abort migraine. That vascular constriction, along with central nervous system and gastrointestinal receptor interactions, can produce a range of adverse effects. The common ones—dizziness, drowsiness, and fatigue—stem from CNS effects and overall sedation. GI distress like nausea or upset stomach comes from direct effects on the gut. Cardiac effects such as bradycardia can occur due to reflex changes or direct effects on cardiac tissue, and in people with vascular disease it can provoke coronary vasospasm with potential angina or ischemia. Hypersensitivity reactions can lead to angioedema, and although rare, some individuals may experience thromboembolic events due to extreme vasoconstriction. Because of these possibilities, all of the listed effects can be associated with sumatriptan.