Side Effects of Imitrex (Sumatriptan)
Sumatriptan (Imitrex) commonly causes side effects including nausea, warmth, vomiting, vertigo, malaise, headache, injection site reactions (with injectable forms), and chest pressure/heaviness. 1, 2
Common Side Effects
- Neurological effects: Tingling or numbness in fingers or toes, dizziness, drowsiness, weakness, and fatigue 2, 3
- Gastrointestinal effects: Nausea, vomiting, and xerostomia (dry mouth) 1, 2
- Cardiovascular effects: Feelings of warmth, chest pressure and heaviness 1, 2
- Administration site reactions: Pain and redness at injection site (occurs in approximately 40% of patients receiving subcutaneous sumatriptan) 4
- General effects: Malaise, vertigo, and pain/discomfort/stiffness in neck, throat, or jaw 1, 2, 3
Serious Side Effects
Cardiovascular Concerns
- Heart problems: Sumatriptan can cause serious cardiac events including myocardial infarction, which may lead to death 2
- Vasospastic reactions: Changes in color or sensation in fingers and toes (Raynaud's syndrome) 2
- Peripheral vascular ischemia: Symptoms include cramping/pain in legs/hips, heaviness in leg muscles, burning pain in feet/toes, numbness/tingling/weakness in legs, and cold feeling or color changes in extremities 2
Gastrointestinal Ischemic Events
- Sudden or severe stomach pain, stomach pain after meals, weight loss, nausea/vomiting, constipation/diarrhea, bloody diarrhea, and fever 2
Neurological Concerns
- Seizures: Can occur even in patients with no history of seizures 2
- Serotonin syndrome: Particularly when used with antidepressants like SSRIs or SNRIs, symptoms include mental changes, fast heartbeat, blood pressure changes, high body temperature, tight muscles, and trouble walking 2
Other Serious Concerns
- Medication overuse headache: Some people who use too many sumatriptan tablets may experience worsening headaches 2
- Allergic reactions: Hives, swelling of tongue, mouth, or throat 2
Contraindications
Sumatriptan should not be used in patients with:
- Uncontrolled hypertension 5
- Recent use (within 24 hours) of ergotamine-containing medications 5, 2
- History of heart problems or coronary artery disease 1, 2, 4
- Hemiplegic or basilar migraine 1, 2
- Use within 24 hours of another triptan 1, 2
- Impaired hepatic function 1
- Pregnancy (should only be used under strict specialist supervision) 5
Special Considerations
Drug Interactions
- Antidepressants: Caution with SSRIs, SNRIs, TCAs, and MAOIs due to risk of serotonin syndrome 2
- Ergot medications: Do not use within 24 hours of ergotamine or other ergot-type medications 2
Mechanism of Side Effects
- Some side effects like limb heaviness and muscle aches may be related to reduced oxygen storage in peripheral skeletal muscle due to mild vasoconstriction 6
- Chest symptoms (tightness and pressure) occur in 3-5% of patients but are typically not associated with myocardial ischemia in most cases 4, 3
Dosage Considerations
- Do not exceed 200 mg of sumatriptan tablets in a 24-hour period 2
- If headache returns, a second dose can be taken 2 hours after the first tablet 2
- Most adverse events are mild to moderate in intensity, transient, and resolve spontaneously 3
Monitoring and Management
- Patients should track when they have headaches and when they take sumatriptan to discuss effectiveness with their healthcare provider 2
- Due to potential dizziness, weakness, or drowsiness, patients should avoid driving, using machinery, or activities requiring alertness until they know how sumatriptan affects them 2
- The adverse event profile remains stable during long-term treatment and is not affected by frequency of use 3