Sumatriptan (Imitrex) Dosing for Migraine Headaches
For acute migraine treatment, sumatriptan tablets are recommended at doses of 25 mg, 50 mg, or 100 mg, with 50 mg offering the optimal balance between efficacy and tolerability for most patients. 1, 2
Oral Administration
- Initial recommended dose: 25-100 mg at migraine onset 1
- 50 mg and 100 mg doses may provide greater effect than 25 mg 1
- Maximum single dose: 100 mg 1
- If migraine persists after 2 hours or returns after initial improvement, a second dose may be administered (at least 2 hours after first dose) 1
- Maximum daily dose: 200 mg in a 24-hour period 1
- For patients with mild to moderate hepatic impairment, maximum single dose should not exceed 50 mg 1
Subcutaneous Administration
- Recommended dose: 6 mg SC, which can be repeated after one hour 3
- Maximum daily dose: 12 mg per 24 hours 3, 4
Intranasal Administration
- Recommended dose: 5-10 mg (1-2 sprays) in one nostril 3, 4
- May be repeated after 2 hours 3, 4
- Maximum daily dose: 40 mg per day 3, 4
Efficacy Considerations
- Clinical trials show that 50-56% of patients achieve headache relief within 2 hours with oral sumatriptan (vs. 26% with placebo) 5
- By 4 hours, 68-71% of patients achieve headache relief (vs. 38% with placebo) 5
- Evidence suggests doses above 50 mg do not provide significantly greater effect than 50 mg 1, 2
- Numbers-needed-to-treat (NNTs) for pain-free response at 2 hours: 5.1 for 100 mg dose and 7.5 for 25 mg dose 6
- For headache relief at 2 hours, NNTs were 3.4,3.2, and 3.4 for sumatriptan 100 mg, 50 mg, and 25 mg, respectively 6
Important Contraindications
- Ergotamine or ergotamine derivatives (within 24 hours) 3, 4
- MAOIs (monoamine oxidase inhibitors) 3, 4
- Use within 24 hours of another triptan 3, 4
- Hemiplegic or basilar migraine 3, 4
- Pregnancy or impaired hepatic function 3, 4
- Coronary artery disease, previous myocardial infarction, or Prinzmetal (variant) angina 3, 7
- Uncontrolled hypertension 7
Common Adverse Effects
- Oral administration: nausea, vomiting, malaise, fatigue, and dizziness 7, 8
- Subcutaneous administration: injection site reactions (in approximately 30% of patients), chest pressure and heaviness 3, 7
- Chest symptoms (tightness and pressure) occur in 3-5% of patients 7, 8
- Adverse events are more common with 100 mg than with placebo (NNH = 7.1) 6
Clinical Pearls
- Approximately 40% of patients who initially respond to sumatriptan may experience headache recurrence within 24 hours, which can be effectively treated with another dose 7, 8
- Sumatriptan should not be given during migraine aura 7
- The efficacy of sumatriptan is unaffected by presence of aura, duration of headache prior to treatment, gender, age, weight, relationship to menses, or concomitant use of common migraine prophylactic drugs 1
- Patients should try sumatriptan for 2-3 headache episodes before abandoning this therapy 4