What is the recommended dosing and administration instructions for sumatriptan (Imitrex) for migraine headaches?

Sumatriptan Dosing and Administration for Migraine

Administer sumatriptan at migraine onset using oral 50-100 mg, subcutaneous 6 mg, or intranasal 5-20 mg, with route selection based on speed of relief needed and patient tolerance for adverse effects. 1

Oral Dosing

• Start with 50-100 mg orally at migraine onset - the 100 mg dose may not provide greater effect than 50 mg but both are superior to 25 mg 2
• If migraine persists after 2 hours or returns after transient improvement, administer a second dose at least 2 hours after the first dose 2
• Maximum daily dose: 200 mg in 24 hours 2
• In patients with mild to moderate hepatic impairment, do not exceed 50 mg as the maximum single dose 2

Subcutaneous Dosing

• Administer 6 mg subcutaneously at migraine onset - this provides the fastest relief, with 70-80% of patients experiencing headache relief within 1 hour 3, 1
• May repeat once after 1 hour if needed 1, 4
• Maximum daily dose: 12 mg per 24 hours 3, 1, 4
• Expect injection site reactions in approximately 30% of patients 3

Intranasal Dosing

• Administer 5-20 mg intranasally (one to two sprays in one nostril) at migraine onset 1
• May repeat after 2 hours if needed 3, 1
• Maximum daily dose: 40 mg per 24 hours 3, 1, 4

Critical Timing and Trial Instructions

• Administer at the onset of migraine symptoms, not during the aura phase 1
• Patients must try sumatriptan for 2-3 headache episodes before abandoning therapy, as response can vary between attacks 3, 4
• Approximately 40% of patients experience headache recurrence within 24 hours, but most respond well to a second dose 3

Combination Therapy for Inadequate Response

• If adequate dose of sumatriptan provides insufficient pain relief, combine with an NSAID or acetaminophen rather than abandoning triptan therapy 3
• If inadequate response persists after dose optimization, switch to another triptan (almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, or zolmitriptan) 3
• For patients with severe nausea or vomiting, use a nonoral triptan formulation with an antiemetic 3

Absolute Contraindications

• Coronary artery disease, previous myocardial infarction, or Prinzmetal angina 1, 2
• Hemiplegic or basilar migraine 3, 1, 2
• Uncontrolled hypertension 1, 2
• Peripheral vascular disease or ischemic bowel disease 2
• History of stroke or transient ischemic attack 2
• Severe hepatic impairment 2
• Pregnancy 3
• Wolff-Parkinson-White syndrome or other cardiac accessory conduction pathway disorders 2

Critical Drug Interactions and Timing

• Do not use within 24 hours of another triptan or ergotamine-containing medication 3, 1, 2
• Mandatory 24-hour washout period between sumatriptan and dihydroergotamine (DHE) in either direction 1
• Do not use concurrently or within 2 weeks of MAO-A inhibitor use 3, 1, 2

Common Adverse Effects

• Chest pressure, heaviness, or warmth occurs in 3-5% of patients but is generally not associated with myocardial ischemia 1
• Other common effects include paresthesia, warm/cold sensation, neck/throat/jaw pain/tightness/pressure, vertigo, nausea, vomiting, and malaise 3, 2
• Evaluate for coronary artery disease in high-risk patients experiencing chest symptoms 2

Important Pitfalls to Avoid

• Do not exceed maximum daily doses as medication overuse headache can develop 2
• Do not dismiss sumatriptan as ineffective after only one migraine attack - efficacy varies between episodes 3, 4
• Do not use for migraine prophylaxis - sumatriptan is for acute treatment only 2
• Safety of treating more than 4 headaches in a 30-day period has not been established 2