What is the recommended adult dosage of sumatriptan (Imitrex) for migraine?

Adult Dosage of Sumatriptan for Migraine

For oral sumatriptan, start with 50 mg or 100 mg as the initial dose, as these provide superior efficacy compared to 25 mg, with the 50 mg dose offering the best balance of effectiveness and tolerability. 1

Oral Dosing Recommendations

Initial Dose Selection

• The FDA-approved oral doses are 25 mg, 50 mg, or 100 mg 1
• The 50 mg and 100 mg doses provide greater efficacy than 25 mg 1
• The 100 mg dose may not provide significantly greater effect than 50 mg, but carries higher risk of adverse reactions 1
• Start with 50 mg for optimal efficacy-to-tolerability ratio, or use 100 mg for patients requiring maximum efficacy 2

Repeat Dosing

• If migraine has not resolved by 2 hours or returns after transient improvement, a second dose may be administered at least 2 hours after the first dose 1
• Maximum daily dose is 200 mg in a 24-hour period 1

Trial Period Before Switching

• Patients should try sumatriptan for 2-3 headache episodes before determining effectiveness 3, 4
• If inadequate response after dose optimization, consider switching to another triptan (almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, or zolmitriptan) 3

Alternative Routes of Administration

Subcutaneous Administration

• Dose: 6 mg, can be repeated after 1 hour 3, 4
• Maximum daily dose: 12 mg per 24 hours 3, 4
• Most effective route with 59% achieving complete pain relief at 2 hours (versus 15% with placebo) 5
• Injection site reactions occur in approximately 30% of patients 3, 4

Intranasal Administration

• Dose: 5-10 mg (one to two sprays) in one nostril, can be repeated after 2 hours 3, 4
• Maximum daily dose: 40 mg per day 3, 4
• The 20 mg dose is most effective for this route 5

Combination Therapy Strategy

• If adequate dose of sumatriptan alone provides insufficient pain relief, combine with an NSAID or acetaminophen 3
• This combination approach is recommended by the American College of Physicians when monotherapy fails 3

Special Populations

Hepatic Impairment

• Maximum single dose should not exceed 50 mg in patients with mild to moderate hepatic impairment 1

Critical Contraindications

• Do not use with ergotamine, MAOIs, or within 24 hours of another triptan 3, 4
• Contraindicated in hemiplegic or basilar migraine, pregnancy, impaired hepatic function, or coronary artery disease 3, 4

Common Adverse Effects

• Nausea, warmth, vomiting, vertigo, malaise, headache, chest pressure and heaviness 3
• Adverse events more common with 100 mg dose (number-needed-to-harm = 7.1) compared to lower doses 6

Important Clinical Pitfalls

• Consider using a nonoral triptan with an antiemetic in patients with severe nausea or vomiting 3
• Do not treat more than 4 headaches in a 30-day period, as safety beyond this has not been established 1
• After initial subcutaneous sumatriptan injection, additional oral doses (up to 100 mg/day) may be given with at least 2-hour intervals 1