What is the recommended dose of sumatriptan (Imitrex) for treating migraine headaches?

Sumatriptan Dosing for Migraine Treatment

For oral sumatriptan, start with 50-100 mg at migraine onset, which can be repeated after 2 hours if needed, with a maximum daily dose of 200 mg per 24 hours. 1

Dosing by Route of Administration

Oral Administration

• The FDA-approved oral dose is 25 mg, 50 mg, or 100 mg, with 50 mg and 100 mg providing greater effect 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
• If the migraine has not resolved by 2 hours or returns after transient improvement, a second dose may be given at least 2 hours after the first dose 1
• Maximum daily dose is 200 mg in a 24-hour period 1

Subcutaneous Administration

• Administer 6 mg subcutaneously at migraine onset, which can be repeated once after 1 hour if needed 2, 3
• Maximum daily dose is 12 mg per 24 hours 2, 3
• This route provides the fastest relief, with 70-80% of patients experiencing relief within 1 hour 2
• Injection site reactions occur in approximately 30% of patients 2

Intranasal Administration

• Administer 5-20 mg intranasally, which can be repeated after 2 hours 3
• Maximum daily dose is 40 mg per 24 hours 2, 3

Route Selection Strategy

Choose the route based on speed of relief needed and patient tolerance for adverse effects 3:

• Subcutaneous provides fastest relief (within 1 hour) but has highest rate of injection site reactions 2
• Oral is better tolerated but takes 2-4 hours for relief 1
• Intranasal offers intermediate speed of onset 3

Special Dosing Considerations

Hepatic Impairment

• In mild to moderate hepatic impairment, the maximum single oral dose should not exceed 50 mg 1

Trial Period

• Patients should try sumatriptan for 2-3 migraine episodes before determining effectiveness 2
• If one triptan is ineffective, consider trying a different triptan 2

Frequency Limitations

• The safety of treating more than 4 headaches in a 30-day period has not been established 1
• Monitor for medication overuse, which may lead to rebound headaches 2

Critical Contraindications

Do not administer sumatriptan in the following situations 2, 3:

• Concurrent use with ergotamine derivatives or within 24 hours of another triptan 2, 3
• Current MAOI use 2, 3
• Coronary artery disease, previous myocardial infarction, or Prinzmetal angina 3
• Hemiplegic or basilar migraine 2, 3
• Uncontrolled hypertension 3
• Pregnancy 2
• Impaired hepatic function (or use reduced dose) 2, 1

Common Adverse Effects

• Chest pressure, heaviness, or warmth occurs in 3-5% of patients 3
• Subcutaneous administration causes injection site reactions in approximately 30% 2
• Oral administration may cause nausea, vomiting, malaise, fatigue, and dizziness 3

Practical Algorithm

1. Start with oral 50-100 mg for most patients (better tolerability profile) 1
2. Use subcutaneous 6 mg when rapid relief is essential (severe attacks, significant disability) 2, 3
3. Repeat dosing only after appropriate interval: 2 hours for oral, 1 hour for subcutaneous 2, 1
4. Do not exceed maximum daily doses: 200 mg oral, 12 mg subcutaneous, 40 mg intranasal 2, 1