What is the recommended sumatriptan (Imitrex) regimen for a patient with migraines, considering their medical history and potential cardiovascular risk factors?

Sumatriptan Regimen for Migraines

Route Selection and Dosing

For moderate to severe migraine attacks, start with oral sumatriptan 50-100 mg at headache onset, repeating once after 2 hours if needed (maximum 200 mg/24 hours), or use subcutaneous sumatriptan 6 mg for fastest relief (maximum 12 mg/24 hours). 1, 2

Oral Sumatriptan Dosing

• Initial dose: 50-100 mg at migraine onset when pain is still mild for optimal effectiveness 1, 2
• May repeat once after 2 hours if headache persists or returns 1
• Maximum daily dose: 200 mg in 24 hours 1, 2
• Efficacy: 50-73% of patients achieve headache relief within 2 hours with 100 mg dose 3, 4
• The 100 mg dose provides pain-free response in approximately 1 in 5 patients (NNT 5.1), while 50 mg and 25 mg doses show similar headache relief rates 3

Subcutaneous Sumatriptan Dosing

• Initial dose: 6 mg at migraine onset 1, 2
• May repeat once after 1 hour if needed 1, 2
• Maximum daily dose: 12 mg in 24 hours 1, 2
• Highest efficacy: 70-82% response rate within 15 minutes, with 59% achieving complete pain relief by 2 hours 1, 5, 6
• Use subcutaneous route for severe attacks, rapid progression to peak intensity, or significant nausea/vomiting 7

Intranasal Sumatriptan Dosing

• Initial dose: 5-20 mg (one to two sprays) in one nostril 1, 2
• May repeat after 2 hours 1, 2
• Maximum daily dose: 40 mg in 24 hours 1, 2
• Particularly useful when significant nausea or vomiting is present 7

Combination Therapy for Enhanced Efficacy

Add an NSAID (naproxen 500 mg, ibuprofen 400-800 mg, or diclofenac) to sumatriptan rather than increasing triptan dose or frequency if initial response is inadequate. 7, 8

• Combination therapy of triptan plus NSAID is superior to either agent alone, with 130 more patients per 1000 achieving sustained pain relief at 48 hours 7
• Add the NSAID at the same time as sumatriptan, not sequentially 7
• This combination addresses the 40% of patients who experience headache recurrence within 8-12 hours 7, 5

Critical Frequency Limitation

Strictly limit sumatriptan use to no more than 10 days per month (approximately 2 days per week) to prevent medication-overuse headache. 7, 2, 9

• Triptans used ≥10 days per month can cause rebound headaches and paradoxically increase headache frequency 7, 8, 9
• If requiring acute treatment more than twice weekly, initiate preventive therapy immediately 7

Managing Inadequate Response

If sumatriptan fails after 2-3 separate headache episodes, switch to a different triptan (rizatriptan, eletriptan, zolmitriptan, or naratriptan) as failure of one triptan does not predict failure of others. 7, 8

• Rizatriptan 10 mg reaches peak concentration in 60-90 minutes, making it the fastest oral triptan 7
• Eletriptan 40 mg and zolmitriptan 2.5-5 mg are reportedly more effective with fewer adverse reactions than sumatriptan 7
• If all triptans fail after adequate trials, escalate to CGRP antagonists (ubrogepant 50-100 mg or rimegepant) 7, 8

Absolute Contraindications

Do not administer sumatriptan to patients with: 1, 2, 9

• Coronary artery disease, previous myocardial infarction, or Prinzmetal's angina 1, 2, 9
• Uncontrolled hypertension 1, 2, 9
• History of stroke or transient ischemic attack 9
• Hemiplegic or basilar migraine 1, 2, 9
• Use of ergotamine, dihydroergotamine, or another triptan within 24 hours 1, 2, 9
• Current MAOI use 1, 2
• Wolff-Parkinson-White syndrome or other cardiac accessory conduction pathway disorders 9

Cardiovascular Risk Assessment

For triptan-naive patients with multiple cardiovascular risk factors (increased age, diabetes, hypertension, smoking, obesity, strong family history of CAD), perform cardiovascular evaluation before prescribing sumatriptan. 9

• If cardiovascular evaluation is negative but multiple risk factors present, consider administering first dose in medically supervised setting with ECG immediately following administration 9
• Consider periodic cardiovascular evaluation in intermittent long-term users with risk factors 9

Common Adverse Effects

Warn patients about expected sensations that are usually non-cardiac in origin: 1, 9

• Chest pressure, heaviness, or tightness (3-5% of patients) 2, 9
• Throat, neck, or jaw pain/tightness/pressure 9
• Injection site reactions (10-40% with subcutaneous route) 10
• Nausea, warmth, malaise, fatigue, dizziness 1, 10

However, perform cardiac evaluation if these symptoms occur in patients at high cardiac risk 9

Critical Pitfalls to Avoid

• Never increase sumatriptan dose or frequency beyond recommended limits—instead add an NSAID or switch to a different triptan 7, 8
• Never use opioids or butalbital-containing compounds for migraine treatment, as they lead to dependency, rebound headaches, and loss of efficacy 7, 8
• Never administer sumatriptan during the migraine aura phase—wait until headache begins 6
• Never combine sumatriptan with ergotamines or other triptans within 24 hours due to additive vasoconstrictive effects 1, 2, 9
• Do not allow patients to establish patterns of frequent use—transition to preventive therapy when acute treatment is needed more than twice weekly 7