What is Relpax for Migraine?
Relpax (eletriptan) is a prescription triptan medication—a selective serotonin 5-HT1B/1D receptor agonist—used to treat acute moderate to severe migraine attacks in adults, not to prevent them. 1
Mechanism of Action
Relpax works by reducing swelling of blood vessels surrounding the brain and blocking the release of pain-causing substances from nerve endings. This dual action addresses both the vascular changes and neurogenic inflammation associated with migraine attacks, providing relief from headache pain and associated symptoms like nausea, photophobia, and phonophobia. 1
Clinical Use and Positioning
When to Use Relpax
According to the most recent 2025 American College of Physicians guidelines, eletriptan should be added to an NSAID (or acetaminophen when NSAIDs are contraindicated) when patients fail to achieve sufficient pain relief from an adequate dose of NSAID or acetaminophen alone. 2
The treatment algorithm follows this sequence:
- First-line: Start with NSAIDs or acetaminophen at appropriate doses
- Second-line: Add a triptan (like eletriptan) to the NSAID or acetaminophen for combination therapy
- Alternative: Consider CGRP antagonists or ergots only if combination triptan therapy fails or is not tolerated 2
Dosing and Administration
Relpax is available in 20 mg and 40 mg tablets. 1
Key dosing instructions:
- Take one tablet as soon as migraine symptoms begin
- If headache improves but returns after 2 hours, a second tablet may be taken
- Do not take a second tablet if the first provided no relief—consult your doctor instead
- Maximum: Do not exceed recommended dosing within 24 hours 1
Efficacy Profile
Eletriptan demonstrates robust efficacy with rapid onset:
- 2-hour headache response rates: 47-67% (compared to 22% with placebo) 1, 3
- Pain-free at 2 hours: 14-27% (compared to 4% with placebo) 3
- Onset of action: As early as 30 minutes after administration 4, 5
- Sustained pain-free response: 10-20% (compared to 3% with placebo) 3
In comparative studies, eletriptan 40-80 mg showed superior efficacy to sumatriptan 50-100 mg for most endpoints and was consistently superior to ergotamine/caffeine combinations. 4, 5, 6 Among triptans, eletriptan tablets rank among the most favorable options alongside rizatriptan ODT, zolmitriptan ODT, and sumatriptan subcutaneous injection. 7
Important Contraindications and Warnings
Do NOT use Relpax if you have: 1
- Uncontrolled high blood pressure
- Heart disease or history of heart disease
- Hemiplegic or basilar migraine
- Stroke or circulation problems
- Serious liver problems
- Taken other triptans, ergotamines, or similar medications within the last 24 hours
- Taken certain CYP3A4 inhibitors (ketoconazole, itraconazole, clarithromycin, ritonavir, nelfinavir) within 72 hours
Critical Drug Interactions
Serotonin syndrome risk: When combining Relpax with SSRIs (like Prozac, Zoloft, Lexapro) or SNRIs (like Cymbalta, Effexor), there is a risk of serotonin syndrome—a potentially serious condition. Inform your doctor if you take these medications. 1
Common Pitfalls to Avoid
Medication Overuse Headache
The threshold for medication overuse headache with triptans is ≥10 days per month (compared to ≥15 days for NSAIDs). 2 Patients using Relpax frequently should be evaluated for preventive migraine therapy rather than increasing acute medication use.
Timing of Treatment
Counsel patients to begin treatment as soon as possible after migraine onset using combination therapy (triptan with NSAID or acetaminophen) to improve efficacy. 2 Waiting until pain is severe reduces treatment effectiveness.
Not for Prevention
Relpax is indicated only for acute treatment of migraine attacks, not for prophylactic therapy or management of hemiplegic/basilar migraine. 1 If migraines occur frequently or acute treatment is inadequate, preventive medications should be considered. 2
Safety and Tolerability
Eletriptan is generally well tolerated with adverse events that are typically mild, moderate, and transient. 5, 8 The 20 mg dose has an adverse event profile comparable to placebo. 3 Common side effects include asthenia (weakness) and nausea, occurring in ≤10% of patients. 9
Special populations: In people of childbearing potential and those who are pregnant or breastfeeding, discuss the risks of pharmacologic treatments during pregnancy and lactation. 2