Relpax Dosing for Acute Migraine
The recommended starting dose of Relpax (eletriptan) is 40 mg orally at the onset of migraine, with a maximum single dose of 40 mg and a maximum daily dose of 80 mg. 1
Standard Adult Dosing
Initial dose: 20 mg or 40 mg orally when migraine begins. The 40 mg dose is more effective than 20 mg and should be the preferred starting dose for most patients 1. While an 80 mg dose shows efficacy, it carries significantly higher adverse event rates and is not recommended as a first-line dose 1.
Repeat dosing: If headache improves but returns, a second dose may be taken at least 2 hours after the initial dose 1. However, if the initial dose is completely ineffective, do not take a second dose for the same attack—controlled trials show no benefit 1.
Maximum daily dose: 80 mg total per day 1.
Frequency limitation: The safety of treating more than 3 headaches in a 30-day period has not been established 1.
Special Populations
Hepatic Impairment
- Mild to moderate impairment: No dose adjustment necessary 1
- Severe hepatic impairment: Contraindicated—do not use Relpax, as the effect on eletriptan metabolism was not evaluated 1
Renal Impairment
The FDA label does not specify dose adjustments for renal impairment 1. However, triptans can generally be used selectively in renal disease, often with dose adjustments 2.
Elderly Patients
The FDA label does not provide specific dosing modifications for elderly patients 1. Standard adult dosing applies unless other comorbidities necessitate caution.
Adolescents
Relpax is not FDA-approved for adolescents. The pediatric guideline recommends rizatriptan (a different triptan) for adolescents, not eletriptan 3. If considering triptan therapy in adolescents aged 12-17, use rizatriptan 5 mg orally disintegrating tablet, sumatriptan nasal spray, zolmitriptan nasal spray, or almotriptan oral 3.
Critical Drug Interactions
Absolute contraindication: Do not use Relpax within 72 hours of potent CYP3A4 inhibitors including 1:
- Ketoconazole
- Itraconazole
- Nefazodone
- Troleandomycin
- Clarithromycin
- Ritonavir
- Nelfinavir
Eletriptan is metabolized by CYP3A4, and concurrent use with these inhibitors dramatically increases drug exposure and cardiovascular risk 1.
Clinical Context from Guidelines
The 2025 ACP guideline positions triptans as add-on therapy to NSAIDs or acetaminophen for moderate to severe migraine 4. Start with an adequate dose of NSAID or acetaminophen first; if insufficient pain relief occurs, add a triptan to the NSAID (or to acetaminophen if NSAIDs are contraindicated) 4.
Choice among specific triptans (including eletriptan/Relpax) should be individualized based on route of administration preference and cost 4. For patients with severe nausea or vomiting, consider non-oral triptan formulations with an antiemetic 4.
Common Pitfalls
- Medication overuse headache: Avoid using Relpax ≥10 days per month; this threshold applies to triptans and can lead to medication overuse headache 4
- Ineffective second dose: Do not take a second dose if the first dose provided no benefit whatsoever for that specific attack 1
- CYP3A4 interactions: Always screen for potent CYP3A4 inhibitors before prescribing—the 72-hour washout period is mandatory 1
- Pregnancy/lactation: Discuss adverse effects of triptans during pregnancy and breastfeeding with patients of childbearing potential 4