Eletriptan and Its Role in Acute Migraine Therapy

Eletriptan and Migraine Therapy

Eletriptan is a medication indicated for the acute treatment of migraine (with or without aura) in adult patients. It acts as a selective agonist of serotonin receptors 5-HT₁, binding primarily with high affinity to 5-HT_1B, 5-HT_1D, and 5-HT_1F receptors. It is characterized by rapid absorption and quick onset of action, with a bioavailability of approximately 50% (vs. 14% for sumatriptan) and a peak plasma concentration occurring 1−1.5 hours after administration. The biological half-life of eletriptan is about 4 hours, resulting in a lower incidence of relapse compared to sumatriptan. 

In comparative studies, eletriptan 40 mg showed the same efficacy as 100 mg sumatriptan, while at 80 mg, eletriptan was more effective. The drug is not intended for prophylactic migraine therapy or for the treatment of hemiplegic, ophthalmoplegic, or basilar migraine.

Dosage

Ideally, eletriptan should be taken as soon as possible after the onset of a migraine attack, though it is effective even at a later stage. The recommended starting dose is 40 mg. In cases of partial but insufficient effectiveness during a subsequent attack, an 80 mg dose can be chosen. In the event of a pain relapse, eletriptan can be taken again at least 2 hours after the initial dose. If the first dose is entirely ineffective, clinical studies have not demonstrated the benefit of administering an additional dose for the same attack. The maximum daily dose should not exceed 80 mg.

Adverse Effects and Contraindications

Eletriptan is generally well tolerated. Clinical studies have shown that the most common adverse effects (AEs) include asthenia (7.2%), nausea (7.8%), dizziness (5.7%), and somnolence (5.2% of patients). AEs are mostly mild and transient, and their severity is not dose-dependent. When treating with eletriptan, the following contraindications should be considered:

• moderate or severe hypertension, or untreated mild hypertension
• a history or symptoms of ischemic heart disease
• coronary artery vasospasms
• significant arrhythmias or heart failure
• ischemic peripheral vascular disease
• severe liver or kidney dysfunction
• a history of cerebrovascular accident or transient ischemic attack
• concurrent administration with ergotamine, ergotamine derivatives, or other 5-HT₁ receptor agonists (cumulative effect on coronary arteries)
• concurrent administration with potent CYP3A4 inhibitors (e.g., systemic azole antifungals, clarithromycin, verapamil, amiodarone, ritonavir)

Clinical Study Results

The efficacy of eletriptan in the acute treatment of migraine was evaluated in 7 double-blind, placebo-controlled studies involving 5,992 adult patients. All studies demonstrated that eletriptan (in all doses) was significantly more effective than placebo in alleviating headache pain within 2 hours of administration. Headache pain reduction occurred as early as 30 minutes post-administration. The efficacy of eletriptan was not affected by the duration of the attack, gender, menstrual cycle, or concomitant use of estrogen replacement therapy/oral contraceptives or prophylactic migraine medications.

The proportion of patients who achieved a pain-free state within 2 hours of taking 20 or 40 mg eletriptan was statistically significantly higher compared to placebo. Among patients with photophobia, phonophobia, and nausea associated with migraine, a lower incidence of these symptoms was observed following eletriptan administration compared to placebo.

Clinical studies also showed that most patients did not experience a return of headache pain within 2–24 hours of taking eletriptan. The proportion of patients without headache recurrence depended on the dose: at 20 mg, 72% of patients had no pain return, at 40 mg, 77%, and at the highest dose of 80 mg, 79% of patients were pain-free for the following 24 hours.

Conclusion

Eletriptan is an effective and well-tolerated medication intended for the acute treatment of migraine. Compared to sumatriptan, it boasts a rapid onset of action and a lower risk of migraine attack relapse. Before prescribing, its interactions with CYP3A4 inhibitors and other 5-HT₁ receptor agonists should be considered.

(vef)

Sources:
1. Product monograph Relpax. Upjohn Canada ULC, 2020. Available at: www.pfizer.ca/sites/default/files/202005/RELPAX_PM_E_237471_2020.05.06.pdf
2. Migraine treatment. Czech headache society, 2021. Available at: http://czech-headache.cz/lecba-migreny-2
3. SPC Relpax. Available at: www.sukl.cz/modules/medication/download.php?file=SPC168898.pdf&type=spc&as=relpax-spc