Eletriptan

Usage

Eletriptan is prescribed for the acute treatment of migraine headaches with or without aura in adults. It is not intended for preventative therapy or for cluster headaches. It is classified as a 5-HT_1B/1D receptor agonist, also known as a triptan. Eletriptan works by constricting blood vessels in the brain and reducing inflammation, thus relieving migraine symptoms.

Alternate Names

Eletriptan is the generic name. A common brand name is Relpax.

How It Works

Pharmacodynamics: Eletriptan selectively binds to 5-HT_1B/1D receptors, primarily located on intracranial blood vessels and sensory nerves of the trigeminal system. This action leads to vasoconstriction, reducing vascular inflammation, and inhibiting dural neurogenic inflammation associated with migraine.

Pharmacokinetics:

• Absorption: Eletriptan is rapidly absorbed after oral administration, reaching peak plasma concentration in about 1.5 hours. Absolute bioavailability is approximately 50% due to first-pass metabolism.
• Metabolism: Primarily metabolized in the liver, mainly via CYP3A4, to an active N-desmethyl metabolite.
• Elimination: Eletriptan and its metabolites are predominantly excreted in the urine, with a half-life of approximately 4 hours.

Dosage

Standard Dosage

Adults:

The recommended starting dose is 20 mg or 40 mg taken orally as a single dose at the onset of migraine symptoms. If symptoms persist or recur after initial relief, a second dose may be taken at least 2 hours after the first. The maximum daily dose is 80 mg within a 24-hour period.

Children:

Eletriptan use is not recommended for individuals under 18 years old, as safety and effectiveness have not been established.

Special Cases:

• Elderly Patients: Use with caution as effects on blood pressure may be more pronounced. Doses above 40 mg should be administered cautiously.
• Patients with Renal Impairment: Dose adjustment is generally not necessary in mild to moderate impairment. For severe impairment, consider a lower starting dose (20 mg) and a maximum daily dose of 40 mg.
• Patients with Hepatic Dysfunction: No dose adjustment is needed for mild to moderate hepatic impairment. Eletriptan is contraindicated in patients with severe hepatic impairment.
• Patients with Comorbid Conditions: Exercise caution in patients with cardiovascular risk factors (e.g., hypertension, diabetes, smoking), as eletriptan can cause vasoconstriction. Cardiac evaluation should be considered before prescribing eletriptan to these patients.

Clinical Use Cases

Eletriptan’s clinical use is limited to the acute treatment of migraine. It is not indicated for:

• Intubation
• Surgical Procedures
• Mechanical Ventilation
• Intensive Care Unit (ICU) Use
• Emergency Situations (e.g., status epilepticus, cardiac arrest)

Side Effects

Common Side Effects:

Dizziness, drowsiness, weakness, nausea, dry mouth, tingling sensations, warmth or cold sensation.

Rare but Serious Side Effects:

Allergic reactions (angioedema, anaphylaxis), myocardial ischemia, myocardial infarction, Prinzmetal’s angina, stroke, serotonin syndrome, increased blood pressure, peripheral vascular ischemia.

Long-Term Effects:

Medication overuse headache can occur with frequent use of triptans, leading to more frequent and severe headaches.

Adverse Drug Reactions (ADR):

Any symptoms of serotonin syndrome, chest pain, signs of stroke or heart attack, allergic reactions, sudden increase in blood pressure, or peripheral vascular ischemia should be considered serious ADRs needing immediate medical attention.

Contraindications

• Ischemic coronary artery disease (CAD), including angina pectoris, history of myocardial infarction, Prinzmetal’s angina.
• Wolff-Parkinson-White syndrome or other cardiac accessory conduction pathway disorders.
• History of stroke, transient ischemic attack (TIA), hemiplegic migraine, or basilar migraine.
• Peripheral vascular disease.
• Uncontrolled hypertension.
• Severe hepatic impairment.
• Use within 24 hours of another 5-HT₁ agonist or ergotamine-containing medication.
• Hypersensitivity to eletriptan.
• Use within 72 hours of potent CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, ritonavir).

Drug Interactions

Eletriptan can interact with a variety of medications, including:

• CYP3A4 Inhibitors: These can significantly increase eletriptan levels, potentially leading to toxicity. Avoid concomitant use or adjust dosage as needed.
• Other Triptans and Ergot Derivatives: Concurrent use can increase the risk of vasoconstriction and adverse events. Avoid using within 24 hours of each other.
• MAO Inhibitors: Concurrent use can increase the risk of serotonin syndrome.
• SSRIs/SNRIs: Co-administration may increase the risk of serotonin syndrome, although this is rare. Careful monitoring is recommended.
• Propranolol: May increase eletriptan levels. Monitor blood pressure.

Additionally, interactions can occur with OTC drugs, herbal supplements (e.g., St. John’s Wort), and certain foods (e.g., grapefruit juice).

Pregnancy and Breastfeeding

• Pregnancy: Eletriptan’s effects on pregnancy are not well-established. Use only if clearly needed and the potential benefits outweigh the risks.
• Breastfeeding: Eletriptan is excreted in breast milk in small amounts. While the risk to infants is considered low, consider avoiding breastfeeding for 24 hours after administration to minimize exposure.

Drug Profile Summary

• Mechanism of Action: 5-HT_1B/1D receptor agonist, causing vasoconstriction and reducing inflammation.
• Side Effects: Common: dizziness, drowsiness, nausea. Serious: allergic reactions, myocardial ischemia, stroke.
• Contraindications: CAD, Wolff-Parkinson-White syndrome, stroke history, uncontrolled hypertension, severe hepatic impairment, concurrent use of CYP3A4 inhibitors, other triptans, or ergot derivatives.
• Drug Interactions: CYP3A4 inhibitors, other triptans, ergot derivatives, MAOIs, SSRIs/SNRIs.
• Pregnancy & Breastfeeding: Use with caution; limited data available.
• Dosage: 20-40 mg, max 80 mg/24 hours.
• Monitoring Parameters: Blood pressure, heart rate, signs of serotonin syndrome, allergic reactions.

Popular Combinations

Eletriptan is often used alone. Combination with NSAIDs or simple analgesics like acetaminophen can be considered if needed, but monitor carefully for adverse events.

Precautions

Screen patients for cardiovascular risk factors and contraindications before prescribing. Educate patients about potential side effects, drug interactions, and the risk of medication overuse headache. Exercise caution in elderly patients.

FAQs (Frequently Asked Questions)

Q1: What is the recommended dosage for Eletriptan?

A: The standard dose is 20 mg or 40 mg. A maximum of 80 mg can be taken within 24 hours.

Q2: How soon can a second dose be taken?

A: A second dose can be taken at least 2 hours after the first dose, if needed.

Q3: Is Eletriptan safe for patients with heart disease?

A: No. Eletriptan is contraindicated in patients with CAD or other significant cardiovascular diseases.

Q4: Can Eletriptan be used to prevent migraines?

A: No. Eletriptan is designed for acute treatment of migraine attacks, not prevention.

Q5: What are the common side effects of Eletriptan?

A: Common side effects include dizziness, drowsiness, nausea, and weakness.

Q6: Can Eletriptan interact with other medications?

A: Yes. Eletriptan can interact with many medications, including CYP3A4 inhibitors, other triptans, ergotamine-containing drugs, MAOIs, and SSRIs/SNRIs. A full medication review is important before prescribing.

Q7: Can Eletriptan be used during pregnancy or breastfeeding?

A: Eletriptan should be used cautiously during pregnancy and breastfeeding, and only if the potential benefits outweigh the risks. Limited data are available, and safer alternatives may be preferred.

Q8: What should patients do if they experience chest pain after taking Eletriptan?

A: Chest pain after taking eletriptan can indicate a serious adverse event. Patients should seek immediate medical attention.

Q9: How often can Eletriptan be used?

A: Overuse of triptans can lead to medication overuse headache. Eletriptan should be used for no more than 3 migraine attacks within a 30-day period unless directed otherwise by a physician. Limit use to fewer than 10 days per month to avoid medication overuse headache.

Q10: What is the mechanism of action of Eletriptan?

A: Eletriptan is a 5-HT_1B/1D receptor agonist. It causes vasoconstriction of intracranial blood vessels and reduces inflammation, thus alleviating migraine symptoms.