Eletriptan (Relpax) is an oral second-generation triptan. It causes intracranial vasoconstriction and is used in the acute treatment of patients with migraine headache.

Eletriptan Uses:

• Migraines:

  • It is prescribed for the acute treatment of migraines, aura or not.

Adult dose:

 Note:

• In case of ineffective first dose, Re-evaluation of diagnosis is suggested.
• Safety of treating >3 headaches/month has not been established.

Eletriptan (Relpax) Dose in the treatment of Acute migraine:

• Oral: Initial:
  • 20 - 40 mg as a single dose
  • 40 mg is the maximum dose per dose.
  • If there is a transient improvement in headache and headache returns, 2 hours after the first dose, the dose can be repeated.
  • The maximum dose in a day: 80 mg per day

Note: In clinical trials, 80 mg single dose has been studied and found to be associated with a slightly greater incidence of adverse reactions.

Use in Children:

Not indicated. 

Pregnancy Risk Factor C

• Studies on animal reproduction show that eletriptan can cause adverse effects in pregnancy.
• The safety of eletriptan during pregnancy in humans is not known at this time. You should consider other safer agents.

Use of Eletriptan while breastfeeding

• It excretes from breast milk.
• Study of 8 lactating mothers where 80 mg was administered in a single dose
• Breast milk contained 0.02% of maternal dose. There was also a variable milk-plasma ratio. The active metabolite could not be measured
• It is best to avoid using it in the breastfeeding mothers.

Dose in Kidney disease: 

No dose adjustments listed in the manufacturer's labeling However, on the basis of  pharmacokinetic analysis, adjustments may not be required 

Eletriptan (Relpax) Dose in Liver disease:

• Mild to moderate impairment:
  • Dose adjustment not required.
• Severe impairment:
  • Not recommended.

Side Effects of Eletriptan (Relpax):

• Cardiovascular:

  • Chest Pain
    • Chest Tightness
    • Pain, And Pressure
  • Palpitations

• Central Nervous System:

  • Dizziness
  • Drowsiness
  • Headache
  • Paresthesia
  • Chills
  • Hypertonia
  • Hypoesthesia
  • Pain
  • Vertigo

• Dermatologic:

  • Diaphoresis

• Gastrointestinal:

  • Nausea
  • Xerostomia
  • Abdominal Pain
  • Dyspepsia
  • Dysphagia

• Neuromuscular & Skeletal:

  • Weakness
  • Back Pain

• Respiratory:

  • Pharyngitis

Contraindications to Eletriptan (Relpax):

• Ischemic heart disease, e.g. Angina pectoris, history and documentation of MI, silent ischemia
• Prinzmetal angina and coronary artery vasospasm.
• Wolff Parkinson-White syndrome and arrhythmias in association with cardiac accessory conduction pathway disorders
• History of strokes or TIA
• Evidence or history of hemiplegic and basilar migraine
• Peripheral Vascular Disease
• Ischemic bowel disease
• Hypertension uncontrolled
• Recent (within 24hrs) use of another 5-HT agonist or an ergotamine containing medication (eg dihydroergotamine, methysergide).
• Recent use of any of the following potent CYP3A4 inhibitors (within 72 hours): ketoconazole. Itraconazole. Nefazodone. Troleandomycin. Clarithromycin. Ritonavir.
• Hypersensitivity to any component eletriptan has been reported

Additional contraindications are included in Canadian labeling

• Cardiac arrhythmias (especially Tachycardias)
• Heart disease of the valvular kind
• congenital heart disease
• Atherosclerotic Disease
• Ophthalmoplegic migraine
• Raynaud syndrome
• Severe hepatic impairment.

Because these agents share similar chemical structures and functions, there is no evidence of allergenic cross-reactivity. These reactions cannot be ruled out.

Warnings and precautions

• Anaphylactic/Anaphylactoid reactions

  • Anaphylaxis, anaphylactoid and hypersensitivity reactions (including angioedema), have been reported as life-threatening reactions.
  • Contraindicated in cases of hypersensitivity to any component of eletriptan.

• Cardiac events

  • Use of 5-HT agonists has been associated with cardiac arrest, transient ischemia and myocardial injury, as well as coronary artery vasospasm and cardiac arrest. Some events can occur in a matter of hours.
  • If these symptoms occur, discontinue treatment
  • Patients with chest pain, pressure, tightness or other symptoms that suggest angina after using it should consult a doctor immediately.
  • Prinzmetal or coronary artery disease should be evaluated. If dosing is resumed and symptoms continue, ECG monitoring should be performed.

• Cerebrovascular events

  • Serotonin agonists have been linked to strokes and subarachnoid hemorhage (some even fatal).
  • Contraindicated in combination with TIA or a history of stroke.

• High blood pressure

  • Those with no history of hypertension have also reported significant elevations in blood pressure.
  • Uncontrolled hypertension is a reason to avoid this medication.
  • It is a good idea to monitor blood pressure

• Serotonin syndrome

  • Serotonin syndrome can be caused by 5-HT agonists when they are combined with other serotonergic drug or drugs that reduce eletriptan metabolism.
  • Serotonin syndrome symptoms include nausea, vomiting, diarrhea, hyperthermia and incoordination.
  • Combining serotonin precursors, e.g. It is not advised to use tryptophan.
  • When combined use of SSRIs is recommended, closely monitor, especially during the initiation phase and as dose increases occur.
  • If you suspect serotonin syndrome, discontinue eletriptan.

• Vasospasm-related events

  • With serotonin agonists, peripheral vascular ischemia, GI vascular ischemia and infarction have been reported.

• Coronary artery disease

  • Perform a cardiovascular assessment first. Avoid the medication if the patient has a high risk of developing CAD (such as hypertension, high cholesterol, smoking, obesity, diabetes, or a significant family history of CAD).
  • The initial dose should be given at your doctor's office if a positive cardiovascular exam has been performed.
  • ECG monitoring might be necessary.
  • These patients should have their cardiovascular health monitored on a regular basis during long-term intermittent use.

• Hepatic impairment

  • Patients with severe hepatic impairment should not use this product.

Eletriptan: Drug Interaction

Note: Drug Interaction Categories:

• Risk Factor C: Monitor When Using Combination
• Risk Factor D: Consider Treatment Modification
• Risk Factor X: Avoid Concomitant Use

Monitoring parameters:

• Severity of Headache
• Signs and symptoms indicating angina
• Blood pressure
• Heart rate
• ECG with the first dose is given to individuals who have high cholesterol, are obese, have diabetes, smoke, or have a significant family history of the condition.
• Signs and symptoms of serotonin syndrome and hypersensitivity reactions

How to administer Eletriptan (Relpax)?

It is administered orally on the onset of symptoms. It can be taken with or without food. 

Mechanism of action of Eletriptan (Relpax):

• There are many serotonin receptors. It acts as a selective agonist of 5HT1 intracranial blood vessels. It reduces neurogenic inflammation and vasoconstriction associated with antidromic neural transmission.

Absorption:

• Well absorbed

Protein binding:

• About 85%

Metabolism:

• It is metabolized in the liver via CYP3A4; forms one  active metabolite

Bioavailability:

• About 50%,
• Bioavailability is increased with high-fat meal

Half-life elimination:

• ~4 hours (Elderly: 4.4 to 5.7 hours)
• Metabolite: ~13 hours

Time to peak, plasma:

• 1.5 to 2 hours

International Brand Names of Eletriptan:

• Relpax
• APO-Eletriptan
• AURO-Eletriptan
• GD-Eletriptan
• PMS-Eletriptan
• TEVA-Eletriptan
• Demigra
• Elle
• Migrablock
• Relert
• Relpax
• Tromzalor

Eletriptan Brand Names in Pakistan: