Imitrex vs. Relpax

Reviewed on 10/3/2023

Are Imitrex and Relpax the Same Thing?

Imitrex (sumatriptan) and Relpax (topiramate) are used to treat migraine headaches.

Relpax is also used for preventing epileptic seizures and migraine headaches.

Imitrex is a selective serotonin receptor agonist (also called a triptan) and Relpax is an anticonvulsant.

What Are Possible Side Effects of Imitrex?

Common side effects of Imitrex include:

  • mild headache (not a migraine),
  • pain or chest tightness,
  • pressure or heavy feeling in any part of your body,
  • weakness,
  • feeling hot or cold,
  • dizziness,
  • spinning sensation,
  • drowsiness,
  • nausea,
  • vomiting,
  • drooling,
  • unusual taste in your mouth after using nasal spray,
  • burning/numbness/pain/irritation in your nose or throat after using nasal spray, or
  • flushing (warmth, redness, or tingling under the skin).

What Are Possible Side Effects of Relpax?

Common side effects of Relpax include:

  • mild headache (not a migraine),
  • tingling/numbness,
  • nausea,
  • upset stomach,
  • stomach pain or cramps,
  • weakness,
  • drowsiness,
  • dizziness,
  • pressure or heavy feeling in any part of your body,
  • dry mouth, or
  • flushing (warmth, redness, or tingling under your skin).

Tell your doctor if you have serious side effects of Relpax including:

  • blue fingers/toes/nails, or
  • cold hands or feet.

What is Imitrex?

Imitrex (sumatriptan) is a selective serotonin receptor agonist used in oral, intranasal or injectable dosage form to treat migraine headaches. Imitrex is available as a generic drug.

What is Relpax?

Relpax (eletriptan hydrobromide) is a selective serotonin receptor agonist used to treat migraine headaches. Relpax will only treat a headache that has already begun. Relpax will not prevent headaches or reduce the number of attacks.

What Drugs Interact With Imitrex?

Imitrex may interact with sibutramine (Meridia); monoamine oxidase inhibitors (MAOIs) isocarboxazid (Marplan); selective serotonin reuptake inhibitors, fluoxetine (Prozac) and sertraline (Zoloft), serotonin; norepinephrine reuptake inhibitors, venlafaxine (Effexor)) and duloxetine (Cymbalta); and ergot-containing medications, dihydroergotamine (Migranal) and ergotamine (Methergine).

What Drugs Interact With Relpax?

Relpax should not be used with sibutramine because a very serious interaction may occur. Relpax should not be used within 72 hours of use of drugs affecting liver enzymes that remove eletriptan from your body such as nefazodone, azole antifungals, antibiotics, and protease inhibitors. Relpax should not be used within 24 hours of use of ergot-type drugs or other migraine drugs because of serious interactions. Antidepressants, St. John's wort, antihistamines, anti-seizure drugs, medicine for sleep or anxiety, muscle relaxants, narcotic pain relievers, and psychiatric medicines may all adversely interact with this drug. Discuss all medications you are taking with your doctor.

How Should Imitrex Be Taken?

The maximum single recommended adult dose of Imitrex Injection for the acute treatment of migraine or cluster headache is 6 mg injected subcutaneously. For the treatment of migraine, if side effects are dose limiting, lower doses (1 mg to 5 mg) of Imitrex may be used.

How Should Relpax Be Taken?

A single dose of 20 mg or 40 mg is effective for the acute treatment of migraine in adults. After taking Relpax, you must wait 2 hours before taking another dose.


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GSK. Imitrex Product Information.
Pfizer. Relpax Product Information.

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