Relpax (eletriptan) is a brand-name prescription medication. It’s approved by the Food and Drug Administration (FDA) to treat migraine that occurs with or without aura in adults.

Relpax is typically a long-term treatment. However, it isn’t taken on a regular basis. Instead, you’ll only take it as needed for migraine.

Here are some fast facts about Relpax:

  • Active ingredient: eletriptan
  • Drug class: triptans (also called serotonin receptor agonists)
  • Drug form: oral tablet

Relpax is only prescribed for adults who’ve been diagnosed with migraine. It doesn’t prevent migraine attacks or treat cluster headaches.

As with other drugs, Relpax can cause side effects. This article talks about the common, mild, and serious side effects of Relpax. For a general overview of Relpax, see this article.

Relpax can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took Relpax in clinical trials:

  • asthenia (feeling weak)
  • dizziness
  • nausea*
  • drowsiness*

* For more information about this side effect, see “Side effect specifics” below.

Mild side effects can occur with Relpax. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to Relpax’s prescribing information.

Mild side effects that have been reported with Relpax include:

  • asthenia (feeling weak)
  • dizziness
  • tingling or prickling sensations
  • pressure or pain in your stomach or abdomen
  • dry mouth
  • indigestion
  • sensations of pain, pressure, or tightness*
  • nausea*
  • drowsiness*

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking Relpax and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Side effect specifics” below.

Relpax may cause serious side effects in some people. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Relpax’s prescribing information.

If you develop serious side effects while taking Relpax, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

  • Medication overuse headache from taking Relpax too often. Symptoms can include:
    • migraine headaches that are more severe or occur more often than usual
  • Serotonin syndrome, which is a group of symptoms that can occur when serotonin levels become too high. Symptoms can include:
    • dilated pupils
    • increased sweating
    • fast heart rate
    • nausea
    • vomiting
  • Stroke or other disorders that affect the blood supply to the brain. Symptoms can include:
    • weakness in your face, arm, or leg, typically on one side of the body
    • trouble speaking
  • High blood pressure, which may cause symptoms if it becomes very high:
    • severe headache
    • vision changes
  • Vasospasms (sudden narrowing of an artery, which reduces blood flow to certain areas of the body). Symptoms of this side effect may vary depending on where these spasms occur, and can include:
    • pain, numbness, or color changes in your fingers or toes
    • cramping, pain, or tingling in your legs or feet
  • Heart-related side effects.*
  • Allergic reaction.*†

* For more information about this side effect, see “Side effect specifics” below.
† An allergic reaction is possible after taking Relpax. However, this side effect wasn’t reported in clinical trials.

Relpax may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Is weight gain a side effect of Relpax?

No. Weight gain isn’t a side effect of Relpax. Weight gain wasn’t reported in clinical trials of the drug.

Talk with your doctor if you’ve had weight gain since starting Relpax. Weight gain may raise your risk of having heart problems while taking Relpax. Your doctor can advise you on whether it’s safe for you to continue Relpax treatment. They may also suggest ways to manage your weight.

How do side effects of the 20-mg and 40-mg strengths of Relpax compare?

Certain side effects of Relpax are more likely to occur with a higher dose compared with a lower dose.

Below are some examples of side effects that occurred more frequently in people who took a 40-milligram (mg) dose compared with a 20-mg dose in Relpax’s clinical trials:

  • asthenia (feeling weak)
  • dizziness
  • nausea
  • drowsiness
  • pressure or pain in your stomach or abdomen
  • sensations of pain, pressure, or tightness

These side effects don’t occur in everyone who takes Relpax. Talk with your doctor if you have bothersome side effects or questions about your dosage.

Are there any long-term side effects of Relpax? How long do Relpax side effects last?

Relpax isn’t likely to cause long-term side effects. The drug’s more common side effects, such as dizziness and drowsiness, typically go away within a few hours or by the next day.

Doctors have been prescribing Relpax since 2002, when it was approved by the Food and Drug Administration (FDA). Since then, there have been rare reports of serious side effects in people who took triptans (the drug class that Relpax belongs to). These side effects have mainly been related to the heart and blood vessels, such as heart attack or stroke, which may affect your health long term.

People who have certain risk factors for heart or blood vessel disease have a higher chance of developing these long-term side effects. Because of this, your doctor will consider your overall health and medical history before prescribing Relpax. They’ll talk with you about any risk factors you may have and whether it’s safe for you to take Relpax.

Learn more about some of the side effects that Relpax may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for Relpax.

Heart-related side effects

It’s possible to develop heart side effects while taking Relpax. Heart-related side effects have also been reported in people taking other triptans. (Relpax belongs to a drug class called triptans).

Some examples of heart-related side effects that have been reported with triptans include heart attack and arrhythmia (changes in heart rhythm). Symptoms can include:

People who have certain heart or blood vessel conditions, such as coronary artery disease, shouldn’t take Relpax. (For more details, see the “Precautions for Relpax” section below.)

Also, people who have certain risk factors have a higher chance of developing heart problems while taking Relpax (and in general). Some examples of these risk factors include:

Due to this possibility, your doctor will likely not prescribe Relpax if you have multiple risk factors.

What you can do

Before starting Relpax, talk with your doctor about your overall health, your medical history, and any risk factors you may have. They’ll guide you on whether it’s safe for you to take Relpax. They can also advise you on ways to lower your risk of heart-related side effects.

If you have certain risk factors, your doctor may have you take your first dose of Relpax in their office so they can monitor your heart. If your doctor decides that Relpax is safe for you, they may check your heart occasionally during Relpax treatment.

If you develop symptoms of a potential heart problem, tell your doctor right away.

Drowsiness

Feeling drowsy can be a side effect of Relpax. Drowsiness was commonly seen in people who took the drug in clinical trials.

What you can do

You may feel drowsy for several hours after taking a dose of Relpax. Only take a dose when you’re at home or somewhere that you’ll be able to rest. Avoid doing activities that require you to be alert, such as driving or operating heavy machinery.

If drowsiness from Relpax becomes excessive, talk with your doctor. They may change your dose or recommend a different migraine treatment option.

Nausea

Nausea can occur while taking Relpax. This side effect was common in clinical trials of the drug.

Keep in mind that nausea is also a common symptom of migraine headaches.

What you can do

If you commonly get nausea as a migraine symptom, it should ease as your migraine goes away, typically within 2 hours of taking Relpax.

However, if nausea doesn’t go away, is worse than usual, or leads to excessive vomiting, talk with your doctor. In some cases, your doctor may prescribe antinausea medications to ease migraine-related nausea.

Sensations of pain, pressure, or tightness

You may have discomfort in your jaw, throat, neck, or chest after taking a dose of Relpax. Some people had this side effect in the drug’s clinical trials, though it was less common.

Symptoms may include the following sensations in the jaw, throat, neck, or chest:

  • pain
  • tightness
  • pressure
  • heaviness

Some people may also have difficulty swallowing due to tightness in their throat.

What you can do

These sensations are typically mild and should go away on their own within a few minutes to hours.

However, if these symptoms become severe or don’t go away, you should seek medical attention. This is because similar symptoms may also be a sign of a heart attack or other heart problems. And Relpax can cause serious heart problems, especially in people with certain conditions or risk factors. (To learn more, see “Heart-related side effects” above.)

If you have questions about this side effect, talk with your doctor or pharmacist.

Allergic reaction

As with most drugs, Relpax can cause an allergic reaction in some people. However, this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking Relpax. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take Relpax. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health, such as:

Conditions or factors that affect your heart or blood circulation. Due to the risk of harm, your doctor typically will not prescribe Relpax if you have certain medical conditions that affect your heart, heart rhythm, or blood circulation. Taking Relpax could worsen these conditions and lead to heart attack or stroke. Be sure to tell your doctor if you think you have any of the following conditions or factors:

* See this article for more information about drug interactions with Relpax.

Additional conditions and factors for you and your doctor to consider before starting Relpax include:

Risk factors for heart disease. Relpax can increase your risk of a heart attack. If you already have factors that raise your risk of heart disease, Relpax can further increase your risk of a heart attack. These factors can include a family history of heart disease, diabetes, high blood pressure, high cholesterol, tobacco use, and obesity. If you have any of these risk factors, your doctor may have you take your first dose of Relpax in their office while they monitor your heart. Or your doctor may recommend different migraine medication.

Allergic reaction. If you’ve had an allergic reaction to Relpax or any of its ingredients, your doctor will likely not prescribe Relpax. Ask your doctor what other medications may be better options for you.

Alcohol with Relpax

Alcohol isn’t known to interact with Relpax.

However, alcohol can trigger or worsen a migraine attack in some people.

Talk with your doctor about how much alcohol, if any, is safe for you to drink while taking Relpax.

Pregnancy and breastfeeding while taking Relpax

It’s not known if Relpax is safe to take during pregnancy or while breastfeeding. The drug’s clinical trials didn’t include people who were pregnant or breastfeeding.

However, animal studies showed an increased risk of certain problems in offspring. These included low birth weight and developmental problems in the heart, spine, and bones. However, animal studies don’t always accurately predict what will happen in humans.

Research shows that Relpax can pass into breast milk. This means that a child who is breastfed may be exposed to the medication. To minimize how much of the drug your child is exposed to, avoid breastfeeding for 24 hours after taking your dose of Relpax.

If you’re pregnant or breastfeeding, or are planning either, talk with your doctor before starting Relpax. They may recommend a different medication to treat migraine.

The side effects of Relpax are typically mild and temporary. Serious side effects are possible, especially if you have certain risk factors.

If you’d like to learn more about Relpax, talk with your doctor or pharmacist. They can help answer any questions you have about side effects of taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.