Imitrex vs Relpax

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For patients who suffer from migraines, certain medications can help to alleviate the severe pain and other symptoms associated with these debilitating headaches. Imitrex and Relpax are two such drugs that are often prescribed for migraine relief. They each impact different mechanisms in the brain but both have been effective in treating acute migraines. Imitrex (Sumatriptan) works by stimulating serotonin (5-HT) receptors in the brain which causes vasoconstriction of blood vessels aiding to relieve a migraine. Relpax (Eletriptan), on the other hand, is also a triptan medication like Sumatriptan, yet it has been shown to remain longer in your system potentially providing extended relief compared to Imitrex.

What is Imitrex?

Sumatriptan (the generic name for Imitrex) was one of the first drugs in a class known as triptans, which were designed specifically to manage migraine attacks. Sumatriptan was approved by the FDA in 1992. It works by constricting blood vessels and decreasing inflammation within the brain, thereby relieving pain. It is prescribed mainly for acute treatment of migraines with or without aura.

Eletriptan (marketed under the brand name Relpax) is also a member of this drug class and received FDA approval almost a decade later. Similar to sumatriptan, eletriptan alleviates migraine symptoms by narrowing blood vessels around the brain and reducing substances that can trigger headache pain, nausea, sensitivity to light and sound.

Both these medications have similar side effects including pressure or tightness in any part of your body, feeling strange or weak on one side of your body; however they differ slightly in their potency and speed at which they work. Eletriptan tends to be more potent than sumatriptan but may take longer time for onset action.

What conditions is Imitrex approved to treat?

Imitrex and Relpax are both approved for the treatment of acute migraine attacks:

  • Imitrex (sumatriptan) is used to treat severe migraines as well as cluster headaches in adults. It's not intended to prevent migraines or reduce the number of attacks but can help alleviate symptoms once they start.
  • Relpax (eletriptan) is also designed to treat acute migraine attacks with or without aura in adults, but it doesn't prevent future migraines nor lessen their occurrence.

How does Imitrex help with these illnesses?

Imitrex and Relpax are medicines commonly used to treat migraines. They operate by stimulating serotonin (5-HT1B/1D) receptors in the brain, which causes the blood vessels in the brain to constrict. This constriction helps to relieve migraine symptoms.

Imitrex, otherwise known as Sumatriptan, interacts with these receptors on nerve endings within cranial blood vessels and inhibits pro-inflammatory neuropeptide release, thereby reducing inflammation and relieving pain. It is thought that during a migraine attack there's an increase of blood flow due to vessel dilation; Imitrex works against this process.

Relpax or Eletriptan also stimulates 5-HT1B/1D receptors causing vasoconstriction but it has a higher binding affinity - meaning it binds more strongly - compared to Imitrex. The stronger binding could potentially translate into better efficacy for some patients although individual responses do vary.

What is Relpax?

Relpax, also known as eletriptan, is a triptan drug that acts as a selective serotonin receptor agonist. It works by stimulating serotonin (a neurotransmitter) receptors in the brain which causes the muscles surrounding the blood vessels in the brain to contract and narrow the blood vessels. This helps to relieve migraine headaches. Relpax was first approved by the FDA in 2002.

Unlike Imitrex, another triptan used for similar purposes, Relpax does not just act on any serotonin receptor but specifically targets those located on cranial arteries and veins. Due to this specificity of action, it can reduce side effects associated with non-specific binding.

Common side effects include dizziness, nausea and weakness but these are usually mild and transient. However, like other triptans such as Imitrex or sumatriptan, serious cardiac events including heart attack have been reported rarely in patients using Relpax for migraine attacks.

What conditions is Relpax approved to treat?

Relpax, also known by its generic name eletriptan, is approved for the treatment of:

  • Acute migraines in adults (with or without aura)

It's a triptan medication that works by narrowing blood vessels around the brain and affects certain nerves in the brain to reduce headache, nausea, sensitivity to light/sound, and other migraine symptoms.

How does Relpax help with these illnesses?

Serotonin is a neurotransmitter that has various functions in the body, including roles in mood regulation, appetite control, and sleep. Some studies have found an association between abnormal serotonin levels and migraines. Relpax works by stimulating serotonin receptors in the brain to narrow blood vessels around the brain. This action reduces swelling of blood vessels associated with migraine headaches. While Imitrex also acts on serotonin receptors, it may not be as effective for some patients due to individual variations in receptor subtype sensitivity or other factors. Since Relpax does not significantly affect norepinephrine or dopamine levels, it can be an ideal choice for those who don't respond well to triptan drugs like Imitrex or prefer fewer side effects.

How effective are both Imitrex and Relpax?

Both sumatriptan (Imitrex) and eletriptan (Relpax) have established histories of success in treating patients with migraines, each being approved by the FDA in 1991 and 2002 respectively. As they belong to the same class of drugs known as triptans, their mechanisms of action are similar - both selectively target serotonin (5-HT) receptors located on blood vessels within the brain in order to reduce inflammation and constrict these vessels, thus relieving migraine symptoms.

A double-blind clinical trial conducted in 2004 directly compared sumatriptan and eletriptan's effectiveness at alleviating acute migraines. Both medications demonstrated comparable efficacy at managing symptoms such as headache pain intensity, nausea, photophobia, phonophobia etc., with a slight edge towards Relpax for sustained pain relief over a period of up to 24 hours.

In terms of safety profiles, both medications are generally well-tolerated with mild side effects that usually dissipate after usage is stopped. However, since these medications can cause tightening or contractions in coronary arteries thereby increasing heart rate or blood pressure levels slightly; they should be used cautiously among patients who already have pre-existing cardiovascular disease risks.

Furthermore, despite belonging to the same drug class category - Triptans; Eletriptan has been reported by some studies as having somewhat greater efficacy than Sumatriptan particularly when it comes to maintaining freedom from migraine-related symptoms upto 24 hours post administration. This could make it an ideal option for individuals who suffer from long-lasting migraines or those whose attacks tend to recur within short time periods.

That said ,both Sumatriptan & Eletriptan are considered first-line treatments for moderate-to-severe migraine attacks due to their robust effectiveness data across multiple trials spanning years .Therefore which medication would work best largely depends upon individual patient characteristics including but not limited medical history,tolerance profile,duration/severity/frequency/patterns associated with migrainous episodes among others factors.

abstract image of a researcher studying a bottle of drug.

At what dose is Imitrex typically prescribed?

Oral dosages of Imitrex range from 25-100 mg per dose, but studies have suggested that 50 mg is sufficient for treating most acute migraine attacks in adults. For Relpax, the recommended start dosage is 40 mg. If the headache returns or if full effect was not achieved, a second dose may be taken after two hours, but should not exceed total daily dosage of 80 mg. Neither medication is recommended for children and adolescents without doctor's advice. In any case, maximum daily intake for Imitrex should not exceed 200mg while for Relpax it shouldn't go beyond 80mg.

At what dose is Relpax typically prescribed?

Relpax treatment for migraines usually begins with a dosage of 20-40 mg, taken by mouth at the onset of symptoms. If the migraine persists, another dose may be taken two hours after the first, but no more than 80 mg should be consumed within any 24-hour period. This approach ensures that each dose has sufficient time to work before another is introduced to your system. It's important that if you don't experience relief or if your symptoms worsen after taking Relpax at these prescribed dosages, consult with your healthcare provider promptly to discuss potential alternatives or adjustments in therapy.

What are the most common side effects for Imitrex?

Common side effects associated with Imitrex include:

  • Sensations of warmth or cold
  • Pressure or tightness in any part of the body, including the chest and throat
  • Weakness
  • Unusual feelings or sensations (paresthesia)
  • Dizziness, drowsiness
  • Nausea and vomiting
  • Tiredness

For Relpax, users may experience:

  • Nausea
  • Dry mouth
  • Dizziness
    -Tingling/numb sensation
    -Warmth/cold sensation
    -Muscle weakness

Always consult your doctor if you notice any severe side effects.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Imitrex?

While both Imitrex and Relpax are generally considered safe, they can cause side effects in rare cases. For Imitrex, these may include:

  • Chest pain or tightness; a feeling of heaviness in the chest
  • Shortness of breath
  • Irregular heartbeat
  • Signs of stroke such as confusion, difficulty speaking, sudden severe headache, sudden loss of coordination or balance
  • Allergic reactions: hives; difficulty breathing; swelling of your face, lips, tongue or throat

For Relpax on the other hand:

  • Heart-related issues: Chest pain spreading to the arm or shoulder; nausea, sweating.
  • High levels of serotonin in the body - agitation hallucinations fever fast heart rate overactive reflexes vomiting diarrhea loss-of-coordination fainting -Severe nervous system reaction - very stiff (rigid) muscles high fever sweating fast uneven heartbeats tremors feeling like you might pass out.

If you experience any serious side effects from either medication it is important to seek immediate medical attention.

What are the most common side effects for Relpax?

Relpax (eletriptan), like Imitrex, is a triptan medication used to treat migraines. It does have its own side effects that you should be aware of:

  • Nausea or vomiting
  • Dry mouth or unusual taste in the mouth
  • Sensations of warmth, heaviness, pressure or tightness (not pain) in different parts of the body
  • Dizziness or sleepiness
  • Muscle weakness
  • Flushing (reddening and warming) of skin It's important to note that these are not all possible side effects and Relpax may affect individuals differently. Always consult with your healthcare provider for advice tailored to your health situation.

Are there any potential serious side effects for Relpax?

Relpax, while generally well-tolerated, can cause certain severe side effects in some instances. These include:

  • Indications of an allergic reaction such as swelling in your face or throat, hives and difficulty breathing
  • Unusual heart rhythm or rapid heartbeat
  • Symptoms suggesting a stroke including sudden numbness on one side of the body (especially in the face, arm, or leg), confusion and trouble speaking
  • Severe stomach pain and bloody diarrhea
  • Signs indicating high levels of serotonin in the body such as hallucination, fever, fast heart rate, overactive reflexes
  • High blood pressure symptoms like severe headache, blurred vision buzzing in your ears

These are serious conditions that require immediate medical attention. If you experience any of these symptoms after taking Relpax consult with your healthcare provider immediately.

Contraindications for Imitrex and Relpax?

Both Imitrex and Relpax, like most other migraine medications, may exacerbate certain symptoms in some people. If you notice your headache becoming more severe or frequent, experience sudden/rapid heartbeat, chest pain or pressure, unusual sweating or changes in body temperature after taking these medications, please seek immediate medical attention.

Neither Imitrex nor Relpax should be taken if you are currently using or have recently used drugs known as 5-hydroxytryptamine receptor agonists (triptans) or ergotamines. Always inform your healthcare provider about all the medications you take; triptans and ergotamines will require a clearance period of about 24 hours from the system to prevent dangerous interactions with either Imitrex or Relpax.

How much do Imitrex and Relpax cost?

For the brand name versions of these drugs:

  • The price of 9 tablets of Imitrex (100 mg) averages around $160, which works out to approximately $18 per dose.
  • The price for 6 tablets of Relpax (40 mg) is about $120, which equals to roughly $20 per dose.

Thus, if you need a higher dosage or more frequent use, then brand-name Imitrex could be less expensive on a per-dose basis. However, cost should not be your primary consideration in determining which of these migraine medications is right for you.

As it stands with generic versions sumatriptan (generic Imitrex) and eletriptan (generic Relpax), costs are significantly lower:

  • Sumatriptan is available in packs ranging from 5 to 15 tablets with the average cost being between $1.50 - $6.00 per tablet.
  • Eletriptan tends to be pricier than its counterpart but still considerably cheaper than its branded version; costs vary widely depending on insurance coverage and pharmacy choice but typically range from about $2 - $15 per tablet.

Remember that while both work effectively against migraines, their effectiveness can differ depending on individual patient response so always consult your healthcare provider before making any changes.

Popularity of Imitrex and Relpax

Sumatriptan, under the brand name Imitrex, was estimated to have been prescribed to about 2.1 million people in the US in 2020. Sumatriptan accounted for just over 39% of triptan prescriptions (a class of drugs used specifically for treating migraines) in the US. However, it appears to be a generally preferred choice among triptans due its effectiveness and affordability.

Eletriptan, with brand versions such as Relpax, was prescribed to approximately 0.5 million people in the USA in 2020. In the US, eletriptan accounts for just under 10% of triptan prescriptions. The prevalence of eletriptan has remained relatively steady over recent years despite being more expensive than other options like sumatriptan because some patients find it more effective or better tolerated.


Both Imitrex (sumatriptan) and Relpax (eletriptan) have established records of usage in patients with migraines, supported by numerous clinical trials indicating that they are more effective than placebo treatments. In some cases, the drugs may be used together but this is subject to careful consideration by a physician as they can interact negatively. Due to their different mechanisms of action; with Imitrex acting primarily on serotonin receptors 5-HT1D and 5-HT1B, and Relpax having a higher affinity for these receptors, they tend to be prescribed under different circumstances.

Imitrex is often considered the first-line treatment option whereas Relpax might usually be considered for those who do not respond well to initial triptans or need longer-lasting relief from migraine symptoms.

Both medications are available in generic form which offers significant cost savings especially for individuals paying out-of-pocket. Both Imitrex and Relpax may require an adjustment period meaning that optimal effects may not be noticeable right away.

The side effect profile is similar between both drugs with them being generally well-tolerated although each has its unique set of potential side effects like chest tightness or pressure with Imitrex and dizziness or nausea with Relpax. For both drugs, patients should closely monitor their symptoms after administration especially when starting treatment and seek medical help immediately if adverse reactions occur.