Imitrex is a headache medicine that narrows blood vessels around the brain. Sumatriptan also reduces substances in the body that can trigger headache pain, nausea, sensitivity to light and sound, and other migraine symptoms.

Imitrex is available as oral tablets, a nasal spray, and as an injection. It used to treat migraine headaches in adults. Imitrex will only treat a headache. It will not prevent headaches or reduce the number of attacks.

Imitrex should not be used to treat a common tension headache or a headache that causes loss of movement on one side of your body. Use this medicine only if your condition has been confirmed by a doctor as migraine headaches.

You should not use Imitrex if you have uncontrolled high blood pressure, heart problems, certain heart rhythm disorders, a history of heart attack or stroke, or circulation problems that cause a lack of blood supply within the body.

Do not use this medicine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

Also tell your doctor if you are taking an antidepressant such as citalopram (Celexa), desvenlafaxine (Pristiq), duloxetine (Cymbalta), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), paroxetine (Paxil), sertraline (Zoloft), or venlafaxine (Effexor).

Imitrex will only treat a headache that has already begun. It will not prevent headaches or reduce the number of attacks.

Do not use Imitrex within 24 hours before or after using any other migraine headache medicine.

Use Imitrex as soon as you notice headache symptoms. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may receive your first dose in a hospital or clinic setting to quickly treat any serious side effects.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Take a Imitrex tablet whole with a full glass of water. Do not split the tablet.

After using Imitrex: If your headache does not completely go away, or goes away and comes back, use a second dose if it has been at least 2 hours since your first dose.

Never use more than your recommended dose. Overuse of migraine headache medicine can make headaches worse. Tell your doctor if the medicine seems to stop working as well in treating your migraine attacks.

Do not take more than 200 milligrams of oral Imitrex within 24 hours.

Do not use more than 40 milligrams of Imitrex nasal spray within 24 hours.

Call your doctor if your symptoms do not improve, or if you have more than 4 headaches in one month (30 days).

Store at room temperature away from moisture, heat, and light. Do not store in a refrigerator. Do not freeze.

Usual Adult Dose for Migraine:

Use only after a clear diagnosis of migraine has been established

Oral:
Initial dose: 25 mg, 50 mg, or 100 mg orally, once
-If some response to first dose occurs, a second dose may be administered at least 2 hours after first dose if needed
-Oral doses of 50 and 100 mg may provide greater relief than 25 mg; however, a 100 mg dose may not provide greater effect than a 50 mg dose
Maximum dose: 200 mg per 24 hours

Intranasal:
Nasal spray: Initial dose: 5 mg, 10 mg, or 20 mg into one nostril, once
-Administer the 5 and 20 mg doses as a single spray in 1 nostril; the 10 mg dose may be administered as 5 mg into each nostril
-If some response to first dose occurs, a second dose may be administered at least 2 hours after first dose if needed
Maximum dose: 40 mg per 24 hours

Comments:
-Treatment should be started at the first sign of a migraine headache, or associated symptoms such as nausea, vomiting, or photophobia; this drug should not be used for migraine prophylaxis.
-Higher doses may have a greater effect, but also carry a greater risk of adverse reactions.
-The safety of treating an average of more than 4 headaches in a 30 day period has not been established.

Use: For the acute treatment of migraine with or without aura.

You should not use Imitrex if you are allergic to sumatriptan, or if you have ever had:

• heart problems, or a stroke (including "mini-stroke");

• coronary artery disease, angina (chest pain), blood circulation problems, lack of blood supply to the heart;

• circulation problems affecting your legs, arms, stomach, intestines, or kidneys;

• a heart disorder called Wolff-Parkinson-White syndrome;

• uncontrolled high blood pressure;

• severe liver disease; or

• a headache that seems different from your usual migraine headaches.

Do not use Imitrex if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

Be sure your doctor knows if you also take stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, serious infections, or prevention of nausea and vomiting. These medicines may interact with sumatriptan and cause a serious condition called serotonin syndrome.

To make sure Imitrex is safe for you, tell your doctor if you have ever had:

• liver or kidney disease;

• epilepsy or other seizure disorder;

• high blood pressure, a heart rhythm disorder; or

• risk factors for coronary artery disease (such as diabetes, menopause, smoking, being overweight, having high blood pressure or high cholesterol, having a family history of coronary artery disease, or being older than 40 and a man).

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Sumatriptan can pass into breast milk. Do not breast-feed within 12 hours after using Imitrex. If you use a breast pump during this time, throw out any milk you collect. Do not feed it to your baby.

Imitrex is not approved for use by anyone younger than 18 years old.

Since Imitrex is used when needed, it does not have a daily dosing schedule. Call your doctor if your symptoms do not improve after using this medicine.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include tremors, skin redness in your arms or legs, weakness, loss of coordination, breathing problems, blue-colored lips or fingernails, vision problems, or a seizure (convulsions).

Do not use Imitrex within 24 hours before or after using another migraine headache medicine, including:

• sumatriptan injection, almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, zolmitriptan; or

• ergot medicine such as dihydroergotamine, ergotamine, ergonovine, or methylergonovine.

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

Get emergency medical help if you have signs of an allergic reaction to Imitrex: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using Imitrex and call your doctor at once if you have:

• sudden and severe stomach pain and bloody diarrhea;

• severe chest pain, shortness of breath, irregular heartbeats;

• a seizure (convulsions);

• severe headache, blurred vision, pounding in your neck or ears;

• blood circulation problems in your legs or feet - cramps, tight or heavy feeling, numbness or tingling, muscle weakness, burning pain, cold feeling, color changes (pale or blue), hip pain;

• heart attack symptoms - chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;

• high levels of serotonin in the body - agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, vomiting, diarrhea; or

• signs of a stroke - sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance.

Common Imitrex side effects may include:

• pain or tight feeling in your chest, throat, or jaw;

• pressure or heavy feeling in any part of your body;

• numbness or tingling, feeling hot or cold;

• dizziness, drowsiness, weakness;

• unusual or unpleasant taste in your mouth after using the nasal medicine;

• pain, burning, numbness, or tingling in your nose or throat after using the nasal medicine; or

• runny or stuffy nose after using the nasal medicine.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Using Imitrex while you are using certain other medicines can cause high levels of serotonin to build up in your body, a condition called "serotonin syndrome," which can be fatal. Tell your doctor if you also use:

• medicine to treat depression or a psychiatric disorder;

• medicine for Parkinson's disease;

• medicine for serious infections;

• herbal products;

• stimulant medicine;

• opioid medicine; or

• medicine to prevent nausea and vomiting.

This list is not complete. Other drugs may interact with sumatriptan, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.