Imitrex ( Sumatriptan ) is a headache medicine. It is believed to work by causing vasoconstriction (narrowing) of arteries and veins that supply blood to your head. Imitrex ( Sumatriptan ) tablets and injections are used to treat vascular headaches such as migraine and cluster headaches. Imitrex ( Sumatriptan ) will not prevent migraines or cluster headaches or reduce the number of attacks. It will only treat a migraine or cluster headache that is already occurring. Sponsored by GlaxoSmithKline, IMITREX is the most prescribed acute migraine prescription medication in the United States

What To Know
Do not take sumatriptan if the headache you are experiencing is not like other migraines that you have had. Do not take this medication if you have heart disease including angina (chest pain), history of a heart attack, or high blood pressure. Serious, even fatal, side effects involving the heart have been reported with sumatriptan. Never take more of this medication than is prescribed by your doctor. More medication will not further treat symptoms. If your symptoms are not being treated, contact your doctor.

What Is It
Sumatriptan is a headache medicine. It is believed to work by causing vasoconstriction (narrowing) of arteries and veins that supply blood to your head. Sumatriptan tablets and injections are used to treat vascular headaches such as migraine and cluster headaches. Sumatriptan will not prevent migraines or cluster headaches or reduce the number of attacks. It will only treat a migraine or cluster headache that is already occurring. Sumatriptan may also be used for purposes other than those listed in this medication guide.

Before Using
Do not take sumatriptan if you have taken a monoamine oxidase inhibitor (MAOI) such as isocarboxazid (Marplan), tranylcypromine (Parnate), or phenelzine (Nardil) in the last 14 days; have basilar or hemiplegic migraine headaches; have had a heart attack, have angina (chest pain), or have another type of heart disease; are experiencing a headache that is not like other migraines that you have had; or have taken an ergot-based medication within the last 24 hours --ergot-based medicines include methysergide (Sansert), ergotamine (Ergostat, Medihaler Ergotamine), dihydroergotamine mesylate (D.H.E., Migranal Nasal Spray), and ergotamine combination products (Cafergot, Ercaf, Wigraine, Cafatine, Cafatine-PB, Cafetrate). Before taking this medication, tell your doctor if you have taken another migraine medicine such as almotriptan (Axert), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt, Maxalt-MLT), or zolmitriptan (Zomig, Zomig-ZMT) in the past 24 hours; Taking sumatriptan may be dangerous if you have any of the conditions, or have taken any of the medications, listed above. Before taking sumatriptan, tell your doctor if you have risk factors for heart disease such as high blood pressure, a family history of heart disease, high cholesterol (a type of fat), are overweight, diabetes, smoke cigarettes, are postmenopausal, are a male over 40 years of age; have liver disease; have kidney disease; or have seizures or epilepsy. ? You may not be able to take sumatriptan, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above. Sumatriptan is in the FDA pregnancy category C. This means that it is not known whether sumatriptan will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant or could become pregnant during treatment. Sumatriptan passes into breast milk and may affect a nursing infant. Do not take sumatriptan without first talking to your doctor if you are breast-feeding a baby.

How To Use
Take sumatriptan tablets exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water. Take one tablet as soon as you notice symptoms of a migraine, or at any time during an attack. If your symptoms go away, but then return, you can take additional doses as needed every 2 hours, up to a maximum of 300 mg in 24 hours, unless otherwise directed by your doctor. Never take more than this amount. If your symptoms do not improve at all, call your doctor before taking any more doses of sumatriptan. More medication will not further treat symptoms. Store sumatriptan at room temperature away from moisture, heat, light, and the reach of children. Throw away any unused medicine on the expiration date.

Missed Dose
Since sumatriptan is taken to treat migraines or cluster headaches as they occur and not to prevent them, missing a dose is not a problem. Take only the doses you need, according to your doctor's instructions.

Over Dose
Seek emergency medical attention. Symptoms of a sumatriptan overdose might include tremor, redness, or a warm feeling in your arms and legs, irregular breathing, large pupils; an uncoordinated feeling; and chest pain.

Side Effects
If you experience any of the following serious side effects, stop taking sumatriptan and seek emergency medical attention: an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives); or severe or prolonged chest pain or an irregular heartbeat. Other, less serious side effects may be more likely to occur. Continue to take sumatriptan and talk to your doctor if you experience nausea; drowsiness or di

Precautions
? Do not take sumatriptan if the headache you are experiencing is not like other migraines that you have had.