Imitrex is used for:
The treatment of migraine headaches with or without aura (eg, flashing lights, wavy lines, dark spots). It is also used to treat cluster headaches.

Imitrex is a serotonin 5-HT 1 receptor agonist ("triptan"). It works by narrowing blood vessels in the brain, which helps to relieve migraine and cluster headaches.

Do NOT use Imitrex if:
you are allergic to any ingredient in Imitrex
you have a history of ischemic heart disease (eg, angina, heart attack), coronary artery disease (CAD), other moderate to severe heart problems, brain blood vessel disease (eg, stroke, transient ischemic attack), or other blood vessel disease (eg, Raynaud syndrome, ischemic bowel disease)
you have uncontrolled high blood pressure or severe liver problems
you have certain types of migraines (eg, hemiplegic, basilar)
you have used certain other migraine medicines within the past 24 hours (eg, an ergot derivative [eg, dihydroergotamine, methysergide], another serotonin 5-HT 1 receptor agonist [eg, eletriptan, rizatriptan])
you are taking sibutramine

Contact your doctor or health care provider right away if any of these apply to you.

Before using Imitrex :
Some medical conditions may interact with Imitrex . Tell your health care provider if you have any medical conditions, especially if any of the following apply to you:
if you are pregnant, planning to become pregnant, or are breast-feeding
if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
if you have allergies to medicines, foods, or other substances
if you have history of liver or kidney problems, seizures (eg epilepsy), or heart problems
if you have shortness of breath, chest pain, or a history of high blood pressure, heart attack, stroke, high cholesterol, diabetes, or smoking
if you are a woman who is past menopause
if you are a man who is more than 40 years old
if you are very overweight
if a family member has had heart disease

Some MEDICINES MAY INTERACT with Imitrex . Tell your health care provider if you are taking any other medicines, especially any of the following:
Selective serotonin reuptake inhibitors (SSRIs) (eg, fluoxetine), serotonin norepinephrine reuptake inhibitors (SNRIs) (eg, duloxetine), orsibutramine because the risk of a serious side effect called serotonin syndrome may be increased. Symptoms of serotonin syndrome may include mental or mood changes, hallucinations, fast heartbeat, fever, loss of coordination, muscle spasms, increased sweating, nausea, vomiting, or diarrhea
Monoamine oxidase inhibitors (MAOIs) (eg, phenelzine) because they may increase the risk of Imitrex 's side effects
Ergot derivatives (eg, dihydroergotamine, methysergide) or other serotonin 5-HT 1 receptor agonists (eg, eletriptan, rizatriptan) because the risk of their side effects may be increased by Imitrex

This may not be a complete list of all interactions that may occur. Ask your health care provider if Imitrex may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Imitrex :
Use Imitrex as directed by your doctor. Check the label on the medicine for exact dosing instructions.
An extra patient leaflet is available with Imitrex . Talk to your pharmacist if you have questions about this information.
A health care provider will teach you how to use Imitrex . Be sure you understand how to use Imitrex . Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.
Do not use Imitrex if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.
Inject Imitrex just under the skin. Do NOT inject Imitrex into a muscle or a blood vessel. Talk with your health care provider about suitable injection sites, how to load an autoinjector device, and how to give an injection.
Imitrex will relieve migraine pain at any time during an attack. It is best to inject a dose of Imitrex as soon as you notice symptoms of a migraine attack.
If your migraine symptoms go away and then come back, you may use a second dose as directed by your doctor. Wait at least 1 hour between doses.
If your symptoms do not improve after the first injection, do not use a second dose for the same attack. Contact your doctor.
Do not use more than 2 doses in a 24-hour period or treat more than 4 headaches within 30 days without checking with your doctor.
Do not throw away the autoinjector.
Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.
If you miss a dose of Imitrex and you still have a headache, follow your doctor's dosing instructions. Contact your doctor if you are unsure of what to do if you miss a dose. Do not use Imitrex more often than prescribed. Do not use 2 doses at once.

Ask your health care provider any questions you may have about how to use Imitrex .

Important safety information:
Imitrex may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Imitrex with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
Overuse of Imitrex can cause your headache to become worse. Do NOT take more than the recommended dose or use more often than prescribed without checking with your doctor.
Rarely, serious heart problems (eg, heart attack, irregular heartbeat) have been reported within a few hours of using Imitrex . Contact your doctor at once if fast or irregular heartbeat; chest, jaw, or neck pain or numbness; numbness of an arm or leg; severe stomach pain, dizziness, or vomiting; fainting; or vision changes occur. Discuss any questions or concerns with your doctor.
Serotonin syndrome is a possibly fatal syndrome that can be caused by Imitrex . Your risk may be greater if you take Imitrex with certain other medicines (eg, SSRIs, SNRIs). Symptoms may include agitation; confusion; hallucinations; coma; fever; fast or irregular heartbeat; tremor; excessive sweating; and nausea, vomiting, or diarrhea. Contact your doctor at once if you have any of these symptoms.
Imitrex should not be used to prevent or reduce the number of migraine headaches you have. If you have a headache that is different than your usual migraine headaches, check with your doctor before using Imitrex .
Do NOT use more than the recommended dose without checking with your doctor.
Lab tests, including heart function tests, may be performed while you use Imitrex . These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
Imitrex should not be used in the ELDERLY; the risk of serious side effects (eg, heart problems, high blood pressure) may be increased.
Imitrex should not be used in CHILDREN younger than 18 years old; safety and effectiveness in these children have not been confirmed.
PREGNANCY and BREAST-FEEDING: It is not known if Imitrex can cause harm to the fetus. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Imitrex while you are pregnant. Imitrex is found in breast milk. If you are or will be breast-feeding while you use Imitrex , check with your doctor. Discuss any possible risks to your baby.

Possible side effects of Imitrex :
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Burning, numbness, or tingling of the skin; dizziness; drowsiness; feeling of heaviness, pressure, or tightness; feeling strange; mild, temporary flushing; muscle aches; nausea; neck stiffness; pain, swelling, or redness at the injection site; sick feeling; throat or sinus discomfort; tight feeling in the head; tingling; tiredness; vomiting; warm/hot sensation; weakness.
Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); bloody diarrhea; chest pain; confusion; fainting; fast or irregular heartbeat; fever; hallucinations; hearing problems; numbness or tingling of an arm or leg; one-sided weakness; pain, tightness, or pressure in the jaw, neck, or chest; seizures; severe headache, dizziness, or vomiting; severe or prolonged flushing; severe stomach pain; shortness of breath; speech changes; very cold or blue fingers or toes; vision changes or loss of vision; wheezing.