Why is Imitrex prescribed?
Imitrex is prescribed for the treatment of a migraine attack with or without the presence of an aura (visual disturbances, usually sensations of halos or flickering lights, which precede an attack). The injectable form is also used to relieve cluster headache attacks. (Cluster headaches come on in waves, then disappear for long periods of time. They are limited to one side of the head, and occur mainly in men.)
Imitrex cuts headaches short. It will not reduce the number of attacks you experience.
Most important fact about Imitrex
Imitrex should be used only to treat an acute, classic migraine attack or a cluster headache. It should not be used for certain unusual types of migraine.
How should you take Imitrex?
Imitrex should be taken as soon as your symptoms appear, but may be used at any time during an attack. It is available in three forms: injection, tablets, and nasal spray.
Imitrex injection is administered just below the skin with an autoinjector (self-injection device). Choose a site where the skin is thick enough to take the full length of the needle (1/4 inch). Avoid injecting Imitrex into a muscle or a vein. Your doctor should instruct you on how to use the autoinjector and how to dispose of the empty syringes. You should also read the instruction pamphlet that comes with the medication.
You can take a second injection if your headache returns; however, never take more than 2 injections within 24 hours, and be sure to wait 1 hour between doses.
Imitrex tablets should be swallowed whole, with liquid. If you have had no relief 2 hours after taking Imitrex Tablets, you may take a second dose of up to 100 milligrams, if your doctor advises it. If the headache returns, you may take additional doses at intervals of at least 2 hours. You should not take more than 300 milligrams in one day. If your headache returns after you have had an Imitrex Injection, you may take single Imitrex Tablets, at intervals of at least 2 hours, up to a maximum of 200 milligrams in a day.
Imitrex nasal spray is packaged in single-dose bottles containing either 5 or 20 milligrams of the drug. The usual dosage is a single spray in one nostril. If the headache returns, you may repeat the dose once after 2 hours. Do not take more than 40 milligrams a day.
--If you miss a dose...
Imitrex is not for regular use. Take it only during an attack.
--Storage instructions...
Store Imitrex away from heat and light, at room temperature, in the case provided. If your medication has expired (the expiration date is printed on the treatment pack), throw it away as instructed, but keep the autoinjector. If your doctor decides to stop your treatment, do not keep any leftover medicine unless your doctor tells you to. Throw away your medicine as instructed.
What side effects may occur?
Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Imitrex.
• More common side effects may include:
Burning sensation, dizziness or vertigo, feeling of heaviness, feeling of tightness, flushing, mouth and tongue discomfort, muscle weakness, nausea (nasal spray), neck pain and stiffness, numbness, pressure sensation, redness at the site of injection, sinus or nasal discomfort (nasal spray), sore throat, tingling, unusual taste (nasal spray), vomiting (nasal spray), warm/cold sensation
In addition to the above side effects, people taking Imitrex for cluster headache may experience nausea, a "pins and needles" sensation, vomiting, or wheezing.
Why should Imitrex not be prescribed?
Imitrex should not be used for the hemiplegic or basilar forms of migraine. You must also avoid Imitrex if it gives you an allergic reaction.
In addition, the drug should not be prescribed if you have certain types of heart or blood vessel disease, including angina (crushing chest pain) or a history of heart attack, stroke, mini-strokes, or other circulatory problems. It should not be used if you have severe liver disease or uncontrolled high blood pressure. It must not be used within 24 hours of taking an ergotamine-based migraine remedy (such as D.H.E. 45 Injection or Sansert) or any drug in the same class as Imitrex (such as Amerge, Maxalt, or Zomig). And it must not be used for 2 weeks after taking an MAO inhibitor drug such as the antidepressants Nardil and Parnate.
Special warnings about Imitrex
Although the danger is minimal, Imitrex has triggered serious heart problems in people with heart disease. For that reason, the doctor may want you to take your first dose of Imitrex in the office, where you can be closely watched for ill effects.
Be sure to tell the doctor if you have any conditions that increase your risk of heart disease, such as high blood pressure, high cholesterol, or diabetes. Also let him know if you smoke, have heart disease in the family, or have gone through menopause. Patients at risk of heart disease should have periodic cardiac evaluations as long as they continue using Imitrex. If you develop pain or tightness in the chest, throat, or jaw after taking a dose, consult your doctor before taking any more.
If you develop severe chest pain, call the doctor immediately. Also seek immediate attention if you suffer sudden, severe abdominal pain after a dose of Imitrex. It could signal a blood vessel problem.
Be careful not to inject Imitrex into a vein. This can cause a serious heart irregularity.
If your fingers turn pale, then blue, after a dose of Imitrex, you may have a circulatory problem such as hardening of the arteries. Be sure to let your doctor know.
This medication should not be used for other types of migraine headache. If the first dose does not relieve your symptoms, your doctor will re-evaluate you; you may not have migraine or cluster headache.
If your headache does not feel like any you have been experiencing, do not take Imitrex.
Use Imitrex cautiously if you have liver or kidney disease. Also, if you have any trouble with your eyes, tell your doctor.
Imitrex is not recommended for adults over 65. It has not been tested in children.
Although very rare, severe and even fatal allergic reactions have occurred in people taking Imitrex. Such reactions are more likely in people who have several allergies.
In rare cases, people have suffered seizures after taking Imitrex. Use the drug with caution if you have epilepsy or any condition that increases your risk of having a seizure.
Possible food and drug interactions when taking Imitrex
If Imitrex is taken with certain other drugs, the effects of either may be increased, decreased, or altered. It is important to check with your doctor before combining Imitrex with the following:

Drugs classified as MAO inhibitors, including the antidepressants Nardil and Parnate
Ergot-containing drugs such as Cafergot and Ergostat
Fluoxetine (Prozac)
Fluvoxamine (Luvox)
Paroxetine (Paxil)
Sertraline (Zoloft)
Special information if you are pregnant or breastfeeding
The effects of Imitrex during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, inform your doctor immediately. Imitrex does appear in breast milk and could affect a nursing infant. If Imitrex is essential to your health, your doctor may advise you to discontinue breastfeeding until your treatment with Imitrex is finished.
Recommended dosage
IMITREX INJECTION
The maximum single recommended adult dose is 6 milligrams injected under the skin.
The maximum recommended dose that may be given within 24 hours is two 6 milligram injections taken at least 1 hour apart.
IMITREX TABLETS
The usual adult dose is one 25-, 50-, or 100-milligram tablet taken with water or other liquid. The most you should take at one time is 100 milligrams, and the most you should take in 1 day is 200 milligrams. Doses should be spaced at least 2 hours apart.
If you have liver disease, you should not take more than 50 milligrams of Imitrex Tablets at one time.
IMITREX NASAL SPRAY
The recommended adult dose ranges from 5 to 20 milligrams taken when the attack begins and repeated once, if necessary, 2 hours later. Doses are usually taken as a single spray in one nostril, but if a 10-milligram dose works best for you, you can take it as a 5-milligram spray in each nostril. Do not use more than 20 milligrams at a time, or take more than 40 milligrams a day.
Overdosage
Any medication taken in excess can have serious consequences. If you suspect an overdose, seek medical attention immediately.
• Symptoms of Imitrex overdose may include:
Bluish tinge to the skin, convulsions, dilated pupils, inactivity, lack of coordination, paralysis, redness in the arms and legs, skin changes at the site of injection, slow breathing, sluggishness, tremor