Indications 

Imitrex is a prescription medicine indicated for the acute treatment of migraine with or without aura in adults.  

Classified as a serotonin 5-HT-receptor agonist, Imitrex works by narrowing blood vessels in the head, blocking pain signals to the brain, and inhibiting the release of natural substances that can cause migraine symptoms such as headache pain, nausea, and sensitivity to light and sound. 

Imitrex should only be used if a clear diagnosis of migraine headaches has been established. It is not indicated for prophylactic migraine therapy or for the treatment of cluster headaches. 

Uses and Dosage 

Before taking Imitrex and every time you get a refill, carefully review its medication guide and patient information leaflet. Consult with a physician or pharmacist for any questions or clarifications. 

The dosage of Imitrex is based on an individual’s medical condition and response to treatment. Typically, it is administered without regard to food intake as directed by the doctor, at the first sign of a migraine. 

In the event of partial relief or headache recurrence, a second dose may be taken at least two hours after the initial dose. Nonetheless, consult a doctor before taking a second tablet if symptoms do not improve after the first dose. 

To avoid any potential risks, adhere to the prescribed dosage of Imitrex, which should not exceed 200 milligrams per day. Follow your doctor’s instructions and avoid altering the recommended dosage or frequency of use. 

If there is no improvement in symptoms or if you experience more than four headaches within a month (30 days), contact your doctor. 

Side Effects 

Possible side effects associated with the use of Imitrex are listed below. If any of them persist or worsen, promptly inform your physician or pharmacist. 

Common Side Effects 

• Flushing 
• Tingling sensation 
• Feeling hot or cold 
• Drowsiness 
• Fatigue 
• Weakness 
• Dizziness 
• Upset stomach 
• Diarrhea 
• Nausea 
• Muscle cramps 

Serious Side Effects 

• Pain, constriction, pressure, or weight in the chest, throat, neck, and/or jaw 
• Slow or difficult speech 
• Faintness 
• Breaking out in a cold sweat 
• Shortness of breath 
• Weakness or numbness of an arm or leg 
• Sudden or severe stomach pain 
• Fast, pounding, or irregular heartbeat 
• Bloody diarrhea 
• Vomiting 
• Sudden weight loss 
• Paleness or blue color of fingers and toes 
• Change in vision 
• Seizures 

Call your doctor right away or get emergency medical treatment if you experience any of the serious side effects listed above. 

Allergic Reactions 

Although rare, a severe allergic reaction to Imitrex may occur. If you experience any of the following symptoms below, seek immediate medical attention. 

• Difficulty breathing or swallowing 
• Redness, swelling, or itching of the eyes, face, lips, or throat 
• Rash 
• Hives 
• Severe dizziness 

The side effects of Imitrex listed here are not complete. If any unmentioned side effects arise and cause discomfort, notify your doctor promptly. 

Cautions 

Before taking Imitrex, inform your physician or pharmacist if you have any known hypersensitivities, especially to sumatriptan or any other medications. 

You may want to seek further information from your pharmacist, as this medication may have inactive components that can cause allergic reactions or other complications. 

To determine whether Imitrex is safe for you, disclose your medical history to your doctor, particularly of: 

• Blood circulation problems (e.g., in legs, arms/hands, or stomach) 
• Some forms of headaches (such as hemiplegic or basilar migraine) 
• Cardiac issues (for instance, angina, arrhythmia, history of myocardial infarction) 
• Liver disease 
• Seizures 
• Stroke or “mini-stroke” (transient ischemic attack) 

Inform your doctor and pharmacist of all the medications, including prescription and non-prescription drugs, vitamins, supplements, or herbal products you are taking, as drug interactions may alter medication efficacy or increase the risk of serious side effects. 

Be mindful to inform your doctor if you are currently on any of the antidepressants mentioned below, for they may need to adjust the dosages of your medications or keep a closer eye on you for any potential side effects. 

• Citalopram (Celexa) 
• Desvenlafaxine (Pristiq) 
• Duloxetine (Cymbalta) 
• Escitalopram (Lexapro) 
• Fluoxetine (Prozac, Sarafem) 
• Fluvoxamine (Luvox) 
• Paroxetine (Paxil) 
• Sertraline (Zoloft) 
• Venlafaxine (Effexor) 

Do not take Imitrex if you have taken an MAO inhibitor within the past 14 days, such as: 

• Isocarboxazid 
• Linezolid 
• Methylene blue injection 
• Phenelzine 
• Rasagiline 
• Selegiline 
• Tranylcypromine 

Imitrex may cause drowsiness or dizziness. Refrain from driving or operating machinery until you have a clear understanding of how the medication affects you. 

Inform your doctor if you are pregnant or planning to conceive, as it is uncertain whether Imitrex can cause harm to an unborn baby. 

Before breastfeeding, consult with your doctor as sumatriptan can enter breast milk in minimal quantities.