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.
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.
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.
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);
- 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, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting;
- increased blood pressure – severe headache, blurred vision, pounding in your neck or ears, anxiety, nosebleed; 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.