If you have any of the following conditions you should not take imitrex: allergy to Imitrex, Raynaud syndrome, strokes in the past, certain types of heart disease, transient ischemic attacks, uncontrolled blood pressure, peripheral vascular disease. You should consult your personal doctor before taking this medicine if you smoke, have high cholesterole or high blood pressure, diabetes.

The following side effects can occur when taking imitrex: dizziness, nausea, fatigue, drowsiness

If you experience any of the following serious side effects, stop using sumatriptan and seek emergency medical attention: an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives); severe or prolonged chest pain or an irregular heartbeat; chest, jaw, or neck pain or tightness; sudden or severe stomach pain; problems seeing; or unusual weakness or numbness. Other, less serious side effects may be more likely to occur. Continue to use sumatriptan and talk to your doctor if you experience nausea; drowsiness or dizziness; tingling, flushing, warmth, redness, or heaviness of a body part; unpleasant taste in the mouth (nasal spray); nasal irritation (nasal spray); or injection site discomfort (injection). Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.