 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST] . Many people using this medication do not have serious side effects. This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high. Sumatriptan can commonly cause chest/jaw/neck tightness, pain, or pressure that is usually not serious. However, these side effects are like symptoms of a heart attack, which may include chest/jaw/left arm pain, shortness of breath, or unusual sweating. Get medical help right away if these or other serious side effects occur, including: fast/irregular heartbeat, fainting, severe stomach/abdominal pain, bloody diarrhea, signs of a stroke (such as weakness on one side of the body, trouble speaking, sudden vision changes, confusion). Tell your doctor right away if you have any serious side effects, including: blue fingers/toes/nails, cold sensation of hands/feet, hearing changes, mental/mood changes, seizures. This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right </s>