A nurse is providing education to a client who has migraine headaches and has a new prescription for sumatriptan (Imitrex). Which manifestations Indicate a possible adverse reaction that the nurse should instruct the client to stop taking the medication and notify the provider?

A. Indigestion is not a severe side effect, although it can be uncomfortable; it is not an indication to stop the medication. B. Weight gain is not a common or serious adverse effect of sumatriptan. C. Persistent chest pain is a serious adverse effect of sumatriptan, as it can indicate a cardiovascular event such as angina or a heart attack. The client should stop taking the medication and seek immediate medical attention. D. Nausea may occur with sumatriptan use but is not a serious adverse effect unless it is accompanied by other severe symptoms.