A nurse on an oncology unit is preparing to administer doxorubicin to a client who has breast cancer. Prior to beginning the infusion, the nurse verifies the client's current cumulative lifetime dose of the medication. For which of the following reasons is this verification necessary?

Choice A reason: Taking only one dose of nitroglycerin is not a good advice, as it may not be enough to relieve the angina pain and prevent a myocardial infarction. Nitroglycerin is a vasodilator that relaxes the blood vessels and improves the blood flow to the heart. The recommended dose is one tablet or spray under the tongue every 5 minutes for up to three doses, or until the pain is relieved. Taking only one dose may compromise the effectiveness of the medication and the safety of the client.

Choice B reason: Asking the provider to prescribe a different medication is not a necessary action, as nitroglycerin is a first-line treatment for stable angina and has proven benefits for reducing mortality and morbidity. Changing the medication may not be appropriate or feasible, as there may not be a suitable alternative that has the same efficacy and safety profile. The client should continue taking nitroglycerin as prescribed, unless the provider decides otherwise.

Choice C reason: Saying that there's nothing that can be done to relieve the headaches is not a true or helpful statement, as there are some measures that can help reduce or prevent the headaches. Headaches are a common and expected side effect of nitroglycerin, as it dilates the blood vessels in the brain and causes increased intracranial pressure. However, the headaches usually subside over time as the body adapts to the medication. The client can also take a mild analgesic, such as acetaminophen or ibuprofen, to relieve the headache, as long as it does not interact with the nitroglycerin or other medications.

Choice D reason: Trying to take a mild analgesic to relieve the headache is a reasonable and appropriate suggestion, as it can help alleviate the discomfort and improve the quality of life of the client. The client should choose an analgesic that is safe and effective, such as acetaminophen or ibuprofen, and follow the directions on the label. The client should also consult the provider or the pharmacist before taking any over-the-counter medications, as some of them may interact with nitroglycerin or other medications. The client should also avoid aspirin, as it may increase the risk of bleeding.

Choice A reason: Bradycardia is not an indication of circulatory overload. Bradycardia is a slow heart rate, usually below 60 beats per minute. Circulatory overload causes the heart to work harder to pump the excess fluid in the blood vessels, which can result in tachycardia, or a fast heart rate, usually above 100 beats per minute.

Choice B reason: Flushing is not an indication of circulatory overload. Flushing is a reddening of the skin, usually due to increased blood flow or inflammation. Circulatory overload causes the blood vessels to constrict and increase the blood pressure, which can result in pallor, or a pale appearance of the skin.

Choice C reason: Vomiting is not an indication of circulatory overload. Vomiting is the forceful expulsion of stomach contents through the mouth, usually due to nausea, infection, or irritation. Circulatory overload does not affect the gastrointestinal system directly, although it may cause abdominal distension or ascites, which is the accumulation of fluid in the abdominal cavity.

Choice D reason: Dyspnea is an indication of circulatory overload. Dyspnea is the sensation of difficulty breathing, usually due to inadequate oxygen delivery to the tissues. Circulatory overload causes the excess fluid in the blood vessels to leak into the lungs, which can result in pulmonary edema, or the accumulation of fluid in the alveoli. This impairs the gas exchange and causes hypoxia, or low oxygen levels in the blood.