A client with chemotherapy induced nausea receives a prescription for metoclopramide. Which adverse effect is most important for the nurse to report?

A) Diarrhea: While diarrhea can be a side effect of metoclopramide, it is generally less concerning than other potential adverse effects. It may require monitoring but does not typically warrant immediate reporting unless it is severe or persistent. B) Involuntary movements: This symptom is critical to report because metoclopramide can cause extrapyramidal symptoms, including tardive dyskinesia or acute dystonic reactions. These involuntary movements can be serious and may indicate a need for medication adjustment or discontinuation, making it imperative for the nurse to communicate this finding to the healthcare provider immediately. C) Unusual irritability: While irritability may be noted, it is less specific and concerning than the potential for involuntary movements. Although it can affect the client’s overall well-being, it does not indicate a severe or immediate risk to the client's health. D) Nausea: As the medication is intended to alleviate nausea, reporting nausea would not be appropriate unless it is persistent or severe. It would be expected for a client receiving this medication to have some residual nausea, but it should be assessed in the context of the overall treatment plan.