Which of the following is NOT a common side effect of metoclopramide?

Metoclopramide is a medication commonly used to treat conditions like gastroparesis and to prevent nausea and vomiting, particularly in the context of chemotherapy or postoperative scenarios. Among its side effects, drowsiness, diarrhea, and tardive dyskinesia are indeed recognized as common adverse reactions.

Drowsiness is a frequent issue due to metoclopramide's central nervous system effects. Diarrhea can occur as a result of increased gastrointestinal motility. Tardive dyskinesia, while a serious potential side effect, is associated with long-term use of the medication, due to its dopamine antagonist properties.

In contrast, hypertension is not typically a side effect associated with metoclopramide. It does not have a direct impact on blood pressure regulation in the same way that other medications might. Therefore, identifying hypertension as the option that is not commonly associated with metoclopramide is accurate, as it stands apart from the other stated side effects, which are more likely to occur during treatment.