A client receives ondansetron prior to a chemotherapy treatment. How should the practical nurse evaluate the effectiveness of the medication?

A. Monitor the client for nausea or vomiting following the treatment: Ondansetron is an antiemetic that works by blocking serotonin receptors in the chemoreceptor trigger zone to prevent nausea and vomiting associated with chemotherapy. Evaluating the absence or reduction of these symptoms after treatment is the best indicator of its effectiveness. B. Determine if the client feels calm and relaxed before the treatment: Assessing calmness relates more to anxiety management than to the pharmacologic effect of ondansetron. This medication does not have anxiolytic properties. C. Observe the client for signs of pain or discomfort during the treatment: Ondansetron does not have analgesic effects. Monitoring pain or discomfort may be necessary for overall care but is unrelated to determining the medication’s effectiveness. D. Assess for changes in vital signs during and after the treatment: Vital signs may provide general information about client status, but they are not reliable indicators of ondansetron’s therapeutic action.