What is the primary use of antiemetics in patients undergoing cancer treatment?

Antiemetics are primarily utilized in the context of cancer treatment to manage nausea and vomiting, which are common side effects associated with chemotherapy and radiation therapy. These episodes can significantly affect a patient's quality of life, leading to decreased adherence to treatment plans and overall distress.

By administering antiemetics, healthcare providers can help mitigate these gastrointestinal symptoms, thereby enabling patients to tolerate their treatment better and maintain their nutritional intake. Effective control of nausea and vomiting is crucial, as it not only improves the patient's comfort but also reduces the risk of dehydration and malnutrition, which can complicate cancer treatment further.

The other options pertain to different medical issues that are not directly related to the primary applications of antiemetics in a cancer treatment setting.