Antiemetic care for patients with breast cancer: focus on drug interactions and safety concerns.

Purpose: The drug interactions and adverse events that should be considered when individualizing antiemetic therapy for patients undergoing treatment for breast cancer are reviewed.

Summary: A variety of antiemetic agents are available, including antihistamines, dopamine-receptor antagonists, serotonin-receptor antagonists, and neurokinin-receptor antagonists. To ensure optimal symptom control for each patient without unnecessarily prolonging treatment, patient- and treatment-specific risk factors must be considered. Neurokinin-receptor antagonists, the newest class of antiemetics, are effective in preventing acute and delayed chemotherapy-induced nausea and vomiting but must be used in combination with a serotonin-receptor antagonist and a corticosteroid. The serotonin-receptor antagonists have become the mainstay of antiemetic therapy, but current guidelines do not distinguish among the different agents in this class. However, there are distinct pharmacologic differences that may affect the potential for drug interactions and, ultimately, patient outcomes and the occurrence of adverse events. Therefore, the potential for drug interactions must be considered when selecting an antiemetic, particularly for patients who are taking multiple concomitant medications. Further, because a number of breast cancer therapies and some antiemetic agents carry cardiovascular warnings or precautions and since breast cancer patients may already be suffering from cardiovascular complications, the possible cardiotoxic effects of the antiemetic or chemotherapy agents or the combinations of these agents should be considered.

Conclusion: Antiemetic treatment is essential for patients with breast cancer who are undergoing moderately to highly emetogenic cytotoxic treatment. When selecting an antiemetic, clinicians must select an agent that provides optimal protection against nausea and vomiting while avoiding drug-drug interactions and additional adverse events.