Optimization of antiemetic therapy in cancer pharmacotherapy: from guideline implementation to evidence generation and individualized supportive care

Background Chemotherapy-induced nausea and vomiting (CINV) has become less visible than in the early era of cytotoxic chemotherapy, but it remains a clinically meaningful toxicity in cancer pharmacotherapy. Although vomiting is now often preventable with 5-hydroxytryptamine-3 receptor antagonists, neurokinin-1 receptor antagonists, dexamethasone (DEX), and olanzapine (OLZ), nausea, delayed and persistent symptoms, treatment-related burden, and symptoms associated with antibody-drug conjugates and oral anticancer agents remain important clinical challenges. These residual problems require systematic symptom assessment and continued optimization of supportive care in routine practice. Main body This narrative review summarizes major developments in antiemetic therapy and places pharmacist-led and pharmacist-involved clinical studies within the broader international evidence base. The review focuses on evidence underpinning major antiemetic guidelines, randomized phase II and phase III trials, and selected prospective studies that address current questions in practice. Key topics include guideline-consistent prophylaxis, gaps between evidence and routine care, low-dose OLZ, carboplatin-based chemotherapy, DEX-sparing strategies, antibody-drug conjugate-induced nausea and vomiting, oral anticancer agents, patient-reported outcomes, electronic monitoring, and risk-based prophylaxis. Particular attention is paid to how the interpretation of benefit changes when nausea control, total control, treatment burden, daily functioning, and longitudinal symptom patterns are considered. Together, these studies illustrate a practice-to-evidence-to-implementation pathway in which routine clinical observations are translated into multicenter supportive care studies, evidence synthesis, guideline contributions, and individualized care. Conclusion Antiemetic optimization is no longer limited to adding more antiemetic drugs. It includes selecting the appropriate intensity and duration of prophylaxis, reducing avoidable treatment-related burden, extending monitoring beyond 120 h when necessary, and using patient-level risk to guide escalation or de-escalation. Pharmacists can contribute by implementing guideline-based prophylaxis, detecting uncontrolled nausea and vomiting in routine cancer care, designing multicenter supportive care studies, and translating evidence into practical clinical pathways. The central message is that clinical pharmacy can function as a bridge between guideline implementation, patient-reported monitoring, evidence generation, and individualized care.