Multiple-day dexamethasone for controlling delayed chemotherapy-induced nausea and vomiting with low-emetic-risk chemotherapy

Chemotherapy-induced nausea and vomiting (CINV) is a distressing adverse effect of chemotherapy that requires aggressive prevention. This study aimed to evaluate the antiemetic efficacy of a 4-day dexamethasone (DEX) regimen compared with the guideline-recommended 1-day DEX regimen against delayed CINV in patients receiving low-emetic-risk chemotherapy (LEC). Pooled patient-level data from a multicenter, prospective, observational study, including 132 patients receiving LEC, divided into 1-day and 4-day DEX groups, were analyzed. An inverse probability of treatment weighting (IPTW) model was applied to balance patient characteristics. The primary endpoint was the incidence of delayed CINV, with secondary endpoints including symptom severity, food intake, and daily incidence patterns. After IPTW adjustment, the incidence of delayed nausea was significantly lower in the 4-day DEX group (3.19%) than in the 1-day group (22.78%, p = 0.001), with no significant difference in acute nausea between the groups (14.49% vs. 5.83%, p = 0.167). In a multivariate model, both female sex and the 1-day DEX regimen were independently associated with a higher risk of delayed CINV. The 4-day DEX group showed favorable trends in nausea incidence, severity, and food intake regardless of the presence of acute CINV. Although 1-day DEX remains the standard approach recommended by antiemetic guidelines, a 4-day DEX regimen shows promise as an alternative strategy for managing delayed nausea, especially in patients who experience acute CINV or have inadequate symptom control.