Objectives: Can addition of neurokinin-1 receptor antagonists (NK1-RAs) be considered as an ideal strategy for the prevention of chemotherapy-induced nausea and vomiting (CINV)? Researchers differ on this question.
Materials and methods: Electronic databases were searched for randomized control trials (RCTs) that evaluated the effectiveness and safety of NK1-RAs in preventing CINV. The primary end point was complete response (CR) in the acute, delayed, and overall phases after chemotherapy. Subgroup analyses evaluated the types of NK1-RAs, routines of administration, types of malignancies, regimens used in combination with NK1-RAs, and age of patients included in the studies. The incidences of different types of adverse events were also extracted to estimate the safety of NK1-RAs.
Results: A total of 38 RCTs involving 13,923 patients were identified. The CR rate of patients receiving NK-RAs was significantly higher than patients in the control groups during overall phase (70.8% vs 56.0%, <0.001), acute phase (85.1% vs 79.6%, <0.001), and delayed phase (71.4% vs 58.2%, <0.001). There were three studies including patients of children or adolescents, the CR rate was also significantly higher in the treatment group (overall phase: OR=2.807, <0.001; acute phase: OR=2.863, P =0.012; delayed phase: OR=2.417, <0.001). For all the other outcomes, patients in the NK1-RAs groups showed improvements compared to the control groups (incidence of nausea: 45.2% vs 45.9%, <0.001; occurrence of vomiting: 22.6% vs 38.9%, <0.001; usage of rescue drugs: 23.5% vs 34.1%, <0.001). The pooled side effects from NK1-RAs did not significantly differ from previous reports and the toxicity rates in patients less than eighteen years old also did not diff between the two groups (P=0.497). However, we found that constipation and insomnia were more common in the patients of control groups, whereas diarrhea and hiccups were more frequently detected in patients receiving NK1-RAs.
Conclusions: NK1-RAs improved the CR rate of CINV. They are effective for both adults and children. The use of NK1-RAs might be associated with the appearance of diarrhea and hiccups, while decreasing the possibility of constipation and insomnia.