Ghosh, S., & Dey, S. (2010). Comparing different antiemetic regimens for chemotherapy induced nausea and vomiting. International Journal of Collaborative Research on Internal Medicine and Public Health, 2, 142–156. 

To compare the efficacy and safety of ondansetron, granisetron, and palonosetron used with equal dosage of dexamethasone with moderately emetogenic chemotherapy (MEC) to highly emetogenic chemotherapy (HEC)

• Patients were assigned randomly to receive either 8 mg ondansetron on days 1 and 2, 3 mg granisetron on days 1 and 2, or 0.75 mg palonosetron on day 1, 30 minutes prior to chemotherapy.
• All patients received 16 mg of IV dexamethasone on day 1, and 4 mg on days 2 and 3.
• Patients were followed for 5 days for efficacy and 8 days for safety evaluation.

• The study consisted of 1,213 participants.
• The ondansetron arm had 616 participants, the granisetron arm had 440 participants, and the palonosetron arm had 157 participants. 
• Median age was 64 years old.
• More than half of the group was female (54.2%).
• Diagnoses were not reported. 
• More than three-fourths of the group (76%) had received prior chemotherapy.
• Patients receiving HEC regiments, chiefly involving use of cisplatin, represented 40% of the sample. The rest of the sample were receiving MEC regimens, including lower-dose cyclophosphamide and doxorubicin.

The study was conducted in a single outpatient setting at Bankura Smmilani Medical College and Hospital in India.

All patients were in active treatment.

This was a double-blind, randomized controlled trial.

• Complete response (CR) was defined as no emetic episodes, no rescue medication use, and no more than mild nausea.
• Partial response (PR) was defined as less than one vomiting episode or moderate nausea for a maximum of four hours.
• Treatment failure was defined as two or more vomiting episodes, severe nausea, or nausea lasting more than hours.
• The method of rating nausea severity was not described.
• The method for data capture was not described.

• No significant differences were found between groups in antiemetic side effects.
• Overall, across both HEC and MEC groups, palonosetron was found to be the best acting drug (87.8% CR), following by ondansetron (77.2% CR) and granisetron (76.6% CR) (p = 0.021).
• In the HEC group, no differences were found in antiemetic response across the treatment groups.
• Within the first 24 hours, in the MEC group, among those receiving palonosetron, 92.5% had CR, compared to 83.6% of those receiving granisetron and 76.8% receiving ondansetron (p = 0.01).
• Palonosetron also was slightly more effective in the delayed phase of nausea and vomiting (p = 0.02).
• Headache and constipation were the most common side effects.

• For patients receiving MEC, palonosetron was more effective than granisetron and ondansetron for the prevention and control of chemotherapy-induced nausea and vomiting (CINV) in the acute phase.
• No significant differences were found in efficacy for patients receiving HEC.

• Limited information about diagnostic information was provided, and no subgroup analysis was conducted for those who were chemotherapy naïve versus those who had received prior emetogenic therapy.
• No description was provided of the actual methods for data collection used, and no description was provided regarding how nausea severity was measured.

Study findings suggest that palonosetron may be more effective for CINV prevention and control with MEC. Palonosetron, as pointed out in this article, is much more expensive than the other medications used, so considering its use in the type of chemotherapy treatment where it appears to be more effective makes sense. Differences in efficacy seen over time suggest that the same drug may have the same efficacy in a patient over the course of therapy. Consideration might be given to studying this issue and the potential of switching drugs at various points.