Kawazoe, H., Motoki, Y., Takechi, Y., Shishino, Y., Ido, K., Suemaru, K., & Araki, H. (2010). Comparison of antiemetic efficacy between single and repeat treatment with dexamethasone in patients receiving carboplatin-based combination chemotherapy. Methods and Findings in Experimental and Clinical Pharmacology, 32(7), 499-505.

To assess the preventive effects of single and repeat treatment with dexamethasone on delayed nausea and vomiting in patients receiving carboplatin-based chemotherapy

• The study was carried out using the Ehime University Hospital electronic health record.
• It consisted of 64 patients with various malignancies who had been treated with carboplatin-based combination chemotherapy. 
• Chemotherapy-induced nausea and vomiting (CINV) assessment was conducted three times a day for the first five days after the chemotherapy cycle began, using the nausea and emesis score and food intake score.  
• The frequency of need for rescue antiemetics also was assessed.

• The study consisted of 64 patients.
• The mean age was 59 years for the Repeat Treatment group and 62 years for the Single Treatment group. 
• Race was not included in the sample description.
• Just over half of the patients were male (57%).
• Patients were diagnosed primarily with lung and ovarian cancers.
• Patients were excluded if they had complications such as brain metastases that might induce nausea or vomiting, hepatic failure, or ulcerative diseases; were receiving drugs that affect nausea and vomiting (e.g., major or minor tranquilizers, corticosteroids given for other reasons than prevention of CINV); were receiving concomitant radiation therapy; or were receiving total parenteral nutrition (TPN).

This was a single-site study conducted at an inpatient setting in Ehime, Japan.

• All patients were in active treatment.
• The study has applications for late effects and survivorship.

This was a retrospective, observational study.

• Nausea and emesis was rated on a five-point scale (1 = absent,  3 = nausea, 5 = emesis).
• Food intake was rated on a five-point scale (5 = complete intake, 3 = partial meal, 1 = missed meal because of nausea and vomiting).
• Frequency of need for rescue antiemetics was recorded.

• Demographic data was very different for the two groups. The Repeat Treatment Group was comprised of all women with gynecologic cancers. The Single Treatment group was mostly lung cancer, and 71% of the group were male. Data from both groups demonstrated that nausea and vomiting was well controlled on Day 1. The Single Treatment group received almost all placlitaxel, while the Repeat Treatment Group received docetaxel. No patients in the Single Treatment group experienced emesis, and only two subjects experienced emesis in the Repeat Treatment group.
• A significant negative correlation was found between the total nausea and vomiting scores and food intake scores on days 2–5.
• Almost half of the patients (45%) required antiemetics. The frequency of need for rescue antiemetics overall was significantly less in the Repeat Treatment group (26.9%) compared to the Single Treatment group (57.9%).
• Overall response was 0.268 (CI = 0.091–0.789, p = 0.015).

• The authors stated that repeat treatment of dexamethasone may be more effective than single-dose dexamethasone for prevention of delayed CINV (after 24 hours) for patients treated with carboplatin-based combination chemotherapy.
• The Repeat Treatment Group, which consisted of all women treated with multiple doses of dexamethasone, experienced less delayed CINV, as defined by the need for rescue antiemetics.
• Results would need to be confirmed in a larger, prospective clinical trial.

• This retrospective study design relied on the accurate documentation of events by others.
• This study had a small sample size of 64 subjects, with even smaller groups for comparison study.
• The groups were not heterogenous, making comparison difficult. The only constant was the use of carboplatin-based combination chemotherapy.
• All patients were not chemotherapy naïve. History of previous CINV, smoking history, or motion sickness was not described.
• Measurement scales combining nausea and vomiting are not precise enough to know magnitude of nausea.

Patients treated with carboplatin-based combination chemotherapy may benefit from a daily dose of dexamethasone for three days following initiation of chemotherapy.