Lajolo, P.P., & del Giglio, A. (2007). Skipping day 2 antiemetic medications may improve chemotherapy induced delayed nausea and vomiting control: Results of two pilot phase II trials. Supportive Care in Cancer, 15(3), 343-346.

To evaluate whether skipping day 2 antiemetic medications may improve delayed chemotherapy-induced nausea and vomiting (CINV), based on the hypothesis that repeated consecutive doses of antiemetics may lead to increased accumulation of 5-HT₃ at the presynaptic level in the gastrointestinal (GI) tract, decreasing the activity of the next dose of a 5-HT₃ receptor antagonist (tachyphylaxis)

Patients were given day 1 antiemetics according to American Society of Clinical Oncology (ASCO) guidelines. Patients in Study 1 received 10 mg metochlopramide by mouth every eight hours, 0.05 mg granisetron by mouth four times per day, and 8 mg dexamethasone four times per day on days 2 and 3. In Study 2, patients received the same medications except that no drugs were given on day 2. Patients recorded emetic episodes in diaries and responded to a quality-of-life (QOL) questionnaire at baseline and on day 6.

• The study consisted of 42 chemotherapy-naïve patients over age 18 who were receiving moderately to highly emetogenic chemotherapy (MEC to HEC).
• Patients were excluded from the study if they had abnormally high serum creatinine, bilirubin, or SGPT; if they were pregnant; if they reported vomiting or use of antiemetics 24 hours before the administration of chemotherapy; or if they were receiving radiation therapy. Patients with brain metastasis, GI obstruction, or regular use of corticosteroids or benzodiazepines before the initiation of chemotherapy also were excluded.

The studies were conducted in the hematology and oncology department of a School of Medicine in Brazil.

This research consisted of two pilot studies.

The Functional Living Index of Vomiting (FLIE) was used.

• Each study consisted of 21 patients. No significant differences were found between the two populations in terms of clinical characteristics or chemotherapy emetogenicity.
• Patients who received no antiemetic medications on day 2 had statistically significant complete control of their nausea and vomiting.

Skipping day 2 antiemetic medications does not seem to worsen delayed CINV and may reduce CINV.

Study limitations include the use of a nonrandomized design and the small sample size.