A combination of Marinol® and prochlorperazine is an effective antiemetic regimen for treatment of chemotherapy-induced nausea and vomiting, according to results from a study reported in the Journal of Pain and Symptom Management.

Nausea and vomiting are common side effects of chemotherapy treatment and can cause great discomfort and dehydration. In some patients, nausea and vomiting can be so severe that chemotherapy doses may need to be reduced or delayed, resulting in the delivery of sub-optimal treatment. As a result, it is imperative to prevent or manage nausea and vomiting so that patients receive optimal treatment for their cancer.

Nausea and vomiting are typically managed with one or several antiemetics, such as 5HT3 inhibitors, prochlorperazine, metoclopramide, or dexamethasone. Often, physicians will use combinations of antiemetics that prevent nausea and vomiting from occurring in different ways. These combinations are typically more effective than single agents.

Marinol® is part of a class of drugs collectively referred to as cannabinoids. Marinol® is believed to directly block the cannabinoid-1 receptor in the brain that is responsible for chemotherapy-induced nausea and vomiting. Additionally, Marinol® is also known to be an appetite stimulant. The dual role of preventing nausea and vomiting and stimulating appetite to prevent weight loss may be beneficial to patients receiving chemotherapy treatment.

In a multi-center, double-blind, randomized clinical trial, researchers compared the efficacy and toxicity of Marinol® and prochlorperazine, utilized alone and in combination, for the management of chemotherapy-induced nausea and vomiting. The study involved 60 patients who received either 1) Marinol® plus placebo; 2) prochlorperazine plus placebo; or 3) Marinol® plus prochlorperazine. The patients began antiemetic treatment 24 hours prior to chemotherapy and continued for 24 hours after the last dose of chemotherapy.

The results indicated that only 29% of the patients who received the combination of Marinol® plus prochlorperazine experienced nausea and 35% experienced vomiting. In contrast, 47% of patients who received Marinol® alone experienced nausea, with 41% experiencing vomiting and 60% of patients who received prochlorperazine alone experienced nausea, with 55% experiencing vomiting.

These results indicate that the combination of Marinol® and prochlorperazine was significantly more effective than either single agent in controlling chemotherapy-induced nausea and vomiting. Furthermore, Marinol® appeared more effective than prochlorperazine when used alone. The researchers concluded that the combination of Marinol® and prochlorperazine was an effective antiemetic regimen for the management of chemotherapy-induced nausea and vomiting. ( Journal of Pain and Symptom Management, Vol. 6, No. 6, pp. 352-359, 1991)