From the Guidelines
Marinol is a prescription medication containing dronabinol, a synthetic form of THC, which is FDA-approved for treating nausea and vomiting associated with cancer chemotherapy and for appetite stimulation in patients with AIDS-related weight loss, but its use in cancer-related anorexia/cachexia is not supported by strong evidence 1.
Mechanism of Action and Side Effects
Marinol works by binding to cannabinoid receptors in the brain that control nausea and appetite. Common side effects include dizziness, drowsiness, confusion, and mood changes. Patients should be cautious about driving or operating machinery while taking Marinol due to its psychoactive effects.
Dosage and Administration
Typical dosing for chemotherapy-induced nausea is 5-15 mg/m² taken 1-3 hours before chemotherapy, then every 2-4 hours after chemotherapy for a total of 4-6 doses per day. For appetite stimulation, the usual starting dose is 2.5 mg twice daily before lunch and dinner.
Clinical Evidence
A randomized clinical trial comparing megestrol acetate to dronabinol in treating cancer-associated anorexia revealed megestrol acetate to be superior for promoting weight gain and appetite in patients with advanced cancer 1. Another study found that dronabinol may have the potential to improve chemosensory perception and appetite in patients with cancer anorexia, but the limited and inconsistent evidence does not support a recommendation 1.
Quality of Life and Morbidity
The use of Marinol in cancer-related anorexia/cachexia may have a limited impact on quality of life and morbidity, as the evidence suggests that other treatments, such as megestrol acetate, may be more effective in promoting weight gain and appetite. However, Marinol may still be considered as an option for patients who have not responded to conventional treatments, under the guidance of a healthcare professional.
From the FDA Drug Label
In an open-label study in patients with AIDS who received dronabinol capsules for up to five months, no abuse, diversion or systematic change in personality or social functioning were observed despite the inclusion of a substantial number of patients with a past history of drug abuse Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use. Physical dependence can develop during chronic therapy with dronabinol capsules, and develops after chronic abuse of marijuana A withdrawal syndrome was reported after the abrupt discontinuation of dronabinol in subjects receiving dosages of 210 mg per day for 12 to 16 consecutive days.
Marinol (Dronabinol) Dependence and Withdrawal
- Physical dependence: can develop during chronic therapy with dronabinol capsules.
- Withdrawal symptoms: may occur after abrupt discontinuation of dronabinol, including irritability, insomnia, restlessness, hot flashes, sweating, and anorexia.
- Abuse potential: no abuse or diversion was observed in an open-label study in patients with AIDS who received dronabinol capsules for up to five months, despite the inclusion of patients with a past history of drug abuse 2.
From the Research
Marinol Overview
- Marinol, also known as dronabinol, is a synthetic version of delta-9-tetrahydrocannibinol (delta-9-THC), the active ingredient in cannabis sativa L. (marijuana) 3
- It is an orally active cannabinoid used for the treatment of chemotherapy-induced nausea and vomiting (CINV) in patients with cancer who have failed to respond adequately to conventional antiemetic therapy 4, 3, 5
Efficacy and Pharmacokinetics
- Oral cannabinoids, including dronabinol, have been shown to have similar or improved efficacy compared with conventional antiemetics for the resolution of nausea and/or vomiting in patients with cancer 4
- However, oral THC has high pharmacokinetic variability, with variability in oral dronabinol peak plasma concentrations (C max) estimated between 150 and 200% 4
- A new oral dronabinol solution has decreased intraindividual variability (area under the curve) vs oral dronabinol capsules 4
Clinical Use
- Dronabinol is used for the management of CINV in cancer patients who have failed to respond adequately to conventional antiemetic therapy 6, 3, 5
- It is also used for the treatment of refractory nausea and vomiting unrelated to chemotherapy, such as in patients with peritoneal carcinomatosis 6
- The benefits of dronabinol may extend beyond CINV, as indicated by data from preclinical studies and animal models 5
Adverse Effects
- Oral cannabinoids are associated with a greater incidence of adverse effects compared with conventional antiemetic therapy or placebo, including dizziness, hypotension, and dysphoria or depression 4
- A new formulation of oral cannabinoids (i.e., dronabinol oral solution) may minimize the pharmacokinetic and pharmacodynamic variability currently observed with capsule formulations 4