Marinol (Dronabinol) Dosing for Appetite Stimulation
For appetite stimulation, start dronabinol at 2.5 mg twice daily (one hour before lunch and one hour before dinner), with the option to reduce to 2.5 mg once daily at supper or bedtime if side effects occur. 1
Standard Dosing Protocol
- Initial dose: 2.5 mg twice daily, administered one hour before lunch and one hour before dinner 1
- Dose reduction: If side effects occur (feeling high, dizziness, confusion, somnolence), reduce to 2.5 mg once daily at supper or bedtime 1
- Maximum dose: The FDA label describes the initial 5 mg/day total dose (2.5 mg twice daily) as the standard regimen, with dose reduction as needed 1
Clinical Context and Efficacy
The FDA approval for dronabinol in AIDS-related anorexia demonstrated statistically significant appetite improvement at weeks 4 and 6 compared to placebo, with 38% of patients showing increased appetite above baseline versus 8% for placebo 1, 2. Weight stabilization occurred in dronabinol patients while placebo recipients lost an average of 0.4 kg 1, 2.
Important caveat: Dronabinol is generally considered a second-line or alternative option for appetite stimulation, as megestrol acetate (160-200 mg daily) has more robust evidence as first-line therapy for cancer-related anorexia 3. The National Comprehensive Cancer Network notes that cannabinoids like dronabinol have limited and inconsistent evidence for effectiveness in cancer-related anorexia and are not recommended as first-line therapy 3.
Timing Considerations
- Avoid early morning dosing: Pilot studies showed increased frequency of adverse effects with morning administration compared to later-in-the-day dosing 1
- Optimal timing: Administer doses one hour before meals (lunch and dinner) or as a single evening dose if tolerability is an issue 1
Side Effect Profile
Common side effects include 1, 2:
- Euphoria and feeling high (18% required dose reduction) 1
- Dizziness and confusion 1
- Somnolence 1
- Thinking abnormalities 2
Special population warning: Cannabinoid administration in elderly patients may induce delirium 3. In the geriatric pain management context, dronabinol 2.5 mg once or twice daily is associated with dizziness, somnolence, cognitive impairment, and dysphoria 4.
Comparative Effectiveness
Dronabinol is less effective than megestrol acetate for promoting weight gain (49% vs 75% of patients) and appetite improvement (3% vs 11%) 3. In hospitalized patients, there was no significant difference between dronabinol, megestrol, and mirtazapine for change in meal intake, though numerical improvements of approximately 17% in meal intake were observed across all agents 5.
Duration of Effect
Sustained improvement in appetite was observed in open-label continuation studies after the initial 6-week treatment period 1. However, in patients with advanced malignancy and liver metastases, effects may decrease as disease progresses and general condition worsens 6.