From the Guidelines
Yes, it is acceptable to start a patient on 5mg of dronabinol (Marinol) once daily if the 2.5mg tablets for twice-daily dosing are unavailable, as the total daily dose remains the same (5mg), but the administration schedule changes from 2.5mg twice daily to 5mg once daily. However, patients should be monitored more closely with this regimen as they may experience more pronounced side effects with a single larger dose, such as euphoria, drowsiness, dizziness, vertigo, and hallucinations, as reported in studies 1. Dronabinol has a relatively long half-life, which allows for once-daily dosing, though twice-daily dosing is often preferred initially to minimize adverse effects like dizziness, drowsiness, confusion, and euphoria. When using the once-daily approach, administering the medication in the evening may help patients better tolerate any psychoactive effects.
According to the most recent and highest quality study, the ASCO guideline on cannabis and cannabinoids in adults with cancer 1, oral dronabinol may be started at a 2.5 mg dose and up-titrated as needed, but it also suggests that the medication can be used at a higher dose, up to 10 mg three to four times daily. However, the guideline also emphasizes the importance of monitoring patients closely for adverse effects and adjusting the dose accordingly.
In terms of efficacy, studies have shown 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 strong recommendation 1. Nevertheless, the medication may still be beneficial for some patients, and the decision to start treatment should be made on a case-by-case basis, taking into account the individual patient's needs and medical history.
Key considerations when starting a patient on dronabinol include:
- Monitoring for adverse effects, such as euphoria, drowsiness, dizziness, vertigo, and hallucinations
- Adjusting the dose as needed to minimize adverse effects
- Administering the medication in the evening to help patients better tolerate any psychoactive effects
- Considering alternative treatment options, such as other appetite stimulators or modulators of taste, if dronabinol is not effective or is not well tolerated.
From the FDA Drug Label
The recommended adult starting dosage of dronabinol capsules is 2.5 mg orally twice daily, one hour before lunch and dinner. In elderly patients or patients unable to tolerate 2.5 mg twice daily, consider initiating dronabinol capsules at 2.5 mg once daily one hour before dinner or at bedtime to reduce the risk of central nervous system (CNS) symptoms If CNS adverse reactions of feeling high, dizziness, confusion, and somnolence occur, they usually resolve in 1 to 3 days and usually do not require dosage reduction.
The answer is no, it's not explicitly recommended to start a patient on 5mg of dronabinol once daily if the pharmacy does not have 2.5mg available. The recommended starting dose for adults is 2.5mg twice daily. However, for patients who cannot tolerate this dose, the label suggests initiating dronabinol at 2.5 mg once daily, not 5mg, to reduce the risk of CNS symptoms 2.
From the Research
Dronabinol Dosage
- The available studies do not provide a direct comparison between starting a patient on 5mg of dronabinol once daily versus 2.5mg twice a day 3, 4, 5, 6.
- However, the studies suggest that dronabinol can be effective in stimulating appetite and improving weight gain in various patient populations, including those with HIV infection, cancer, and anorexia of aging 4, 5.
- The efficacy and safety of dronabinol have been evaluated in different dosages and settings, but the optimal dosage and administration schedule are not clearly established 3, 6.
- It is essential to consider the individual patient's needs and medical history when determining the appropriate dosage and administration schedule for dronabinol.
Clinical Considerations
- The decision to start a patient on 5mg of dronabinol once daily instead of 2.5mg twice a day should be based on clinical judgment and consideration of the patient's specific needs and circumstances.
- The patient's response to the medication, including any adverse effects, should be closely monitored and the dosage adjusted as necessary.
- Further research is needed to fully understand the efficacy and safety of dronabinol in different patient populations and to establish optimal dosage and administration guidelines 6.