What is the interaction between Remeron (Mirtazapine) and Marinol (Dronabinol)?

From the Guidelines

Remeron (mirtazapine) and Marinol (dronabinol) can be used together with caution, but patients should be aware of potential interactions, as evidenced by the most recent guidelines 1. When considering the use of Remeron and Marinol together, it's essential to weigh the potential benefits against the risks. Remeron, an antidepressant, can help with sleep and appetite, while Marinol, a synthetic cannabinoid, is used for nausea, vomiting, and appetite stimulation.

Key Considerations

• Both medications can cause central nervous system depression, potentially leading to increased sedation, dizziness, and cognitive impairment when combined 1.
• Patients should avoid alcohol and other CNS depressants, and should not drive or operate machinery until they know how this combination affects them.
• Starting with lower doses of each medication and gradually increasing as tolerated under medical supervision is recommended.
• The combination might be particularly beneficial in patients needing both mood support and appetite stimulation, such as those undergoing cancer treatment, but requires careful monitoring by healthcare providers for side effects and effectiveness 1.

Evidence-Based Recommendations

• A recent study found that megestrol acetate was superior to dronabinol in promoting weight gain and appetite in patients with advanced cancer 1.
• However, dronabinol did improve appetite and weight gain in some study patients, suggesting that it could be helpful for some patients with cancer-related anorexia 1.
• Ultimately, the decision to use Remeron and Marinol together should be made on a case-by-case basis, taking into account the individual patient's needs and medical history, as well as the potential risks and benefits of the combination 1.

From the FDA Drug Label

DRUG INTERACTIONS • Inhibitors and inducers of CYP2C9 and CYP3A4: May alter dronabinol systemic exposure; monitor for potential dronabinol-related adverse reactions or loss of efficacy. (7.3) • Highly protein-bound drugs: Potential for displacement of other drugs from plasma proteins; monitor for adverse reactions to concomitant highly protein-bound drugs and narrow therapeutic index drugs (e.g., warfarin, cyclosporine, amphotericin B) when initiating or increasing the dosage of dronabinol capsules. (7.4)

The interaction between Remeron (mirtazapine) and Marinol (dronabinol) is not directly addressed in the provided drug label. However, mirtazapine is known to be a highly protein-bound drug.

• Potential interaction: Displacement of mirtazapine from plasma proteins by dronabinol, which may lead to increased risk of adverse reactions.
• Monitoring is recommended when concomitantly administering dronabinol with highly protein-bound drugs like mirtazapine 2.

From the Research

Remeron and Marinol

• Remeron, also known as mirtazapine, is an antidepressant that has been studied for its potential to prevent nausea and vomiting in patients undergoing chemotherapy 3, 4.
• Marinol, also known as dronabinol, is a cannabinoid that has been used to treat nausea and vomiting in cancer patients, particularly those who have not responded to other antiemetic medications 5.
• Studies have shown that mirtazapine can be effective in preventing delayed nausea and vomiting in patients receiving highly emetogenic chemotherapy 3, 4.
• Dronabinol has been shown to be effective in treating chemotherapy-induced nausea and vomiting that is unresponsive to other antiemetics 5.
• Mirtazapine has also been studied for its potential to treat other symptoms in cancer patients, including insomnia and depression 6.

Comparison of Remeron and Marinol

• Both mirtazapine and dronabinol have been shown to be effective in treating nausea and vomiting in cancer patients, but they have different mechanisms of action and potential side effects.
• Mirtazapine is an antidepressant that has been shown to have antiemetic properties, while dronabinol is a cannabinoid that has been used to treat nausea and vomiting 3, 4, 5.
• The choice between mirtazapine and dronabinol may depend on the individual patient's symptoms and medical history, as well as the potential side effects and interactions with other medications.

Potential Side Effects

• Mirtazapine has been associated with side effects such as somnolence and weight gain 3, 4.
• Dronabinol has been associated with side effects such as dizziness and confusion 5.
• Patients should be closely monitored for potential side effects and interactions with other medications when taking either mirtazapine or dronabinol.