What is the recommended dose of Marinol (dronabinol) for treating nausea and vomiting or weight loss?

Marinol (Dronabinol) Dosing

For chemotherapy-induced nausea and vomiting in adults who have failed conventional antiemetics, start dronabinol at 5 mg/m² orally 1-3 hours before chemotherapy, then repeat every 2-4 hours after chemotherapy for 4-6 doses per day, with a maximum of 15 mg/m² per dose. 1

For AIDS-related anorexia and weight loss, start dronabinol at 2.5 mg orally twice daily, one hour before lunch and dinner, with a maximum dose of 10 mg twice daily. 1

Chemotherapy-Induced Nausea and Vomiting

Starting Dose

• Begin with 5 mg/m² orally, administered 1-3 hours prior to chemotherapy 1
• Give the first dose on an empty stomach at least 30 minutes before eating; subsequent doses can be taken without regard to meals 1
• Repeat dosing every 2-4 hours after chemotherapy for a total of 4-6 doses per day 1

Dose Titration

• If inadequate response, increase in increments of 2.5 mg/m² per dose based on tolerability 1
• Maximum dose is 15 mg/m² per dose, given 4-6 times daily 1
• Keep timing of doses consistent relative to meals once the effective dose is established 1

Elderly Patients

• Consider starting at 2.5 mg/m² once daily 1-3 hours prior to chemotherapy to reduce CNS adverse effects 1
• If CNS symptoms occur (feeling high, dizziness, confusion, somnolence), reduce to 2.5 mg once daily 1

Important Context

• Dronabinol is indicated only for patients who have failed to respond adequately to conventional antiemetics 1
• Evidence for cannabinoids remains insufficient compared to current standard antiemetic regimens (5-HT3 antagonists, NK1 antagonists, dexamethasone) 2
• When a cannabinoid is chosen for rescue or refractory use, dronabinol or nabilone are the recommended agents over medical marijuana 2
• Combination therapy with dronabinol 10 mg every 6 hours plus prochlorperazine 10 mg every 6 hours was more effective than either agent alone, with only 29% experiencing nausea versus 47% with dronabinol alone 3

AIDS-Related Anorexia and Weight Loss

Starting Dose

• Begin with 2.5 mg orally twice daily, one hour before lunch and dinner 1
• In elderly patients or those unable to tolerate twice-daily dosing, start with 2.5 mg once daily one hour before dinner or at bedtime 1
• Dosing later in the day reduces frequency of CNS adverse reactions 1

Dose Titration

• If tolerated and further effect is desired, increase gradually to 2.5 mg before lunch and 5 mg before dinner 1
• Most patients respond to 2.5 mg twice daily 1
• May further increase to 5 mg before lunch and 5 mg before dinner if needed 1
• Maximum dose is 10 mg twice daily 1

Managing CNS Adverse Effects

• CNS symptoms (feeling high, dizziness, confusion, somnolence) are dose-related and usually resolve in 1-3 days without dose reduction 1
• If CNS symptoms are severe or persistent, reduce to 2.5 mg in the evening or at bedtime 1
• Monitor patients closely and reduce dosage as needed 1

Critical Safety Considerations

Contraindications

• Do not use in patients with hypersensitivity to dronabinol or sesame oil 1
• Reported reactions include lip swelling, hives, disseminated rash, oral lesions, skin burning, flushing, and throat tightness 1

Neuropsychiatric Risks

• Screen patients for history of mania, depression, or schizophrenia before initiating treatment 1
• Avoid use in patients with psychiatric history or monitor closely for new or worsening psychiatric symptoms 1
• Avoid concomitant use with other drugs associated with similar psychiatric effects 1
• Elderly patients are more sensitive to neurological and psychoactive effects 1

Cognitive Impairment

• Dronabinol is associated with cognitive impairment and altered mental state 1
• Reduce dose or discontinue if signs of cognitive impairment develop 1

Practical Considerations

Combination Therapy Benefits

• Adding prochlorperazine to dronabinol decreases the frequency of dysphoric effects seen with dronabinol alone 3
• The combination significantly reduces both nausea incidence (29% vs 47%) and vomiting duration (1 minute vs 2 minutes median per episode) 3

Abuse Potential

• Dronabinol has very low abuse potential with slow onset of action, weak reinforcing effects, and generally dysphoric effects 4
• No evidence of diversion, "doctor-shopping," or street market exists 4

Off-Label Use

• Case reports suggest efficacy for refractory nausea and vomiting from peritoneal carcinomatosis and severe intestinal dysmotility 5, 6
• These uses are not FDA-approved but may be considered when all other modalities have failed 5, 6