Reviewed on 5/25/2022

What Is Dronabinol and How Does It Work?

Dronabinol is a prescription medication used to treat loss of appetite in people with AIDS and to treat severe nausea and vomiting caused by cancer chemotherapy

  • Dronabinol is available under the following different brand names: Marinol, Syndros

What Are Dosages of Dronabinol?

Adult and pediatric dosage

Capsule: Schedule III (Marinol)

  • 2.5mg
  • 5mg
  • 10mg

Oral solution: Schedule II (Syndros)

  • 5mg/mL

Chemotherapy-Induced Nausea & Vomiting

Adult dosage

  • Oral capsules: 5 mg/m² orally 1-3 hours before and every 2-4hour after chemotherapy; may be increased in 2.5 mg/m² increments to 15 mg/m²; not to exceed 4-6 doses/day  
  • Oral solution
  • Starting dose: 4.2 mg/m² orally 1-3 hr before chemotherapy, then every 2-4 hours after chemotherapy for a total of 4-6 doses/day
  • Give the first dose on an empty stomach at least 30 minutes before a meal; subsequent doses can be given without regard to meals

Pediatric dosage

Oral capsule

  • 5 mg/m² orally 1-3 hours before and every 2-4hour after chemotherapy; may be increased in 2.5 mg/m² increments to 15 mg/m²; not to exceed 4-6 doses/day.

Geriatric dosage

  • 2.1 mg/m² orally once a day 1-3 hours before chemotherapy to reduce the risk of CNS symptoms


Adult dosage

  • Oral capsules: 2.5 mg orally every 12hour initially, taken right before meals; may be increased to no more than 20 mg/day or decreased to 2.5 mg at bedtime or as needed

Oral solution

  • 2.1 mg orally twice a day, 1 hour before lunch and 1 hour before dinner Dosing later in the day may reduce the frequency of CNS adverse reactions
  • If CNS adverse reactions of feeling high, dizziness, confusion, and somnolence occur, they usually resolve in 1-3 days and usually do not require dosage reduction
  • If CNS adverse reactions are severe or persistent, reduce the dose to 2.1 mg once a day 1 hour before dinner or in the evening at bedtime

Dosage Considerations – Should be Given as Follows: 

  • See “Dosages”


What is HIV? See Answer

What Are Side Effects Associated with Using Dronabinol?

Common side effects of Dronabinol include:

  • mood changes,
  • dizziness,
  • drowsiness,
  • confusion,
  • trouble concentrating,
  • feeling "high,"
  • warmth or tingly feeling,
  • an exaggerated sense of well-being,
  • anxiety,
  • lightheadedness,
  • headache,
  • red eyes,
  • dry mouth,
  • nausea,
  • vomiting,
  • stomach or abdominal pain,
  • diarrhea,
  • sleep problems (insomnia),
  • clumsiness,
  • lack of coordination,
  • weakness, or
  • unsteadiness.

Serious side effects of Dronabinol include:

  • fainting,
  • fast heart rate or pounding heartbeat,
  • seizure (convulsions),
  • fainting,
  • unusual thoughts or behavior, or
  • mental/mood changes (such as nervousness, hallucinations, abnormal thoughts, extreme fear, or paranoia).

Rare side effects of the Dronabinol include:

  • none 

This is not a complete list of side effects and other serious side effects or health problems that may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

What Other Drugs Interact with Dronabinol?

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Dronabinol has severe interactions with the following drugs:
  • Dronabinol has serious interactions with the following drugs:
  • Dronabinol has moderate interactions with at least 94 other drugs.
  • Dronabinol has minor interactions with no other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

What Are Warnings and Precautions for Dronabinol?


  • Hypersensitivity to dronabinol
  • Capsule: Hypersensitivity to sesame seed oil
  • Oral solution
  • History of hypersensitivity reaction to alcohol
  • Patients who are receiving, or have received, disulfiram- or metronidazole-containing products within the past 14 days

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Dronabinol?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Dronabinol?”


  • Neurologic effects
    • May cause psychiatric and cognitive effects and impair mental and/or physical abilities
    • Monitor patients with mania, depression, or schizophrenia; dronabinol may exacerbate these illnesses
    • Avoid patients with a psychiatric history
    • Monitor for symptoms and avoid concomitant use of drugs with similar effects; reduce the dose or discontinue use if signs or symptoms of cognitive impairment develop
    • Inform patients not to operate motor vehicles or other dangerous machinery until they are reasonably certain that dronabinol does not affect them adversely
    • Abrupt discontinuation may cause withdrawal symptoms
  • Hemodynamic instability
    • Patients with cardiac disorders may experience hypotension, hypertension, syncope, or tachycardia
    • Avoid concomitant use of drugs with similar effects and monitor for hemodynamic changes; monitor patients for changes in blood pressure, heart rate, and syncope after initiating or increasing the dosage
    • Caution when initiating or increasing the dosage
    • Caution in elderly patients; may be more sensitive to neurological, psychoactive, and postural hypotensive effects of drug
  • Seizures
    • Seizures and seizure-like activity reported
    • Weigh potential risks before prescribing to patients with a history of seizures, including those with factors that can lower the seizure threshold
    • If a seizure occurs, discontinue dronabinol immediately
  • Multiple substance abuse
    • Patients with a history of substance abuse or dependence, including marijuana or alcohol, may be more likely to abuse dronabinol
    • Assess risk for abuse or misuse before prescribing
  • Paradoxical Nausea, vomiting, or abdominal pain
    • New or worsening nausea, vomiting, or abdominal pain can occur during treatment with synthetic delta-9 tetrahydrocannabinol (delta-9-THC), the active ingredient in dronabinol
    • In some cases, these adverse reactions were severe (.g, dehydration, electrolyte abnormalities) and required dose reduction or drug discontinuation
    • Symptoms are similar to cannabinoid hyperemesis syndrome (CHS), which is described as cyclical events of abdominal pain, nausea, and vomiting in chronic, long-term users of delta-9-THC products
    • Patients may not recognize these symptoms as abnormal; specifically monitor for the development of worsening nausea, vomiting, or abdominal pain
  • Toxicities related to propylene glycol in preterm neonates
    • Contains the excipients dehydrated alcohol (50%, w/w) and propylene glycol (5.5%, w/w)
    • Large amounts of propylene glycol are potentially toxic and have been associated with seizures, lactic acidosis, respiratory depression, and respiratory depression
    • When administered concomitantly with propylene glycol, ethanol competitively inhibits the metabolism of propylene glycol, which may lead to elevated concentrations of propylene glycol
    • Preterm neonates may be at increased risk of propylene glycol-associated adverse reactions due to a diminished ability to metabolize propylene glycol, thereby, leading to accumulation
    • The safety and effectiveness of dronabinol have not been established in pediatric patients
  • Drug interaction overview
    • Coadministration with disulfiram or metronidazole may cause disulfiram-like reactions (.g, abdominal cramps, nausea, vomiting, headaches, and flushing); discontinue disulfiram or metronidazole at least 14 days before initiating dronabinol and do not administer these products within 7 days of completing treatment with dronabinol
    • Inhibitors and inducers of CYP2C9 and CYP3A4: May alter dronabinol systemic exposure; monitor for dronabinol-related adverse reactions or loss of efficacy
    • Highly protein-bound drugs: Potential for the displacement of other drugs from plasma proteins; monitor for adverse reactions to concomitant narrow therapeutic index drugs (.g, warfarin, cyclosporine, or amphotericin B) when initiating dronabinol or increasing the dosage
    • Caution in patients receiving concomitant therapy with sedatives, hypnotics, or other psychoactive drugs because of the potential for additive or synergistic CNS effects
    • Caution in pregnant patients, nursing mothers, or pediatric patients; not studied

Pregnancy & Lactation

  • May cause fetal harm; avoid use during pregnancy
  • Published studies suggest that during pregnancy, the use of cannabis, which includes THC, whether for recreational or medicinal purposes, may increase the risk of adverse fetal/neonatal outcomes including fetal growth restriction, low birth weight, preterm birth, small-for-gestational-age, admission to the NICU, and stillbirth
  • Contains alcohol; alcohol is associated with fetal harm including central nervous system abnormalities, behavioral disorders, and impaired intellectual development
  • Delta-9-THC has been measured in the cord blood of some infants whose mothers reported prenatal use of cannabis, suggesting that dronabinol may cross the placenta to the fetus during pregnancy
  • Effects of delta-9-THC on the fetus are not known
  • Lactation 
    • Women with HIF: Advice HIV infected women not to breastfeed
    • Women with CINV: Do not breastfeed during treatment with dronabinol and for 9 days after the last dose


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