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Pronunciation
(droe NAB i nol)
Generic Available (U.S.)
Yes
Index Terms
Controlled Substance
C-III
Brand Names: Canada
Pharmacologic Category
Use: Labeled Indications
Chemotherapy-associated nausea and vomiting refractory to other antiemetic(s); AIDS-related anorexia
Use: Unlabeled/Investigational
Cancer-related anorexia
Pregnancy Risk Factor
C
Pregnancy Considerations
Adverse events have been observed in animal reproduction studies.
Lactation
Enters breast milk/not recommended
Contraindications
Hypersensitivity to dronabinol, cannabinoids, sesame oil, or any component of the formulation, or marijuana; should be avoided in patients with a history of schizophrenia
Warnings/Precautions
Concerns related to adverse effects:
• CNS depression: May impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).
Disease-related concerns:
• Drug abuse: Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists (drug is psychoactive substance in marijuana). Tolerance, psychological and physical dependence may occur with prolonged use.
• Hepatic impairment: Use with caution in patients with hepatic impairment; reduce dosage with severe impairment.
• Psychiatric disorders: Use with caution in patients with mania, depression, or schizophrenia; careful psychiatric monitoring is recommended.
• Seizure disorder: Use with caution in patients with a history of seizure disorder; may lower seizure threshold.
Concurrent drug therapy issues:
• CNS depressants: Effects may be potentiated when used with other psychoactive drugs, sedatives and/or ethanol.
Special populations:
• Elderly: Use with caution in the elderly; may cause postural hypotension.
Other warnings/precautions:
• Withdrawal: May cause withdrawal symptoms upon abrupt discontinuation.
Adverse Reactions
Frequency not always specified.
>1%:
Cardiovascular: Palpitations, tachycardia, vasodilation/facial flushing
Central nervous system: Euphoria (8% to 24%, dose related), abnormal thinking (3% to 10%), dizziness (3% to 10%), paranoia (3% to 10%), somnolence (3% to 10%), amnesia, anxiety, ataxia, confusion, depersonalization, hallucination
Gastrointestinal: Abdominal pain (3% to 10%), nausea (3% to 10%), vomiting (3% to 10%)
Neuromuscular & skeletal: Weakness
<1%, postmarketing, and/or case reports: Conjunctivitis, depression, diarrhea, fatigue, fecal incontinence, flushing, hypotension, myalgia, nightmares, seizure, speech difficulties, tinnitus, vision difficulties
Metabolism/Transport Effects
None known.
Drug Interactions
Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Risk C: Monitor therapy
Anticholinergic Agents: May enhance the tachycardic effect of Cannabinoids. Risk C: Monitor therapy
CNS Depressants: May enhance the adverse/toxic effect of other CNS Depressants. Exceptions: Levocabastine (Nasal). Risk C: Monitor therapy
Cocaine: May enhance the tachycardic effect of Cannabinoids. Risk C: Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (e.g., opioids, barbiturates) with concomitant use. Risk D: Consider therapy modification
HydrOXYzine: May enhance the CNS depressant effect of CNS Depressants. Risk C: Monitor therapy
MAO Inhibitors: May enhance the orthostatic hypotensive effect of Orthostatic Hypotension Producing Agents. Risk C: Monitor therapy
Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Risk D: Consider therapy modification
Ritonavir: May increase the serum concentration of Dronabinol. Risk C: Monitor therapy
Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Risk C: Monitor therapy
Sympathomimetics: Cannabinoids may enhance the tachycardic effect of Sympathomimetics. Risk C: Monitor therapy
Ethanol/Nutrition/Herb Interactions
Ethanol: May increase CNS depression; monitor for increased effects with coadministration. Caution patients about effects.
Food: Administration with high-lipid meals may increase absorption.
Herb/Nutraceutical: St John's wort may decrease dronabinol levels.
Storage
Store under refrigeration (or in a cool environment) between 8°C and 15°C (46°F and 59°F); protect from freezing.
Mechanism of Action
Unknown, may inhibit endorphins in the brain's emetic center, suppress prostaglandin synthesis, and/or inhibit medullary activity through an unspecified cortical action. Some pharmacologic effects appear to involve sympathimometic activity; tachyphylaxis to some effect (eg, tachycardia) may occur, but appetite-stimulating effects do not appear to wane over time. Antiemetic activity may be due to effect on cannabinoid receptors (CB1) within the central nervous system.
Pharmacodynamics/Kinetics
Onset of action: Within 1 hour
Peak effect: 2-4 hours
Duration: 24 hours (appetite stimulation)
Absorption: Oral: 90% to 95%; 10% to 20% of dose gets into systemic circulation
Distribution: Vd: 10 L/kg; dronabinol is highly lipophilic and distributes to adipose tissue
Protein binding: 97% to 99%
Metabolism: Hepatic to at least 50 metabolites, some of which are active; 11-hydroxy-delta-9-tetrahydrocannabinol (11-OH-THC) is the major metabolite; extensive first-pass effect
Half-life elimination: Dronabinol: 25-36 hours (terminal); Dronabinol metabolites: 44-59 hours
Time to peak, serum: 0.5-4 hours
Excretion: Feces (50% as unconjugated metabolites, 5% as unchanged drug); urine (10% to 15% as acid metabolites and conjugates)
Dosage
Refer to individual protocols. Oral:
Antiemetic: Children and Adults: 5 mg/m2 1-3 hours before chemotherapy, then 5 mg/m2/dose every 2-4 hours after chemotherapy for a total of 4-6 doses/day; increase doses in increments of 2.5 mg/m2 to a maximum of 15 mg/m2/dose.
Appetite stimulant: Adults: Initial: 2.5 mg twice daily (before lunch and dinner); titrate up to a maximum of 20 mg/day.
Monitoring Parameters
CNS effects, heart rate, blood pressure, behavioral profile
Reference Range
Antinauseant effects: 5-10 ng/mL
Test Interactions
Decreased FSH, LH, growth hormone, and testosterone
Dietary Considerations
Capsules contain sesame oil.
Patient Education
Avoid alcohol. May cause psychotic reaction, impaired coordination or judgment, faintness, dizziness, drowsiness, clumsiness, unsteadiness, or muscular weakness. Report excessive or persistent CNS changes (euphoria, anxiety, depression, memory lapse, bizarre thought patterns, excitability, inability to control thoughts or behavior, fainting), respiratory difficulties, and rapid heartbeat.
Geriatric Considerations
Elderly patients may be more sensitive to the CNS effects and postural hypotensive effects of dronabinol. Titrate the dose slowly and monitor for adverse effects.
Dental Health: Effects on Dental Treatment
Key adverse event(s) related to dental treatment: Xerostomia (normal salivary flow resumes upon discontinuation) and orthostatic hypotension
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Effects on Mental Status
Drowsiness, anxiety, confusion, and mood changes are common; may cause depression or hallucinations
Mental Health: Effects on Psychiatric Treatment
Concurrent use with barbiturates and benzodiazepines produce additive sedation
Nursing: Physical Assessment/Monitoring
Use caution in the presence of heart disease, hepatic disease, or seizure disorders. Monitor closely for adverse psychotic reactions; this drug is the psychoactive substance in marijuana.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, soft gelatin, oral: 2.5 mg [contains sesame oil], 5 mg [contains sesame oil], 10 mg [contains sesame oil]
Pricing: U.S. (www.drugstore.com)
Capsules (Dronabinol)
2.5 mg (60): $259.99
5 mg (60): $679.93
10 mg (60): $959.89
References
Anderson PO and Muire GG, “Delta-9-Tetrahydrocannabinol as an Antiemetic,” Am J Hosp Pharm, 1981, 38:639-46.
Cat LK and Coleman RL, “Treatment for HIV Wasting Syndrome,” Ann Pharmacother, 1994, 28(5):595-7.
Plasse TF, Gorter RW, Krasnow SH, et al, "Recent Clinical Experience with Dronabinol," Pharmacol Biochem Behav, 1991, 40(3):695-700.
Struwe M, Kaempfer SH, Geiger CJ, et al, “Effect of Dronabinol on Nutritional Status in HIV Infection,” Ann Pharmacother, 1993, 27(7-8):827-31.
Tramer MR, Carroll D, Campbell FA, et al, “Cannabinoids for Control of Chemotherapy Induced Nausea and Vomiting: Quantitative Systematic Review,” BMJ, 2001, 323(7303):16-21.
Voth EA and Schwartz RH, “Medicinal Applications of Delta-9-Tetrahydrocannabinol and Marijuana,” Ann Intern Med, 1979, 126(10):791-8.
International Brand Names
Lexi-Comp.com
Last full review/revision November 2011
Content last modified November 2011
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