Action And Clinical Pharmacology: Dronabinol, also known as delta-9-tetrahydrocannabinol has been shown to have psychotropic and antiemetic activity. Dronabinol can produce changes in mood, decrease in cognitive performance and memory, decrease in ability to control drives and impulses, and altered perception of reality, particularly altered time sense.
Pharmacokinetics: Dronabinol is readily absorbed from the gastrointestinal tract. The systemic availability, following oral administration, is 10 to 20% relative to an i.v. dose indicating extensive first pass metabolism. Maximum plasma concentrations appear approximately 2 to 3 hours after oral dosing. Dronabinol has a long half-life (approximately 60 hours) due to sequestration in body tissues and to enterohepatic recirculation.
Dronabinol is metabolized chiefly in the liver where it is converted to 11-hydroxy-Dtetrahydrocannabinol and more than 20 other metabolites. The 11-hydroxy-metabolite is psychoactive and appears in the plasma in roughly the same quantities as the parent drug. It has a terminal half-life of approximately 15 to 18 hours.
Biliary excretion is the major route of elimination. Within 72 hours following oral administration, approximately 50% of the dose is recovered in the feces; another 10 to 15% appears in the urine either unchanged or as a metabolite.
Indications And Clinical Uses: In the treatment of severe nausea and vomiting associated with cancer chemotherapy.
Dronabinol is a psychotropic agent which may produce physical and psychological dependence and has the potential to be abused. Dronabinol is scheduled as a narcotic and as such cannot be used or prescribed except for its recognized indication; namely severe nausea and vomiting associated with cancer chemotherapy.
Prescription of dronabinol should be limited to the amount necessary for a single course of antinauseant therapy (i.e. a few days).
Contra-Indications: Dronabinol should not be given to patients sensitive to marijuana, other cannabinoids or sesame oil. Dronabinol should not be given to patients with a history of psychotic disorders or those judged to be intolerant of the drug. tag_WarningWarnings
Manufacturers’ Warnings In Clinical States: Dronabinol can produce physical and psychological dependence and has the potential for being abused. Dronabinol has complex effects on the CNS. These can result in changes of mood, decrease in cognitive performance and memory, decrease in ability to control drives and impulses, and alteration of the perception of reality. Because of its potential to alter the mental state, dronabinol should be used only as indicated and under circumstances that permit close medical supervision of the patient.
Drug administration should be discontinued in patients experiencing a psychotic reaction and the patient should be closely observed in an appropriate setting until his/her mental state returns to normal.
Occupational Hazards: Patients should be warned not to drive or engage in activities requiring unimpaired judgment and coordination.
Pregnancy and Lactation: The safe use of dronabinol during pregnancy has not been established.
There is evidence that dronabinol is excreted in human breast milk and may be absorbed by the nursing baby. Because the effects on the infant of chronic exposure to dronabinol and its metabolites are unknown, nursing mothers should not use it.
Precautions: Dronabinol may cause an increase in sympathomimetic activity. It should be administered with caution to patients with cardiovascular problems, such as tachyarrhythmias, angina pectoris or hypertension.
Dronabinol should not be used in manic depressive or schizophrenic patients as symptoms may be unmasked by cannabinoids. Use dronabinol with caution, if at all, in patients receiving other psychoactive drugs.
Information for the Patient: Patients should be alerted to the additive effects of dronabinol and barbiturates. They should be warned not to drive or engage in activities requiring unimpaired judgment and coordination until the effects of dronabinol have completely subsided.
Adverse Reactions: During controlled clinical trials, the most commonly encountered events were drowsiness, dizziness and transient impairment of sensory and perceptual functions. Psychotropic effects can be observed in most patients. Easy laughing, elation and heightened awareness, often termed a “high”, was described in 24% of dronabinol patients in the reported clinical trials.
In addition to the events enumerated above, the following have been reported at a frequency below 1%: CNS: tinnitus, nightmares. Autonomic Nervous System: speech difficulty, facial flushing, perspiring.
Cardiovascular: syncope. Gastrointestinal: diarrhea, fecal incontinence.
Musculoskeletal: muscular pains.
Symptoms And Treatment Of Overdose: Symptoms and Treatment: Signs and symptoms of overdosage are an extension of the psychotomimetic and physiologic effects of dronabinol.
Overdosage may be considered to have occurred at prescribed dosage if disturbing psychiatric symptoms have occurred. In such case, the patient should be closely observed in a quiet environment and supportive measures, including reassurance, should be used.
Dosage And Administration: The bioavailability of dronabinol by the oral route is variable.
Initial Dose: 5 mg/mgiven 1 to 3 hours prior to administration of chemotherapy.
Repeat Dose: 5 mg/mevery 2 to 4 hours following chemotherapy, when necessary, for a total of not more than 4 to 6 doses/day usually for 1 or 2 days.
Should 5 mg/mprove ineffective and in the absence of significant side effects, the dose may be increased by 2.5 mg/mincrements to a maximum of 10 mg/mper dose. Caution should be exercised since the incidence and severity of disturbing psychiatric adverse reactions increase significantly at these doses.
Availability And Storage: 2.5 mg: Each white, soft gelatin capsule, identified RL, contains: dronabinol 2.5 mg. Nonmedicinal ingredients: gelatin, glycerin, methylparaben, propylparaben, sesame oil, titanium dioxide and purified water. Bottles of 25.
5 mg: Each brown, soft gelatin capsule, identified RL, contains: dronabinol 5 mg. Nonmedicinal ingredients: gelatin, glycerin, methylparaben, propylparaben, sesame oil, titanium dioxide and purified water. Bottles of 25.
10 mg: Each orange, soft gelatin capsule, identified RL, contains: dronabinol 10 mg. Nonmedicinal ingredients: gelatin, glycerin, methylparaben, propylparaben, sesame oil, titanium dioxide and purified water. Bottles of 25.
Store in a cool place, in well sealed amber containers.
MARINOL® Sanofi Dronabinol Antiemetic