Included as part of the "PRECAUTIONS" Section
Neuropsychiatric Adverse Reactions
Psychiatric Adverse Reactions
Dronabinol has been reported to exacerbate mania, depression, or schizophrenia. Significant CNS symptoms followed oral doses of 0.4 mg/kg (28 mg per 70 kg patient) of MARINOL in antiemetic studies.
Prior to initiating treatment with MARINOL, screen patients for a history of these illnesses. Avoid use in patients with a psychiatric history or, if the drug cannot be avoided, monitor patients for new or worsening psychiatric symptoms during treatment. Also, avoid concomitant use with other drugs that are associated with similar psychiatric effects.
Cognitive Adverse Reactions
Use of MARINOL has been associated with cognitive impairment and altered mental state. Reduce the dose of MARINOL or discontinue use of MARINOL if signs or symptoms of cognitive impairment develop. Elderly patients may be more sensitive to the neurological and psychoactive effects of MARINOL [see Use In Specific Populations].
MARINOL can cause and may impair the mental and/or physical abilities required for the performance of hazardous tasks such as driving a motor vehicle or operating machinery. Concomitant use of other drugs that cause dizziness, confusion, sedation, or somnolence such as CNS depressants may increase this effect (e.g., barbiturates, benzodiazepines, ethanol, lithium, opioids, buspirone, scopolamine, antihistamines, tricyclic antidepressants, other anticholinergic agents, muscle relaxants). Inform patients not to operate motor vehicles or other dangerous machinery until they are reasonably certain that MARINOL does not affect them adversely.
Patients may experience occasional hypotension, possible hypertension, syncope, or tachycardia while taking MARINOL [see CLINICAL PHARMACOLOGY]. Patients with cardiac disorders may be at higher risk. Avoid concomitant use of other drugs that are also associated with similar cardiac effects (e.g., amphetamines, other sympathomimetic agents, atropine, amoxapine, scopolamine, antihistamines, other anticholinergic agents, amitriptyline, desipramine, other tricyclic antidepressants). Monitor patients for changes in blood pressure, heart rate, and syncope after initiating or increasing the dosage of MARINOL.
Seizure and seizure-like activity have been reported in patients receiving dronabinol.
Weigh this potential risk against the benefits before prescribing MARINOL to patients with a history of seizures, including those receiving anti-epileptic medication or with other factors that can lower the seizure threshold. Monitor patients with a history of seizure disorders for worsened seizure control during MARINOL therapy.
If a seizure occurs, advise patients to discontinue MARINOL and contact a healthcare provider immediately.
Multiple Substance Abuse
Patients with a history of substance abuse or dependence, including marijuana or alcohol, may be more likely to abuse MARINOL as well.
Assess each patient’s risk for abuse or misuse prior to prescribing MARINOL and monitor patients with a history of substance abuse during treatment with MARINOL for the development of these behaviors or conditions.
Paradoxical Nausea, Vomiting, Or Abdominal Pain
Nausea, vomiting, or abdominal pain can occur during treatment with synthetic delta-9tetrahydrocannabinol (delta-9-THC), the active ingredient in MARINOL. In some cases, these adverse reactions were severe (e.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.
Because patients may not recognize these symptoms as abnormal, it is important to specifically ask patients or their caregivers about the development of worsening of nausea, vomiting, or abdominal pain while being treated with MARINOL. Consider dose reduction or discontinuing MARINOL if a patient develops worsening nausea, vomiting, or abdominal pain while on treatment.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
Neuropsychiatric Adverse Reactions [see WARNINGS AND PRECAUTIONS]
- Advise patients that psychiatric adverse reactions may occur, especially in patients with a past psychiatric history or in those receiving other drugs also associated with psychiatric effects, and to report to their healthcare provider any new or worsening psychiatric symptoms.
- Advise patients, especially elderly patients, that cognitive impairment or an altered mental state may also occur during treatment with MARINOL and to report to their healthcare provider if they develop signs or symptoms of cognitive impairment.
- Advise patients not to operate motor vehicles or other dangerous machinery until they are reasonably certain that MARINOL does not affect them adversely. Alert patients to the potential for additive central nervous system depression if MARINOL is used concomitantly with alcohol or other CNS depressants such as benzodiazepines and barbiturates.
Advise patients, especially those with cardiac disorders, to report to their healthcare provider if they experience any signs or symptoms of hemodynamic instability, including hypotension, hypertension, syncope or tachycardia, especially after initiating or increasing the dosage of MARINOL [see WARNINGS AND PRECAUTIONS].
Advise patients to discontinue MARINOL and contact a healthcare provider immediately if they experience a seizure [see WARNINGS AND PRECAUTIONS].
Multiple Substance Abuse
Inform patients with a history of substance abuse or dependence, including marijuana or alcohol, that they may be more likely to abuse MARINOL. Advise patients to report to their healthcare provider if they develop abuse behaviors or conditions [see WARNINGS AND PRECAUTIONS].
Paradoxical Nausea, Vomiting, Or Abdominal Pain
Advise patients to report worsening nausea, vomiting or abdominal pain to their healthcare provider [see WARNINGS AND PRECAUTIONS].
Advise pregnant women of the potential risk to a fetus and to avoid use of MARINOL during pregnancy [see Use In Specific Populations].
- Advise HIV infected women with anorexia associated with weight loss, not to breastfeed.
- Advise women with nausea and vomiting associated with cancer chemotherapy not to breastfeed during treatment with MARINOL and for 9 days after the last dose [see Use In Specific Populations].
Carcinogenesis, Mutagenesis, Impairment Of Fertility
In 2-year carcinogenicity studies, there was no evidence of carcinogenicity in rats at doses up to 50 mg/kg/day dronabinol (approximately 20 times the MRHD in AIDS patients on a body surface area basis) or in mice at doses up to 500 mg/kg/day (approximately 100 times the MRHD in AIDS patients on a body surface area basis).
Dronabinol was not genotoxic in the Ames tests, the in vitro chromosomal aberration test in Chinese hamster ovary cells, and the in vivo mouse micronucleus test. However, dronabinol produced a weak positive response in a sister chromatid exchange test in Chinese hamster ovary cells.
In a long-term study (77 days) in rats, oral administration of dronabinol at doses of 30 to 150 mg/m2, equivalent to 2 to 10 times the MRHD of 15 mg/m2/day in AIDS patients or 0.3 to 1.5 times the MRHD of 90 mg/m2/day in cancer patients, reduced ventral prostate, seminal vesicle and epididymal weights and caused a decrease in seminal fluid volume. Decreases in spermatogenesis, number of developing germ cells, and number of Leydig cells in the testis were also observed. However, sperm count, mating success, and testosterone levels were not affected. The significance of these animal findings in humans is not known.
Use In Specific Populations
MARINOL, a synthetic cannabinoid, may cause fetal harm. Avoid use of MARINOL in pregnant women. Although there is little published data on the use of synthetic cannabinoids during pregnancy, use of cannabis (e.g., marijuana) during pregnancy has been associated with adverse fetal/neonatal outcomes [see Clinical Considerations]. Cannabinoids have been found in the umbilical cord blood from pregnant women who smoke cannabis. In animal reproduction studies, no teratogenicity was reported in mice administered dronabinol at up to 30 times the MRHD (maximum recommended human dose) and up to 5 times the MRHD for patients with AIDS and cancer, respectively. Similar findings were reported in pregnant rats administered dronabinol at up to 5 to 20 times the MRHD and 3 times the MRHD for patients with AIDS and cancer, respectively. Decreased maternal weight gain and number of viable pups and increased fetal mortality and early resorptions were observed in both species at doses which induced maternal toxicity. In published studies, offspring of pregnant rats administered delta-9-THC during and after organogenesis have been reported to exhibit neurotoxicity with adverse effects on brain development, including abnormal neuronal connectivity and impairments in cognitive and motor function [see Data].
The estimated background risk of major birth defects and miscarriage for the indicated populations are unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
Fetal/Neonatal Adverse Reactions
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. Therefore, use of cannabis during pregnancy should be avoided.
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. The effects of delta-9-THC on the fetus are not known.
Reproduction studies with dronabinol have been performed in mice at 15 to 450 mg/m2, equivalent to 1 to 30 times the MRHD of 15 mg/m2/day in AIDS patients or 0.2 to 5 times the MRHD of 90 mg/m2/day in cancer patients, and in rats at 74 to 295 mg/m2 (equivalent to 5 to 20 times the MRHD of 15 mg/m2/day in AIDS patients or 0.8 to 3 times the MRHD of 90 mg/m2/day in cancer patients). These studies have revealed no evidence of teratogenicity due to dronabinol. At these dosages in mice and rats, dronabinol decreased maternal weight gain and number of viable pups and increased fetal mortality and early resorptions. Such effects were dose dependent and less apparent at lower doses that produced less maternal toxicity.
Review of published literature indicates that the endocannabinoid system plays a role in neurodevelopmental processes such as neurogenesis, migration, and synaptogenesis. Exposure of pregnant rats to delta-9-THC (during and after organogenesis) may modulate these processes to result in abnormal patterns of neuronal connectivity and subsequent cognitive impairments in the offspring. Nonclinical toxicity studies in pregnant rats and newborn pups have shown prenatal exposure to THC that resulted in impairment of motor function, alteration in synaptic activity, and interference in cortical projection of neuron development in the offspring. Prenatal exposure has shown effects on cognitive function such as learning, short-and long-term memory, attention, decreased ability to remember task, and ability to discriminate between novel and same objects. Overall, prenatal exposure to THC has resulted in significant and long-term changes in brain development, cognition, and behavior in rat offspring.
For mothers infected with the Human Immunodeficiency Virus (HIV), the Centers for Disease Control and Prevention recommends that HIV-infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV. Because of the potential for HIV transmission (in HIV-negative infants) and serious adverse reactions in a breastfed infant, instruct mothers not to breastfeed if they are receiving MARINOL.
For mothers with nausea and vomiting associated with cancer chemotherapy, there are limited data on the presence of dronabinol in human milk, the effects on the breastfed infant, or the effects on milk production. The reported effects of inhaled cannabis transferred to the breastfeeding infant have been inconsistent and insufficient to establish causality. Because of the possible adverse effects from MARINOL on the breastfeeding infant, advise women with nausea and vomiting associated with cancer chemotherapy not to breastfeed during treatment with MARINOL and for 9 days after the last dose.
The safety and effectiveness of MARINOL have not been established in pediatric patients.
Pediatric patients may be more sensitive to neurological and psychoactive effects of MARINOL [see WARNINGS AND PRECAUTIONS].
Clinical studies of MARINOL in AIDS and cancer patients did not include the sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
Elderly patients may be more sensitive to the neuropsychiatric and postural hypotensive effects of MARINOL [see WARNINGS AND PRECAUTIONS].
Elderly patients with dementia are at increased risk for falls as a result of their underlying disease state, which may be exacerbated by the CNS effects of somnolence and dizziness associated with MARINOL [see WARNINGS AND PRECAUTIONS]. These patients should be monitored closely and placed on fall precautions prior to initiating MARINOL therapy. In antiemetic studies, no difference in efficacy was apparent in patients greater than 55 years of age compared to younger patients.
In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of falls, decreased hepatic, renal, or cardiac function, increased sensitivity to psychoactive effects, and of concomitant disease or other drug therapy [see DOSAGE AND ADMINISTRATION].
Effect Of CYP2C9 Polymorphism
Published data suggest that systemic clearance of dronabinol may be reduced and concentrations may be increased in the presence of CYP2C9 genetic polymorphism. Monitoring for potentially increased adverse reactions is recommended in patients known to carry genetic variants associated with diminished CYP2C9 function [see CLINICAL PHARMACOLOGY].