SYNDROS (Page 4 of 6)

8.4 Pediatric Use

The safety and effectiveness of SYNDROS have not been established in pediatric patients.

Pediatric patients may be more sensitive to neurological and psychoactive effects of SYNDROS [see Warnings and Precautions ( 5.1)]. SYNDROS contains the excipients 50% (w/w) dehydrated alcohol and 5.5% (w/w) 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 events due to diminished ability to metabolize propylene glycol, thereby, leading to accumulation [see Warnings and Precautions (5.7)].

8.5 Geriatric Use

Clinical studies of dronabinol capsules in AIDS and cancer patients did not include 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 SYNDROS [see Warnings and Precautions (5.1, 5.2)].

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 SYNDROS [see Warnings and Precautions (5.1)]. These patients should be monitored closely and placed on fall precautions prior to initiating SYNDROS 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 (2.2, 2.3)].

8.6 Effect of CYP2C9 Polymorphism

Published data suggest that systemic clearance of dronabinol may be reduced and concentrations may be increased in presence of CYP2C9 genetic polymorphism. Monitoring for increased adverse reactions is recommended in patients known to carry genetic variants associated with diminished CYP2C9 function [see Clinical Pharmacology (12.5)].


9.1 Controlled Substance

SYNDROS contains dronabinol oral solution, a Schedule II controlled substance.

9.2 Abuse

SYNDROS contains dronabinol, the main psychoactive component in marijuana. Ingestion of high doses of dronabinol increases the risk of psychiatric adverse reactions if abused or misused, while continued administration can lead to addiction. Psychiatric adverse reactions may include psychosis, hallucinations, depersonalization, mood alteration, and paranoia.

In vitro studies demonstrate that SYNDROS can be easily and effectively abused without manipulation. SYNDROS contains 50% (w/w) dehydrated alcohol [see Warning and Precautions ( 5.5)].

In a randomized, single-dose, double-blind, placebo- and active-controlled crossover pharmacodynamic study of 43 experienced marijuana smokers, “drug liking” responses and safety of SYNDROS were compared with placebo and dronabinol in sesame oil oral capsules. Treatment arms were 10 mg and 30 mg dronabinol capsules, 10 mg and 30 mg dronabinol from SYNDROS, and placebo oral solution and capsules. Greater “drug liking” scores were reported with the 30 mg dose, compared with the 10 mg dose, for both SYNDROS and dronabinol-containing capsules. Overall, the pharmacodynamic results from this study demonstrated no statistically significant differences in various measures of drug liking for the doses taken, though the SYNDROS results were consistently greater than those of dronabinol capsules. Similarly, observed adverse reactions were greater for SYNDROS. The pharmacodynamic and safety effects of SYNDROS following multiple doses have not been evaluated.

Patients should be instructed to keep SYNDROS in a secure place out of reach of others for whom the medication has not been prescribed.

9.3 Dependence

Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use. Physical dependence manifests by drug class-specific withdrawal symptoms after abrupt discontinuation or a significant dose reduction of a drug. The appearance of a withdrawal syndrome when administration of the drug is terminated is the only actual evidence of physical dependence. Physical dependence can develop during chronic therapy with SYNDROS and develops after chronic abuse of marijuana.

A withdrawal syndrome was reported after the abrupt discontinuation of dronabinol capsules in subjects receiving dosages of 210 mg per day for 12 to 16 consecutive days. Within 12 hours after discontinuation, subjects manifested symptoms such as irritability, insomnia, and restlessness. By approximately 24 hours post-dronabinol discontinuation, withdrawal symptoms intensified to include “hot flashes”, sweating, rhinorrhea, loose stools, hiccoughs, and anorexia. These withdrawal symptoms gradually dissipated over the next 48 hours.

Electroencephalographic changes consistent with the effects of drug withdrawal (hyperexcitation) were recorded in patients after abrupt dechallenge. Patients also complained of disturbed sleep for several weeks after discontinuing therapy with high dosages of dronabinol.


SYNDROS contains 50% (w/w) dehydrated alcohol and 5.5% (w/w) propylene glycol. Ingestion of the product over the recommended dose could result in significant toxicity.


Signs and symptoms of dronabinol overdose include drowsiness, euphoria, heightened sensory awareness, altered time perception, reddened conjunctiva, dry mouth, tachycardia, memory impairment, depersonalization, mood alteration, urinary retention, reduced bowel motility, decreased motor coordination, lethargy, slurred speech, and postural hypotension. Patients may also experience panic reactions if they have a prior history of nervousness or anxiety and seizures may occur in patients with existing seizure disorders.

It is not known if dronabinol can be removed by dialysis in cases of overdose.


Signs and symptoms of alcohol overdose include changes in mood or behavior, impaired judgment or social functioning, and one or more physical signs such as slurred speech, unsteadiness, lack of coordination, increased or irregular heart rate, respiratory depression, impaired attention, or loss of consciousness.

Propylene Glycol

Signs and symptoms of acute poisoning occur only in rare circumstances where patients ingest large amounts of propylene glycol over several days. These include hypoglycemia, severe metabolic acidosis (caused by the metabolism into lactic acid), and CNS depression including coma and seizures.

Management of Overdosage

If over-exposure of SYNDROS occurs, call your Poison Control Center at 1-800-222-1222 for current information on the management of poisoning or overdosage.


Dronabinol is a cannabinoid designated chemically as (6aR,10aR)-6a,7,8,10a-Tetrahydro-6,6,9-trimethyl-3-pentyl-6H-dibenzo[b,d]-pyran-1-ol. Dronabinol has the following empirical and structural formulas:

Dronabinol Structural Formula
(click image for full-size original)

C21 H30 O2 (molecular weight=314.46)

Dronabinol is a clear colorless to amber oil. Dronabinol is insoluble in water. It has a pKa of 10.6 and an octanol-water partition coefficient: 6,000:1 at pH 7.

SYNDROS (dronabinol) oral solution, 5 mg/mL is a clear, pale yellow to brown solution. Each mL of SYNDROS contains 5 mg of dronabinol as an active ingredient and the following inactive ingredients: 50 % (w/w) dehydrated alcohol, polyethylene glycol 400, propylene glycol, sucralose, methyl paraben, propyl paraben, butylated hydroxyanisole, and water.


12.1 Mechanism of Action

Dronabinol is an orally active cannabinoid that has complex effects on the CNS, including central sympathomimetic activity. Cannabinoid receptors have been discovered in neural tissues. These receptors may play a role in mediating the effects of dronabinol.

12.2 Pharmacodynamics

Effects on the Cardiovascular System

Dronabinol-induced sympathomimetic activity may result in tachycardia and/or conjunctival injection. Its effects on blood pressure are inconsistent, but subjects have experienced orthostatic hypotension and/or syncope upon abrupt standing [see Warnings and Precautions (5.2)].

Effects on the Central Nervous System

Dronabinol also demonstrates reversible effects on appetite, mood, cognition, memory, and perception. These phenomena appear to be dose-related, increasing in frequency with higher dosages, and subject to great inter-patient variability. After oral administration, dronabinol capsules have an onset of action of approximately 0.5 to 1 hours and peak effect at 2 to 4 hours. Duration of action for psychoactive effects is 4 to 6 hours, but the appetite stimulant effect of dronabinol may continue for 24 hours or longer after administration.

Tachyphylaxis and tolerance develop to some of the cardiovascular and CNS pharmacologic effects of dronabinol with chronic use, suggesting an indirect effect on sympathetic neurons. In a study of the pharmacodynamics of chronic dronabinol exposure, healthy male subjects (N = 12) received 12 times the maximum dose for anorexia associated with weight loss in patients with AIDS of dronabinol capsules in divided doses for 16 days. An initial tachycardia induced by dronabinol was replaced successively by normal sinus rhythm and then bradycardia. A decrease in supine blood pressure, made worse by standing, was also observed initially. These subjects developed tolerance to the cardiovascular and subjective adverse CNS effects of dronabinol within 12 days of treatment initiation.

Tachyphylaxis and tolerance do not appear to develop to the appetite stimulant effect of dronabinol. In clinical studies of dronabinol capsules in AIDS patients, at the recommended dosage, the appetite stimulant effect was sustained for up to five months.

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