DrugindexOnline^{2nd edition}

Pronouncation: (NA-bi-lone)
Class: Antiemetic, Antivertigo

Trade Names:
Cesamet
- Capsules 1 mg

Mechanism of Action

Pharmacology

Has complex effects on the CNS; interacts with the cannabinoid receptor system in neural tissue.

Pharmacokinetics

Absorption

Completely absorbed following oral ingestion. C _max occurs within 2 hr.

Distribution

Vd is approximately 12.5 L/kg.

Metabolism

Extensively metabolized; however, information about the metabolites and their activities is not available.

Elimination

Nabilone t _½ is approximately 2 hr. Approximately 60% is excreted in the feces via the biliary system and 24% in urine.

Special Populations

Hepatic and Renal Function Impairment

Effects have not been determined.

Indications and Usage

Treatment of nausea and vomiting associated with cancer chemotherapy in patients who have failed to respond adequately to conventional antiemetic treatments.

Contraindications

Standard considerations.

Dosage and Administration

Adults

PO 1 or 2 mg bid. On the day of chemotherapy, administer the initial dose 1 to 3 hr before giving the chemotherapeutic agent. May be administered during the entire chemotherapy cycle and for 48 hr after the last dose of each chemotherapy cycle. Max dose: 2 mg tid.

General Advice

• Food does not affect absorption of the drug.

Storage/Stability

Store at 59° to 86°F.

Drug Interactions

Anticholinergic agents (eg, atropine, scopolamine), tricyclic antidepressants (eg, amitriptyline)

Additive or potentiation of tachycardia and drowsiness.

Barbiturates

Cl may be decreased by nabilone, increasing the risk of adverse reactions.

CNS depressants (eg, alcohol, barbiturates, benzodiazepines, buspirone, codeine, muscle relaxants)

Additive depressant effects. Psychomotor function is particularly impaired when coadministered with diazepam.

Disulfiram, fluoxetine

Risk of hypomania may be increased.

Highly protein-bound drugs

May be displaced, leading to transient increases in pharmacologic activity.

Naltrexone

Opioid blockade may enhance effects of nabilone.

Opioids

Cross-tolerance and mutual potentiation may occur.

Sympathomimetic agents (eg, amphetamines)

Additive hypertension and tachycardia, possible cardiotoxicity.

Theophylline

Metabolism of theophylline may be increased, reducing the therapeutic effect.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Hypotension (8%); arrhythmia; cerebral vascular accident; flushing; hypertension; orthostatic hypotension; palpitation; syncope; tachycardia.

CNS

Drowsiness (66%); dizziness/vertigo (59%); euphoria (38%); ataxia, depression (14%); difficulty concentrating (12%); sleep disturbance (11%); dysphoria (9%); asthenia (8%); headache (7%); sedation (3%); depersonalization, disorientation (2%); abnormal dreams, abnormal thinking, akathisia, anxiety, apathy, CNS stimulation, circumoral paresthesia, confusion, convulsions, disorientation, disturbed coordination, disturbed perception, dystonia, emotional disorder, emotional lability, fatigue, hallucinations, hyperactivity, inebriated feeling, insomnia, irritability, light-headedness, malaise, mood swings, nervousness, numbness, paranoia, paresthesia, phobic neurosis, somnolence, speech disorder, stupor, taste change, thought disorder, toxic psychosis, tremor, twitching, unconsciousness, withdrawal panic disorder (postmarketing).

Dermatologic

Allergic reactions; anhidrosis; excessive sweating; photosensitivity; pruritus; rash.

EENT

Visual disturbances (13%); amblyopia; dry nose; dry throat; ear tightness; equilibrium dysfunction; eye disorder; eye irritation; eye swelling; eyelid disease; nasal congestion; nosebleed; pharyngitis; photophobia; pupil dilation; tinnitus; visual field defect; voice change.

GI

Dry mouth (36%); anorexia (8%); nausea (4%); abdominal pain; aphthous ulcer; constipation; diarrhea; dyspepsia; gastritis; mouth irritation; thick tongue; vomiting.

Genitourinary

Decreased urination; frequency of micturition; increased urination; urinary retention.

Hematologic-Lymphatic

Anemia, leukopenia (postmarketing).

Metabolic-Nutritional

Thirst.

Musculoskeletal

Back pain; joint pain; muscle pain; neck pain; unspecified pain.

Respiratory

Cough; dyspnea; sinus headache; wheezing.

Miscellaneous

Increased appetite (2%); bacterial infection, chest pain, chills, face edema, fever, inhibited walking (postmarketing).

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Elderly

Use with caution, usually starting at the low end of the dosage range because of the greater frequency of decreased hepatic, renal, or cardiac function, and concomitant diseases or other drug therapy.

Special Risk Patients

Use with caution in patients with hypertension or heart disease.

CNS effects

Adverse psychiatric reactions may persist for 72 hr following cessation of therapy.

Drug dependence

Because of the high abuse potential, limit prescriptions to the amount necessary for a single cycle of chemotherapy (a few days).

Previous psychiatric disorders

Use with caution in patients with history of psychiatric disorders (eg, depression, manic depressive illness, schizophrenia) because symptoms of these disorders may be unmasked.

Overdosage

Symptoms

Anxiety reactions; coma; hypertension; hypotension; orthostatic hypotension; psychotic episodes, including hallucinations; respiratory depression; tachycardia.

Patient Information

• Explain name, dose, action, and potential adverse reactions of drug.
• Obtain patient history, including drug history and any known allergies.
• Caution patient not to drive, operate machinery, or engage in hazardous activities.
• Advise patient of possible changes in mood and other adverse behavioral effects of nabilone.
• Caution patient to remain under supervision of a responsible adult while taking nabilone.
• Alert patient to the potential for additive CNS depression with concurrent use of alcohol or other depressants.
• Advise women to notify health care provider if pregnant, planning to become pregnant, or breast-feeding.
• Caution patient not to take any prescription or OTC medications, herbal preparations, or dietary supplements unless advised by health care provider.
• Advise patient that follow-up visits may be necessary and to keep appointments.