temazepam
Restoril

Pharmacologic classification: benzodiazepine
Therapeutic classification: sedative-hypnotic
Pregnancy risk category X
Controlled substance schedule IV

Available forms
Available by prescription only
Capsules: 7.5 mg, 15 mg, 30 mg

Indications and dosages
 Insomnia. Adults: 7.5 to 30 mg P.O. 30 minutes before bedtime.
Elderly patients: Initiate at 7.5 mg P.O. h.s. until individual response is determined.
≡ Dosage adjustment. For debilitated patients, 7.5 mg P.O. h.s. until individual response is determined.

Pharmacodynamics
Sedative-hypnotic action: Temazepam depresses the CNS at the limbic and subcortical levels of the brain. It produces a sedative-hypnotic effect by potentiating the effect of the neurotransmitter gamma-aminobutyric acid on its receptor in the ascending reticular activating system, which increases inhibition and blocks both cortical and limbic arousal.

Pharmacokinetics
Absorption: Well absorbed through the GI tract when administered orally.
Distribution: Widely distributed throughout the body. Drug is 96% protein-bound.
Metabolism: Metabolized in the liver primarily to inactive metabolites.
Excretion: Metabolites are excreted in urine as glucuronide conjugates. Half-life of drug is 10 to 20 hours.

Route Onset Peak Duration
P.O. 1/2-1 hr 1 1/4-1 1/2 hr Unknown


Contraindications and precautions
Contraindicated in pregnant women and in patients hypersensitive to drug or other benzodiazepines.
  Use cautiously in patients with impaired renal or hepatic function, chronic pulmonary insufficiency, severe or latent mental depression, suicidal tendencies, or a history of drug abuse.

Interactions
Drug-drug. Antidepressants, antihistamines, barbiturates, general anesthetics, MAO inhibitors, narcotics, phenothiazines: Enhances CNS depressant effects. Use together cautiously.
Haloperidol: Increases haloperidol levels. Monitor patient closely.
Levodopa: Reduces levodopa therapeutic effect. Use together cautiously.
Drug-herb. Catnip, kava, lady’s slipper, lemon balm, passion flower, sassafras, skullcap, valerian: May increase sedative effects. Discourage use together.
Drug-lifestyle. Alcohol use: Increases CNS depression. Discourage alcohol use.
Smoking: Accelerates temazepam metabolism, which lowers effectiveness. Discourage smoking.

Adverse reactions
CNS: drowsiness, dizziness, lethargy, disturbed coordination, daytime sedation, confusion, nightmares, vertigo, euphoria, weakness, headache, fatigue, nervousness, anxiety, depression, minor changes in EEG patterns.
EENT: blurred vision.
GI: diarrhea, nausea, dry mouth.
Other: physical and psychological dependence.

Effects on lab test results
• May increase AST, ALT, LDH, alkaline phosphatase, and bilirubin levels.

Overdose and treatment
Signs and symptoms of overdose include somnolence, confusion, hypoactive or absent reflexes, dyspnea, labored breathing, hypotension, bradycardia, slurred speech, unsteady gait or impaired coordination, and, ultimately, coma.
 Support blood pressure and respiration until drug effects subside; monitor vital signs. Mechanical ventilatory assistance via endotracheal tube may be required to maintain a patent airway and support adequate oxygenation. Flumazenil, a specific benzodiazepine antagonist, may be useful. Use I.V. fluids and vasopressors, such as dopamine and phenylephrine, to treat hypotension as needed. If patient is conscious, induce emesis. Use gastric lavage if ingestion was recent, but only if an endotracheal tube is present to prevent aspiration. After emesis or lavage, administer activated charcoal with a cathartic as a single dose. Don’t use barbiturates if excitation occurs. Dialysis is of limited value.

Special considerations
• Prolonged use isn’t recommended; however, drug has proved effective for up to 4 weeks of continuous use.
• After long-term use, avoid abrupt withdrawal and follow a gradual tapering dose schedule.
• Drug is useful for patients who have difficulty falling asleep or who awaken frequently in the night.
• Monitor hepatic function studies to prevent toxicity; lower doses are indicated in patients with hepatic dysfunction.
Pregnant patients
• Use is contraindicated during pregnancy because of risk of harm to fetus.
Breast-feeding patients
• Drug appears in breast milk. A breast-fed infant may become sedated, have feeding difficulties, or lose weight. Avoid use in breast-feeding women.
Pediatric patients
• Safe use in patients younger than age 18 hasn’t been established.
Geriatric patients
• These patients are more susceptible to drug’s CNS depressant effects. Use cautiously.

Patient education
• Instruct patient to seek medical approval before changing regimen.
• Inform patient of the risk of physical and psychological dependence with long-term use.
• Caution women about risks to fetus.
• Warn patient about risk of CNS depression with alcohol use and decreased therapeutic benefits related to heavy smoking.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use