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Medication Safety Issues
Sound-alike/look-alike issues:
Temazepam may be confused with flurazepam, lorazepam
Restoril® may be confused with Vistaril®, Zestril®
Pronunciation
(te MAZ e pam)
U.S. Brand Names
Generic Available
Yes
Canadian Brand Names
Pharmacologic Category
Use
Short-term treatment of insomnia
Use: Unlabeled/Investigational
Treatment of anxiety; adjunct in the treatment of depression; management of panic attacks
Restrictions
C-IV
Pregnancy Risk Factor
X
Lactation
Enters breast milk/not recommended (AAP rates “of concern”)
Contraindications
Hypersensitivity to temazepam or any component of the formulation (cross-sensitivity with other benzodiazepines may exist); narrow-angle glaucoma (not in product labeling, however, benzodiazepines are contraindicated); pregnancy
Warnings/Precautions
Concerns related to adverse effects:
• Anterograde amnesia: Benzodiazepines have been associated with anterograde amnesia.
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).
• Hypersensitivity reactions: Postmarketing studies have indicated that the use of hypnotic/sedative agents for sleep has been associated with hypersensitivity reactions including anaphylaxis as well as angioedema.
• Paradoxical reactions: Paradoxical reactions, including hyperactive or aggressive behavior, have been reported with benzodiazepines, particularly in adolescent/pediatric or psychiatric patients.
• Sleep-related activities: An increased risk for hazardous sleep-related activities such as sleep-driving; cooking and eating food, and making phone calls while asleep have also been noted.
Disease-related concerns:
• Depression: Use caution in patients with depression, particularly if suicidal risk may be present.
• Drug abuse: Use with caution in patients with a history of drug abuse or acute alcoholism; potential for drug dependency exists. Tolerance, psychological and physical dependence may occur with prolonged use.
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Impaired gag reflux: Use with caution in patients with an impaired gag reflux.
• Renal impairment: Use with caution in patients with renal impairment.
• Respiratory disease: Use with caution in patients with respiratory disease.
Concurrent drug therapy issues:
• CNS depressants/psychoactive medications: Use with caution in patients receiving other CNS depressants or psychoactive medication; effects with other sedative drugs or ethanol may be potentiated.
Special populations:
• Debilitated patients: Use with caution in debilitated patients.
• Elderly: Use with caution in the elderly; benzodiazepines have been associated with falls and traumatic injury.
• Fall risk: Use with extreme caution in patients who are at risk of falls; benzodiazepines have been associated with falls and traumatic injury.
Other warnings/precautions:
• Appropriate use: Does not have analgesic, antidepressant, or antipsychotic properties.
• Hypnotic: Appropriate use: Should be used only after evaluation of potential causes of sleep disturbance. Failure of sleep disturbance to resolve after 7-10 days may indicate psychiatric or medical illness. A worsening of insomnia or the emergence of new abnormalities of thought or behavior may represent unrecognized psychiatric or medical illness and requires immediate and careful evaluation.
• Withdrawal: Rebound or withdrawal symptoms may occur following abrupt discontinuation or large decreases in dose. Use caution when reducing dose or withdrawing therapy; decrease slowly and monitor for withdrawal symptoms. Flumazenil may cause withdrawal in patients receiving long-term benzodiazepine therapy.
Adverse Reactions
1% to 10%:
Central nervous system: Confusion, dizziness, drowsiness, fatigue, anxiety, headache, lethargy, hangover, euphoria, vertigo
Dermatologic: Rash
Endocrine & metabolic: Decreased libido
Gastrointestinal: Diarrhea
Neuromuscular & skeletal: Dysarthria, weakness
Ocular: Blurred vision
Miscellaneous: Diaphoresis
<1%: Amnesia, anorexia, ataxia, back pain, blood dyscrasias, drug dependence, increased dreaming, menstrual irregularities, palpitation, paradoxical reactions, reflex slowing, tremor, vomiting
Postmarketing and/or case reports: Anaphylaxis, angioedema, complex sleep-related behavior (sleep-driving, cooking or eating food, making phone calls)
Drug Interactions
Substrate (minor) of CYP2B6, 2C9, 2C19, 3A4
CNS depressants: Sedative effects and/or respiratory depression may be additive with CNS depressants; includes ethanol, barbiturates, opioid analgesics, and other sedative agents; monitor for increased effect
Theophylline: May partially antagonize some of the effects of benzodiazepines; monitor for decreased response; may require higher doses for sedation
Ethanol/Nutrition/Herb Interactions
Ethanol: Avoid ethanol (may increase CNS depression).
Food: Serum levels may be increased by grapefruit juice.
Herb/Nutraceutical: St John's wort may decrease temazepam levels. Avoid valerian, St John's wort, kava kava, gotu kola (may increase CNS depression).
Mechanism of Action
Binds to stereospecific benzodiazepine receptors on the postsynaptic GABA neuron at several sites within the central nervous system, including the limbic system, reticular formation. Enhancement of the inhibitory effect of GABA on neuronal excitability results by increased neuronal membrane permeability to chloride ions. This shift in chloride ions results in hyperpolarization (a less excitable state) and stabilization.
Pharmacodynamics/Kinetics
Distribution: Vd: 1.4 L/kg
Protein binding: 96%
Metabolism: Hepatic
Half-life elimination: 9.5-12.4 hours
Time to peak, serum: 2-3 hours
Excretion: Urine (80% to 90% as inactive metabolites)
Dosage
Oral:
Adults: 15-30 mg at bedtime
Elderly or debilitated patients: 15 mg
Monitoring Parameters
Respiratory and cardiovascular status
Reference Range
Therapeutic: 26 ng/mL after 24 hours
Patient Education
Use exactly as directed; do not increase dose or frequency or discontinue without consulting prescriber. Drug may cause physical and/or psychological dependence. May take with food to decrease GI upset. While using this medication, do not use alcohol or other prescription or OTC medications (especially, pain medications, sedatives, antihistamines, or hypnotics) without consulting prescriber. Maintain adequate hydration (2-3 L/day of fluids) unless instructed to restrict fluid intake. You may experience drowsiness, dizziness, lightheadedness, or blurred vision (use caution when driving or engaging in tasks requiring alertness until response to drug is known); or dry mouth or GI discomfort (small frequent meals, frequent mouth care, chewing gum, or sucking lozenges may help). Report CNS changes (confusion, depression, increased sedation, excitation, headache, abnormal thinking, insomnia, or nightmares, memory impairment, impaired coordination); muscle pain or weakness; respiratory difficulty; unusual swelling, especially on face or neck; persistent dizziness, chest pain, or palpitations; alterations in normal gait; vision changes; or ineffectiveness of medication. Pregnancy/breast-feeding precautions: Inform prescriber if you are pregnant. Do not get pregnant during or for 1 month following therapy. Consult prescriber for instruction on appropriate contraceptive measures. This drug may cause severe fetal defects. Breast-feeding is not recommended.
Geriatric Considerations
Because of its lack of active metabolites, temazepam is recommended in the elderly when a benzodiazepine hypnotic is indicated. Hypnotic use should be limited to 10-14 days. If insomnia persists, the patient should be evaluated for etiology.
Additional Information
Abrupt discontinuation after sustained use (generally >10 days) may cause withdrawal symptoms.
Anesthesia and Critical Care Concerns/Other Considerations
Chronic use of this agent may increase perioperative benzodiazepine dose needed to achieve desired effect. Abrupt discontinuation after sustained use (generally >10 days) may cause withdrawal symptoms. Benzodiazepines, as a class, may depress respiration; may exacerbate sleep-disordered breathing.
Cardiovascular Considerations
Hypotension may result in orthostatic lightheadedness or syncope. Benzodiazepines, as a class, may depress respiration. These medications may often be prescribed for difficulty in sleeping but may exacerbate sleep-disordered breathing.
Dental Health: Effects on Dental Treatment
Key adverse event(s) related to dental treatment: Significant xerostomia (normal salivary flow resumes upon discontinuation).
Dental Health: Vasoconstrictor/Local Anesthetic Precautions
No information available to require special precautions
Mental Health: Comment
There are two subtypes of GABA receptors (GABA-A and GABA-B) and three different benzodiazepine receptors (Bz1, Bz2, and Bz3). Benzodiazepine receptors and effects appear to be linked to the GABA-A receptors. Benzodiazepines do not bind to GABA-B receptors. The role of GABA-B receptors is unclear. Benzodiazepines have no specificity for benzodiazepine receptor subtypes.
Temazepam is a short half-life benzodiazepine. Duration of action after a single dose is determined by redistribution rather than metabolism. Tolerance develops to the sedative, hypnotic, and anticonvulsant effects. It does not develop to the anxiolytic or skeletal muscle relaxing effects. Psychological and physical dependence may occur with prolonged use of benzodiazepines. The onset of withdrawal symptoms is usually seen on the first day without drug and lasts 5-7 days in patients receiving short half-life benzodiazepines, whereas, the onset occurs after 5 days with a duration of 10-14 days after abrupt discontinuance of long half-life benzodiazepines. Risk factors for abuse include alcohol abuse, personality disorders in the patient or the patient's parent(s). Temazepam is slowly absorbed; undergoes phase II metabolism and, therefore, is less likely to be effected in patients with hepatic dysfunction.
Nursing: Physical Assessment/Monitoring
For short-term use. Assess effectiveness and interactions of other medications patient may be taking. Assess for history of addiction (long-term use can result in dependence, abuse, or tolerance) and periodically evaluate need for continued use. Be alert to possibility of anaphylaxis any time during therapy. After long-term use, taper dosage slowly when discontinuing. For inpatient use, institute safety measures and monitor effectiveness and adverse reactions. For outpatients, monitor therapeutic effectiveness and adverse reactions (eg, CNS depression) at beginning of therapy and periodically with long-term use. Assess knowledge/teach patient appropriate use, interventions to reduce side effects, and adverse symptoms to report. Pregnancy risk factor X: Determine that patient is not pregnant before starting therapy. Do not give to sexually-active female patients unless capable of complying with contraceptive use.
Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule: 15 mg, 30 mg
Restoril®: 7.5 mg, 15 mg, 30 mg
Pricing: U.S. (www.drugstore.com)
Capsules (Restoril)
7.5 mg (30): $205.77
15 mg (30): $223.86
30 mg (30): $202.00
Capsules (Temazepam)
15 mg (30): $12.99
30 mg (30): $13.99
References
“American Academy of Pediatrics Committee on Drugs. The Transfer of Drugs and Other Chemicals Into Human Milk,” Pediatrics, 2001, 108(3):776-89.
Divoll M, Greenblatt DJ, Harmatz JS, et al, “Effect of Age and Gender on Disposition of Temazepam,” J Pharm Sci, 1981, 70(10):1104-7.
Grahame-Smith DG, “Misuse of Temazepam,” Br Med J (Clin Res Ed), 1991, 302(6786):1210.
Ho PC, Triggs EJ, Heazlewood V, et al, “Determination of Nitrazepam and Temazepam in Plasma by High Performance Liquid Chromatography,” Ther Drug Monit, 1983, 5(3):303-7.
Klotz U and Kanto J, “Pharmacokinetics and Clinical Use of Flumazenil (Ro 15-1788),” Clin Pharmacokinet, 1988, 14(1):1-12.
Mokhlesi B, Leikin JB, Murray P, et al, “Adult Toxicology in Critical Care: Part II: Specific Poisonings,” Chest, 2003, 123(3):897-922.
Scharf MB, Berkowitz DV, and Brannen DE, “Effectiveness of Low-Dose Temazepam on Sleep Patterns in Geriatric Insomniac Subjects,” Consult Pharm, 1993, 8(12):1367-73.
International Brand Names
Lexi-Comp.com
Last full review/revision May 2008
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