ESTAZOLAM
| ESTAZOLAM (es-ta-zo'lam) Classifications: anxiolytic; sedative-hypnotic; benzodiazepine; Therapeutic: antianxiety; sedative-hypnotic Prototype: Lorazepam Pregnancy Category: X Controlled Substance: Schedule IV |
Availability
1 mg, 2 mg tablets
Action
Benzodiazepine whose effects (anxiolytic, sedative, hypnotic, skeletal muscle relaxant) are mediated by the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). GABA acts at the thalamic, hypothalamic, and limbic levels of CNS.
Therapeutic Effect
Benzodiazepines generally decrease the number of awakenings from sleep. Stage 2 sleep is increased with all benzodiazepines. Estazolam shortens stages 3 and 4 (slow-wave sleep), and REM sleep is shortened. The total sleep time, however, is increased.
Uses
Short-term management of insomnia.
Contraindications
Known sensitivity to benzodiazepines; acute closed-angle glaucoma, primary depressive disorders or psychosis; abrupt discontinuation; children <18 y; coma, shock, acute alcohol intoxication; pregnancy (category X), lactation.
Cautious Use
Renal and hepatic impairment, renal failure; organic brain syndrome, alcoholism, benzodiazepine dependence, suicidal ideations, CNS depression, seizure disorder, status epilepticus; substance abuse; shock, coma; dementia, mania, psychosis; myasthenia gravis, Parkinson's disease; sleep apnea; open-angle glaucoma, GI disorders, older adult and debilitated patients; limited pulmonary reserve, pulmonary disease, COPD.
Route & Dosage
| Insomnia Adult: PO 1 mg h.s. may increase up to 2 mg if necessary (some debilitated older adult patients should start with 0.5 mg h.s.) |
Administration
Oral- For older adult patients in good health, a 1 mg dose is indicated; reduce initial dose to 0.5 mg for debilitated or small older adult patients.
- Dosage reduction also may be needed in the presence of hepatic impairment.
Adverse Effects (≥1%)
CNS: Headache, dizziness, impaired coordination, hypokinesia, somnolence, hangover, weakness. CV: Palpitations, arrhythmias, syncope (all rare). Hematologic: Leukopenia, agranulocytosis. GI: Constipation, xerostomia, anorexia, flatulence, vomiting. Musculoskeletal: Arthritis, arthralgia, myalgia, muscle spasm.Interactions
Drug: Cimetidine may decrease metabolism of estazolam and increase its effects; alcohol and other cns depressants may increase drowsiness; CYP3A4 inhibitors (ketoconazole, itraconazole, nefazodone, diltiazem, fluvoxamine, cimetidine, isoniazid, erythromycin) can increase concentrations and toxicity of estazolam; carbamazepine, phenytoin, rifampin, barbiturates may decrease estazolam concentrations. Food: Grapefruit juice >1 quart may increase toxicity. Herbal: Kava, valerian may potentiate sedation.Pharmacokinetics
Absorption: Rapidly absorbed from GI tract. Onset: 20–30 min. Peak: 2 h. Distribution: Crosses rapidly into brain; crosses placenta; distributed into breast milk. Metabolism: Extensively in liver. Elimination: In urine. Half-Life: 10–24 h.Nursing Implications
Assessment & Drug Effects
- Monitor for improvement in S&S of insomnia.
- Assess for excess CNS depression or daytime sedation.
- Assess for safety, especially with older adult or debilitated patients, as dizziness and impaired coordination are known adverse effects.
Patient & Family Education
- Learn adverse effects and report those experienced to the physician.
- Avoid using this drug in combination with other CNS depressant drugs or alcohol.
- Do not drive or engage in other potentially hazardous activities until response to drug is known.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug