ESTAZOLAM
Clinical safety rating: avoid
Positive evidence of fetus risks but benefits may outweigh risks in some cases
Benzodiazepine that binds to GABA-A receptors at the alpha-1 subunit, enhancing the effect of GABA by increasing chloride ion conductance, leading to neuronal hyperpolarization and CNS depression.
| Metabolism | Primarily hepatic via CYP3A4; active metabolite (hydroxyestazolam) with half-life ~19 hours; excreted renally. |
| Excretion | Renal: ~90% as metabolites, <1% unchanged. Fecal: small amount, ~10%. |
| Half-life | Terminal elimination half-life: 10-24 hours (mean ~17 hours); prolonged in elderly and hepatic impairment. |
| Protein binding | ~93% bound to albumin. |
| Volume of Distribution | 0.8-1.3 L/kg; reflects moderate tissue distribution. |
| Bioavailability | Oral: ~70-90% (extensive first-pass metabolism). |
| Onset of Action | Oral: 30-60 minutes; IV: not applicable. |
| Duration of Action | 6-8 hours; clinical effect may persist longer due to active metabolites. |
1-2 mg orally at bedtime.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for GFR ≥ 30 mL/min. For GFR < 30 mL/min, use with caution and consider dose reduction due to potential accumulation of active metabolites. |
| Liver impairment | Child-Pugh Class A: No adjustment necessary. Child-Pugh Class B: Reduce dose by 50% (e.g., 1 mg maximum). Child-Pugh Class C: Avoid use. |
| Pediatric use | Not recommended for use in pediatric patients under 18 years of age due to lack of safety and efficacy data. |
| Geriatric use | Initial dose: 0.5 mg orally at bedtime, with maximum dose of 1 mg due to increased sensitivity and risk of falls and cognitive impairment. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
CNS depressants including alcohol and opioids increase sedation risk Abrupt discontinuation can cause withdrawal symptoms.
| Breastfeeding | Excreted into breast milk; M/P ratio unknown. Potential for neonatal sedation, poor feeding, and withdrawal. Contraindicated in breastfeeding. |
| Teratogenic Risk | Pregnancy Category X. First trimester: increased risk of congenital malformations, particularly cleft lip/palate. Second and third trimesters: fetal benzodiazepine exposure associated with floppy infant syndrome, neonatal withdrawal (irritability, tremors, hypertonia), and respiratory depression. Use contraindicated in pregnancy. |
■ FDA Black Box Warning
Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required.
| Common Effects | Sedation |
| Serious Effects |
["Hypersensitivity to estazolam or other benzodiazepines.","Narrow-angle glaucoma (if untreated).","Severe respiratory insufficiency (e.g., COPD, sleep apnea).","Myasthenia gravis.","Concurrent use with ketoconazole, itraconazole, or other potent CYP3A4 inhibitors (can increase estazolam levels)."]
| Precautions | ["Risk of dependence and withdrawal reactions; avoid abrupt discontinuation.","CNS depressant effects; caution with other CNS depressants.","Respiratory depression risk, especially in patients with COPD or sleep apnea.","Elderly patients: increased sensitivity and risk of falls.","May cause anterograde amnesia, paranoia, and depression.","Potential for abuse and misuse."] |
Loading safety data…
| Fetal Monitoring |
| Monitor maternal respiratory status, sedation level, and abuse potential. In pregnancy, fetal ultrasound for anomalies and neonatal monitoring for withdrawal signs and respiratory depression if inadvertent exposure occurs. |
| Fertility Effects | No direct evidence of impaired fertility. Chronic use may affect menstrual regularity and libido, potentially impacting fertility. |