ESZOPICLONE

Clinical safety rating: safe

Animal studies have demonstrated safety

How it works

Non-benzodiazepine sedative-hypnotic that binds to GABA-A receptors at a site distinct from benzodiazepine binding site, enhancing GABAergic inhibition and increasing chloride ion conductance.

What the body does with it

Metabolism	Primarily hepatic via CYP3A4 and CYP2E1; metabolites include N-oxide (active) and N-desmethyl (inactive).
Excretion	Renal: 75% (as metabolites, primarily N-desmethyleszopiclone and eszopiclone-N-oxide); Fecal: approximately 10%; less than 10% excreted unchanged in urine.
Half-life	6 hours (range 5-8 hours); at steady state in elderly or hepatic impairment, half-life may be prolonged to approximately 9 hours.
Protein binding	52-59% bound to plasma proteins (primarily albumin).
Volume of Distribution	1.1 L/kg (suggesting extravascular distribution and tissue binding).
Bioavailability	Oral: approximately 80% (due to first-pass metabolism, absolute bioavailability is 50-80% depending on formulation).
Onset of Action	Oral: 30 minutes (peak plasma concentration at 1 hour).
Duration of Action	Approximately 6-8 hours based on sleep maintenance effects; sedation may persist longer in some patients.

Classification & Brands

Dosing & administration

1 mg, 2 mg, or 3 mg orally once daily immediately before bedtime; maximum dose 3 mg/day.

Dosage form	TABLET
Renal impairment	No specific dosage adjustment required for mild to moderate renal impairment. For severe renal impairment (CrCl < 30 mL/min), initial dose should be 1 mg and use with caution.
Liver impairment	In Child-Pugh Class A or B, initial dose 1 mg; maximum dose 2 mg. Contraindicated in Child-Pugh Class C.
Pediatric use	Not approved for use in pediatric patients (safety and efficacy not established).
Geriatric use	Initial dose 1 mg orally once daily immediately before bedtime; maximum dose 2 mg/day due to increased sensitivity and risk of falls.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

CNS depressants including alcohol increase sedation risk May cause complex sleep behaviors like sleep-driving.

Breastfeeding	Eszopiclone is excreted into human breast milk in low concentrations. The milk-to-plasma ratio (M/P) is approximately 0.53. Peak milk concentration occurs about 1-1.5 hours after maternal dose. Caution is advised; monitor infant for excessive sedation, poor feeding, or respiratory depression. Alternative agents preferred.
Teratogenic Risk	Eszopiclone is classified as FDA Pregnancy Category C. Limited human data; animal studies have shown adverse effects. In the first trimester, there is potential risk of major malformations, although data are insufficient to quantify. Second and third trimester exposure may be associated with decreased fetal growth and respiratory depression. Use only if benefit outweighs risk.

Warnings & precautions

■ FDA Black Box Warning

None (no FDA boxed warning)

Side Effect Profile

Common Effects	Unpleasant taste
Serious Effects

Absolute Contraindications

["Hypersensitivity to eszopiclone","History of complex sleep behaviors with previous use","Severe hepatic impairment (Child-Pugh class C)","Concurrent use of other CNS depressants (relative contraindication)","Severe respiratory insufficiency (relative contraindication)"]

Clinical Precautions

Precautions

["Central nervous system depressant effects (risk of impaired alertness and motor coordination)","Complex sleep behaviors (sleep-driving, preparing/eating food, making phone calls)","Anaphylaxis and angioedema (rare)","Behavioral changes (somnambulism, hallucinations, aggression)","Dependence and withdrawal (tolerance, addiction with abrupt discontinuation)","Elderly patients (increased fall risk, cognitive impairment)","Respiratory depression (caution in COPD, sleep apnea)"]

Clinical Tips & Counseling

Drug interactions

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