Adult: For short-term management: 7.5 mg shortly before bedtime. Dose may be reduced to 3.75 mg depending on clinical response. Use the lowest effective dose for the shortest possible duration. Max treatment duration: 4 weeks (including tapering off period). Elderly: For short-term management: Initially, 3.75 mg shortly before bedtime, may be increased to 7.5 mg depending on clinical response. Use the lowest effective dose for the shortest possible duration. Max treatment duration: 4 weeks (including tapering off period).
Special Patient Group
Debilitated patients or patients with chronic respiratory insufficiency: Initially, 3.75 mg shortly before bedtime, may be increased to 7.5 mg depending on clinical response. Use the lowest effective dose for the shortest possible duration. Max treatment duration: 4 weeks (including tapering off period).
Renal Impairment
Initially, 3.75 mg shortly before bedtime. Use the lowest effective dose for the shortest possible duration. Max treatment duration: 4 weeks (including tapering off period).
Hepatic Impairment
Mild to moderate: Initially, 3.75 mg shortly before bedtime, may be increased to 7.5 mg with caution, if necessary. Use the lowest effective dose for the shortest possible duration. Max treatment duration: 4 weeks (including tapering off period). Severe: Contraindicated.
Administration
May be taken with or without food.
Contraindications
Myasthenia gravis, severe sleep apnoea syndrome, respiratory failure, history of complex sleep behaviours after zopiclone administration. Severe hepatic impairment.
Special Precautions
Patient with history of psychiatric disorder; chronic respiratory insufficiency; personal or family history of sleepwalking or other disorders that may affect sleep (e.g. restless leg syndrome, periodic limb movement disorder); depression, current or history of alcohol or substance abuse. Not recommended for continuous long-term use. Avoid abrupt withdrawal and rapid dose reduction. Renal and mild to moderate hepatic impairment. Elderly and debilitated patient. Pregnancy and lactation.
Adverse Reactions
Significant: Abnormal thinking and behavioural changes (e.g. restlessness, aggression, bizarre behaviour, agitation, hallucinations, decreased inhibition, depersonalisation); rebound insomnia (following discontinuation), anterograde amnesia, CNS depression; suicidal ideation and attempts; physical and psychological dependence and/or abuse; withdrawal syndrome (particularly after abrupt discontinuation or rapid dose reduction). Cardiac disorders: Palpitations (particularly in elderly). Eye disorders: Diplopia, blurred vision. Gastrointestinal disorders: Dry mouth, dysgeusia, nausea, vomiting, constipation, diarrhoea, halitosis. General disorders and administration site conditions: Fatigue, asthenia. Metabolism and nutrition disorders: Anorexia, increased appetite. Musculoskeletal and connective tissue disorders: Hypotonia. Nervous system disorders: Somnolence, dizziness, headache, ataxia, paraesthesia, tremor. Psychiatric disorders: Nightmares. Reproductive system and breast disorders: Change in libido. Respiratory, thoracic and mediastinal disorders: Dyspnoea. Potentially Fatal: Complex sleep behaviours (e.g. sleepwalking, sleep-driving). Rarely, anaphylaxis and angioedema (involving the tongue, glottis or larynx).
Patient Counseling Information
This drug may impair physical and mental abilities, if affected, do not drive or operate machinery.
Monitoring Parameters
Observe for confusion, excessive drowsiness (particularly in the elderly), and respiratory depression. Closely monitor patients with hepatic impairment or chronic respiratory insufficiency.
Overdosage
Symptoms: Mild cases: Drowsiness, confusion, lethargy. Severe cases: Ataxia, hypotonia, hypotension, methaemoglobinaemia, respiratory depression, coma. Management: Symptomatic and supportive treatment. Ensure clear airways. Monitor cardiac and vital signs until stable. Consider administration of activated charcoal if more than 150 mg has been ingested within 1 hour or consider performing gastric lavage. Flumazenil may be considered for severe CNS depression.
Drug Interactions
Enhanced CNS depressant effect with other CNS depressants (e.g. antipsychotics, antidepressants, antiepileptics, anaesthetics, sedative antihistamines). May increase plasma concentration with CYP3A4 inhibitors (e.g. ketoconazole, itraconazole, erythromycin, clarithromycin, ritonavir). May decrease plasma concentration with CYP3A4 inducers (e.g. rifampicin, carbamazepine, phenobarbital, phenytoin). Potentially Fatal: Increased risk of sedation, respiratory depression, and coma with opioids.
Food Interaction
Enhanced sedative effect with alcohol. May decrease plasma concentration with St. John's wort.
Action
Description: Mechanism of Action: Zopiclone, a cyclopyrrolone derivative, is a short-acting hypnotic agent with a pharmacological profile similar to benzodiazepines. It binds to the gamma-aminobutyric acid (GABA) macromolecular receptor complex, but at a different site to that of benzodiazepines, leading to enhanced GABA activity in the brain. It decreases sleep latency, increases sleep duration, and reduces the frequency of nocturnal awakenings. Pharmacokinetics: Absorption: Rapidly absorbed. Bioavailability: 77%. Time to peak plasma concentration: 1.5-2 hours. Distribution: Widely distributed. Crosses the placenta and enters breast milk. Volume of distribution: 91.8-104.6 L. Plasma protein binding: Approx 45-80%. Metabolism: Extensively metabolised in the liver by the CYP3A4 isoenzyme and, to a lesser extent, by CYP2C8 isoenzyme into zopiclone N-oxide (less active) and N-desmethylzopiclone (inactive). Excretion: Via urine (approx 80% as free metabolites; approx 4-5% as unchanged drug); faeces (approx 16%). Elimination half-life: 3.5-6.5 hours.
Chemical Structure
Storage
Store below 30°C. Protect from light and moisture.