Drug Breakdown / CPD

Zopiclone

02 July 2022
Drug Breakdown
02 July 2022
Volume 4 · Issue 7

Abstract

In this column, Sharon Rees aims to refresh knowledge and interest in some of the commonly used drugs in a series of tweets. This month she is talking about #zopiclone

Dr Sharon Rees @reesprescribe

Day 1: developed as a safer alternative to benzodiazepines (BZDs), #zopiclone was the first ‘Z’ drug licensed in the UK for short-term insomnia in the 1980–90s. Gamma-aminobutyric acid (GABA) receptor complex scrutiny led to the discovery of other compounds with affinity. Despite similar effects, #zopiclone is chemically distinct from BZDs.

Dr Sharon Rees @reesprescribe

Day 1 (cont): #zopliclone#zdrugs advantages may include short half-lives and lower respiratory depression risk. Low risk of dependence/withdrawal/tolerance and rebound effects of insomnia/anxiety IF the duration of use is less than 4 weeks.

Dr Sharon Rees @reesprescribe

Day 2: #zopiclone comes in tablet form for adult use only. Once-daily night time dosing for up to 4 weeks at either 3.75 mg or 7.5 mg. A lower dose is recommended in the elderly because of the risk of falls/accidents and also if there is chronic respiratory failure (contra-indicated if severe).

Dr Sharon Rees @reesprescribe

Day 3: kinetics; good oral absorption and bioavailability with a high volume of distribution. Extensive liver metabolism via CYP3A4 and CYP2C8 produces two active (weak) metabolites; caution/reduce the dose or avoid if hepatic impairment. 80% renal excretion of metabolites. No relevant accumulation in repeat dosing (even in elderly/renal impairment). Crosses the placenta and is excreted into breast milk. Avoid during pregnancy and when breastfeeding. T½ 5–6 hrs.

Dr Sharon Rees @reesprescribe

Day 4: #zopiclone modulates the GABAA receptor complex leading to the opening of the chloride channel at a different site to benzodiazepines (BZDs). A higher frequency of channel opening combined with high affinity in brain sleep function areas leads to a hypnotic effect. This is believed to mirror physiological sleep patterns more closely than BZDs. #zopiclone has anxiolytic, muscle relaxant and anti-convulsant properties, but is licensed only for insomnia.

Dr Sharon Rees @reesprescribe

Day 5: #zopiclone common ADEs include bitter taste and dry mouth. Serious/rare: anaphylaxis, withdrawal reactions, psychiatric disorders (NOT exhaustive). Residual sedation can cause driving risks and psychomotor/cognitive impairment can cause falls/accidents. #zopiclone linked with increased ED visits.

Dr Sharon Rees @reesprescribe

Day 6: #zopiclone has no drug-drug interaction classed as ‘severe’. All drugs with CNS depressant activity can potentiate effect. Enzyme inhibitors eg macrolides, fluconazole can increase exposure and inducers eg phenytoin can reduce drug action (NOT exhaustive).

Dr Sharon Rees @reesprescribe

Day 7: In the UK, #zdrugs such as #zopiclone are all class C controlled drugs. They are under schedule 4 in UK and US (light regulation). #zopiclone (racemic mix) is not licensed in US, but the S-enantiomer eszopiclone is licensed in the US, as is zolpidem.

EARN YOUR CPD CERTIFICATE

With the help of Prescribing and Therapeutics Training Ltd and the Journal of Prescribing Practice, you can earn your 1-hour CPD certificate

In addition to the tweets, read the BNF treatment summaries on hypnotics and anxiolytics and the monograph for zopiclone. Another useful source is the summary of product characteristics for zopiclone. Complete the additional reading suggested below and then answer the 10 questions.

Please submit the answers to reesprescribe@gmail.com as a numbered list with TRUE/FALSE or the correct A,B,C,D option. If you achieve 8 or more out of ten on the questions, a CPD certificate will be emailed to you.

The licensed indications for zopiclone mirror that of benzodiazepines

TRUE or FALSE?

Which of the following is TRUE?

  • Zopiclone is a type of benzodiazepine
  • Zopiclone has opioid-like properties
  • All Z drugs, including zopiclone, are controlled drugs
  • Z drugs are licensed for long-term use

Which of the following is FALSE regarding the advantages of Z drugs compared to benzodiazepines?

  • Z drugs are more addictive
  • Z drugs have short half-lives, limiting residual sedation
  • There is a lower risk of dependence with Z drugs
  • There is a lower risk of respiratory depression with Z drugs

The kinetics of zopiclone mean there is a risk of reduced clearance in hepatic impairment.

TRUE or FALSE?

Zopiclone is not recommended for use in pregnancy or breastfeeding.

TRUE or FALSE?

Which of the following is a contraindication for zopiclone use?

  • Epilepsy
  • Severe sleep apnoea syndrome
  • Elderly
  • Any grade of hepatic impairment

Zopiclone increases the activity of the GABAA receptor.

TRUE or FALSE?

Which of the following is a common adverse drug event for zopiclone?

  • Anaphylaxis
  • Metallic taste
  • Cognitive impairment
  • Skin reactions

Zopiclone has many severe drug-drug interactions.

TRUE or FALSE

Zopiclone is not licensed in the US.

TRUE or FALSE

Further reading on #zopiclone

More Drug Breakdowns: clopidogrel