Imovane (Zopiclone)

Zopiclone is a non‑benzodiazepine hypnotic used in the management of sleep disorders.

• Insomnia: improves sleep onset and reduces nighttime awakenings in patients with short‑term insomnia.
• Difficulty falling asleep: shortens sleep latency, helping patients fall asleep faster.
• Difficulty maintaining sleep: decreases the number of awakenings and prolongs total sleep time.

• Zopiclone acts as a positive allosteric modulator at the benzodiazepine binding site of the GABA‑A receptor complex. By binding to this site, it enhances the inhibitory effect of the neurotransmitter GABA, increasing chloride ion influx and hyperpolarising neuronal membranes. This potentiation of GABA‑mediated neurotransmission leads to reduced neuronal excitability, producing sedative and hypnotic effects that facilitate sleep.

Zopiclone may cause a range of adverse reactions, which are categorised by frequency and severity.

Common Side Effects

• Drowsiness: feeling of sleepiness during the day.
• Dry mouth: reduced salivation leading to throat discomfort.
• Bitter taste: unpleasant metallic taste in the mouth.
• Dizziness: light‑headed sensation, especially when standing quickly.

Serious or Rare Side Effects

• Complex sleep behaviours: activities such as sleep‑walking, sleep‑driving or eating while not fully awake.
• Allergic reactions: rash, itching, swelling or difficulty breathing indicating possible hypersensitivity.
• Memory impairment: anterograde amnesia for events occurring after dosing.
• Mood changes: emergence of depression, anxiety or suicidal thoughts.

When prescribing Zopiclone, several safety considerations should be observed to minimise risk.

• Assess need for short‑term therapy: limit use to a few weeks as recommended.
• Avoid alcohol: concurrent consumption may intensify sedation and respiratory depression.
• Monitor elderly patients: increased risk of falls, confusion and cognitive impairment.
• Evaluate renal or hepatic impairment: dose adjustment may be required in reduced function.
• Consider pregnancy and lactation: use only if potential benefits outweigh risks.
• Store at ambient temperature: keep below 25 °C in the original packaging, protected from moisture.

Zopiclone can interact with other medicines, altering its effectiveness or safety profile.

Major Interactions (Avoid)

• Alcohol: additive central nervous system depression may cause severe sedation or respiratory compromise.
• CYP3A4 inhibitors (e.g., ketoconazole, erythromycin): increase plasma concentrations, raising the risk of toxicity.
• Other CNS depressants (opioids, antihistamines, benzodiazepines): may lead to profound sedation and impaired psychomotor function.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce Zopiclone levels and diminish efficacy.
• Selective serotonin reuptake inhibitors (e.g., fluoxetine): can modestly increase sedation.
• Antidepressants with sedating properties (e.g., trazodone): may enhance hypnotic effect and require dose adjustment.