What happens when zopiclone is mixed?

Zopiclone is a prescription sleeping tablet used for the short-term treatment of insomnia. It is sometimes called a "Z-drug" or hypnotic medicine. It works by increasing the effect of calming chemical signals in the brain, helping a person fall asleep and remain asleep. The NHS says zopiclone usually starts working within 30 to 60 minutes and is generally prescribed for only a few days or weeks because tolerance, dependence and addiction can develop.

The central concern is that zopiclone slows activity in the central nervous system. Alcohol and several other medicines and recreational drugs can produce a similar sedative effect. When these substances are taken together, their effects may add up or become less predictable.

This can lead to:

•  Extreme sleepiness or loss of consciousness.
•  Confusion, poor judgement and impaired coordination.
•  Falls, accidents and injuries.
•  Memory loss or unusual behaviour while not fully awake.
•  Vomiting while heavily sedated, creating a choking risk.
•  Slow, shallow or difficult breathing.
•  Coma and, in severe cases, death.

The combination is not made safe by taking a small amount of alcohol, using a lower tablet strength or waiting until a person feels sleepy. Individual responses vary according to body size, age, tolerance, liver and lung health, the amount taken and what else is in the person's system.

The NHS specifically advises people not to drink alcohol while taking zopiclone because alcohol can increase the medicine's effects, cause breathing problems and make it very difficult to wake up. The UK product information also states that combining zopiclone with alcohol is not recommended because sedation and impairment may be enhanced.

There is no universal "safe gap" that guarantees alcohol and zopiclone will not interact. Alcohol can remain in the body for several hours, and the risks are higher if other sedating substances have also been used.

Drugs that can increase the danger

"Other drugs" includes prescribed medicines, over-the-counter products, illegal substances and pills bought online. A person may not realise that a medicine is sedating, particularly if it was prescribed for pain, anxiety, allergies or another health condition.

Opioid painkillers and heroin

Opioids include codeine, morphine, oxycodone, tramadol, methadone, fentanyl and heroin. Combining an opioid with zopiclone can produce profound sedation and suppress breathing. The UK product information warns that zopiclone taken with opioids may increase the risk of sedation, respiratory depression, coma and death.

This risk may be even more difficult to judge when an opioid is obtained illegally or when a tablet contains an unexpected substance. Never assume that a familiar-looking pill contains what its packaging claims.

Benzodiazepines and other sleeping tablets

Examples include diazepam, lorazepam, temazepam, clonazepam and alprazolam. Other sleeping medicines, including zolpidem, may also have additive sedative effects. Taking more than one medicine for sleep, anxiety or agitation should only happen if a prescriber has specifically instructed it.

Combining zopiclone with a benzodiazepine can cause excessive drowsiness, confusion, memory problems, poor balance and slowed breathing. Alcohol can intensify the effect further.

Pregabalin and gabapentin

Pregabalin and gabapentin are prescribed for conditions such as nerve pain, epilepsy and anxiety. They can cause drowsiness and dizziness. When taken with zopiclone, alcohol or opioids, the combined sedative effect may become stronger.

People with breathing disorders, sleep apnoea, chronic lung disease or a history of substance dependence may be particularly vulnerable. Tell a doctor or pharmacist about all medicines, including those obtained privately or online.

Sedating antihistamines

Some allergy, cough and travel-sickness medicines can make people sleepy. Examples include promethazine and chlorphenamine. The NHS lists sedating antihistamines among medicines that may not mix well with zopiclone.

A product sold for hay fever or a night-time cold may therefore add to the effects of a sleeping tablet. Read the label carefully and ask a pharmacist before taking an over-the-counter medicine with zopiclone.

Antipsychotics, antidepressants and anti-epileptic medicines

Some medicines used for mental health conditions, mood disorders or epilepsy may add to central nervous system depression. Not every medicine in these categories has the same effect, so do not stop or change prescribed treatment without medical advice.

The UK product information advises that the potential benefit and risk of combining zopiclone with antipsychotics, antidepressants, anti-epileptic medicines, anaesthetics and other sedatives should be carefully considered.

Cannabis, illicit drugs and unknown pills

Cannabis may increase drowsiness, poor coordination and impaired judgement when combined with a sleeping tablet. Other recreational drugs can also create unpredictable risks, especially if a person takes a stimulant and assumes it will "cancel out" the sedative effect.

Unknown powders, tablets and counterfeit medicines are particularly hazardous because their ingredients and strength may be unclear. Mixing drugs is never reliably safe simply because the substances were used on different occasions or in small quantities.

Symptoms of a dangerous reaction

A person who has combined zopiclone with alcohol or other drugs may initially appear merely tired. Their condition can worsen as the substances continue to take effect, so do not rely on the person being able to say that they feel fine.

Possible warning signs include:

• Slurred speech or inability to answer questions clearly.
• Unusual confusion, agitation or disorientation.
• Difficulty standing, walking or coordinating movements.
• Repeatedly falling asleep or being impossible to wake fully.
• Very slow, shallow, noisy or irregular breathing.
• Blue, grey or pale lips or fingertips.
• Vomiting while drowsy or unconscious.
• Loss of consciousness.
• A seizure or fit.
• Breathing stopping.

Zopiclone can also cause short-term memory loss and, rarely, complex sleep behaviours such as sleepwalking, eating, making phone calls or driving while not fully awake. The person may have no memory of what happened afterwards. Alcohol and other central nervous system depressants may increase the risk of these behaviours.

What to do in an emergency

Call 999 or go to A&E if the person has lost consciousness, stopped breathing, has severe difficulty breathing or is having a seizure. The NHS treats suspected poisoning involving medicines, alcohol or drugs as a reason to seek urgent medical advice.

While waiting for help:

• Check that the area is safe for you to enter.
• Tell the 999 call handler exactly what the person may have taken, if known.
• If they are unconscious but breathing normally, place them on their side in the recovery position.
• Keep checking their breathing and responsiveness.
• If they are not breathing normally, call 999 and start CPR, following the call handler's instructions.
• Keep packets, bottles, blister strips or other containers for the ambulance crew.
• Stay with the person and do not let them "sleep it off" alone.

Do not make the person vomit and do not give them food, drink, coffee or another drug to try to wake them. The NHS warns that making someone sick can cause choking, while food and drink may be unsafe if they are drowsy.

If the person is awake and you are unsure whether the amount taken is harmful, call NHS 111 for urgent advice. Do not drive yourself to A&E after taking zopiclone or other sedatives. Ask someone else to take you or call 999 if an ambulance is needed. Bring the medicine packaging and details of any alcohol or drugs involved.

If opioids may be involved and naloxone is available, tell the 999 call handler and follow their instructions. Naloxone can reverse opioid effects, but it does not remove the danger from zopiclone, alcohol or other non-opioid sedatives. Emergency medical assessment is still essential.

Driving, dependence and prevention

Zopiclone can affect alertness and coordination the following day. The NHS advises people not to drive, cycle or use machinery for 12 hours after taking it, and to wait longer if they still feel sleepy, dazed or less alert. Alcohol and other sedatives can make next-day impairment more likely.

Do not take an extra zopiclone tablet because the first one seems ineffective. The medicine should be taken as prescribed, in one dose before bed, and not repeated during the same night. Taking more than the prescribed amount can be dangerous, even if the person does not yet have symptoms.

Zopiclone can lead to physical or psychological dependence. Stopping suddenly after regular use may cause withdrawal symptoms, including anxiety, agitation, sweating, tremor, confusion, rebound insomnia and, rarely, seizures. The NHS advises speaking with a doctor because the dose may need to be reduced gradually rather than stopped abruptly.

Prevention is straightforward but important:

• Do not drink alcohol while taking zopiclone.
• Do not share tablets or use someone else's prescription.
• Tell your doctor and pharmacist about every medicine, supplement and recreational drug.
• Avoid buying sleeping tablets from unverified websites.
• Store zopiclone securely and follow the prescribed dose.
• Ask for a medication review if you feel you need a higher dose or use it more often.
• Seek help early if alcohol, sleeping tablets or other drugs are becoming difficult to control.