1 Zopiclone Overdose

Overdoses are a serious thing.

Overdoses can be either accidental, intentional, or deliberate [1]. 

Overdosing on drugs, such as prescription medications can be fatal.

However, individuals who do overdose can be revived, if proper medical treatment is available [1]. 

The most common type of death due to a fatal overdose is usually respiratory failure [2]

Zopiclone Overdoses

With regards to benzos, patients who accidentally or intentionally overdose from benzos suffer from central nervous system (CNS) depression [3].

In addition, symptoms of overdose can include:

• Slurred speech
• Altered mental state
• Loss of bodily movements (ataxia)

There have been numerous documented incidents of zopiclone overdose, which involved overdosing on “7.5mg zopiclone” [31].

These cases, although extreme, can still happen if one misuses or increases a prescribed zopiclone dose.

Extremely high doses of zopiclone should ALWAYS be avoided [8]

Mild cases of zopiclone overdose include:

• Drowsiness 
• Confusion
• Lethargy 

More severe overdose symptoms, include:

• Hypotonia
• Hypotension 
• Respiratory depression 
• Coma 

Importantly, the overdose effects of zopiclone can be greatly inflated if mixed with other central nervous system (CNS) depressants, and alcohol [4].

Moreover, if someone already has an existing medical issue, including the already possible debilitated state of a patient, then this might contribute to the severity of symptoms [4]. 

Discussing drug overdose is never an easy topic. 

Below examples of documented cases of zopiclone misuse that have caused severe and sometimes life-threatening outcomes.

One case study reported the zopiclone overdose of a 27 year-old man who was an athlete and who suffered from migraines [6].

Zopiclone was recorded in the individuals blood at a concentration of 0.073mg/L after 4.25 hours, which is a high amount of zopiclone in the blood.

Results

The man was found to be unresponsive, after he had ingested 14 – 20 (7.5mg) zopiclone tablets [6]. 

In addition, the individual showed high blood pressure, and was slow to respond to commands by paramedics.

Discussion

Paramedics were able to stabilize the individual, once Flumazenil was administered.

No doubt, the amount of zopiclone tablets this individual consumed was, of course, extremely high. 

Although it is not recommended to mix medications with other (recreational) substances, the reason this is usually stressed is because these drug interactions can be life-threatening [8]. 

Some dangerous drug interactions with zopiclone might include:

• Depressants: combination of zopiclone with depressants could result in fatal levels of respiratory depression. High zopiclone doses will lead to loss of consciousness, which is extremely dangerous. This can ultimately lead to a risk of vomiting during unconsciousness, and suffocation.

• Dissociatives: these drugs are known for causing distortions of the senses. These types include PCP, ketamine, and DXM. Combing dissociatives with zopiclone can lead to an increased risk of vomiting and even suffocation.

Determining the interaction of a drug, such as zopiclone with other well-established marketed drugs is often difficult to fully understand. 

Drug interactions can have varying effects across individuals.

The table below gives an indication of the classification of drug interactions that exist.

These should be taken as a guide only.

Table adapted from https://www.drugs.com/drug-interactions/sertraline,zoloft.html. 

Sticking with our different types of drug interactions (table above).

Let’s now look at some known, and not so well-known drug interactions with zopiclone. 

Table 1. Listed drugs and their interaction with zopiclone, zolpidem and zaleplon. Although there may be interactions with zolpidem and zaleplon, there is little evidence at present to suggest a direct interaction.

Zopiclone and diazepam interactions have not been extensively studied.

Finding appropriate literature has been hard to come by. 

However, in one study, 7.5mg zopiclone (standard dose), 1mg lorazepam and 5mg diazepam were given to patients, and psychomotor performance was assessed up to 24 hours after the initial administration [12]. 

Results

Data showed that only one hour after administration, psychomotor performance was impaired [12]. 

Conclusions

Importantly, the researchers concluded that zopiclone did not modify the pharmacokinetics of diazepam dose [12]. 

Meaning, zopiclone did not have an effect on the dynamics of diazepam in their study. 

Promethazine is known as a first-generation antihistamine, and is used to treat allergy symptoms like an itchy nose, watery eyes, etc [14]. 

Zopiclone and promethazine has yet to be comprehensively studied in its combination.

Further research will allow people to better understand this drug interaction. 

For better insight into this interaction, consult your doctor.

One study tested the potential differences of providing a “good night’s sleep” in patients who had stroke and brain injury [16], and who were also suffering from insomnia.

Patients were administered between 0.5-1.0mg lorazepam and zopiclone at doses between 3.75 and 7.5mg [16] for 7 days. 

Results 

The study reported that zopiclone and lorazepam were equally good as treatments for insomnia in these patients [16]. 

Conclusions

The fact that this study was conducted, may indicate that Zopiclone and Lorazepam may be administered together without serious risk of harm – so long as strict procedure, dosage and monitoring is done. 

Pregabalin, which is marketed as Lyrica, is an anti-epileptic drug which works by slowing down impulses in the brain that may cause seizures [17]. 

One study found that Zopiclone and pregabalin were attributed with overdose death [18]. 

In this regard, it is advisable to avoid mixing zopiclone and pregabalin.

Tramadol is used by individuals as an analgesic agent, used to treat mild pain [19]. 

More research is needed to confirm any interactions between zopiclone and tramadol as to better inform people on these two drugs.

Anecdotal evidence seems to suggest that it is not recommended to take these two medications as combination. 

Individual cases on this combination of zopiclone and tramadol also recommend consulting your doctor or pharmacy [29]. 

Sertraline (Zoloft) is anothantidepressant drug that is known in the class of serotonin reuptake inhibitors (SSRI), and is often used to treat depression [22]. 

The FDA has noted that sertraline is used by individuals to treat depression and other mood disorders [23]. 

Although not fully reported in the scientific literature, it is important not to mix sertraline with other medications, such as zopiclone, as these drugs may interfere and cause unwanted effects.  

Drug interactions between zopiclone and marijuana (weed) have not been fully studied and investigated, so many people are not aware of the potential interactions.

In the UK, medicinal cannabis has now been legalised, since November 2018 [29]. Making research, at this early stage, rather thin.

However, the z-drug zolpidem has been implicated in its effects in cannabis withdrawal – also known as cannabis use disorder (CUD) [27]. Zolpidem is similar to zopiclone as it is also a z-drug and is also used to treat insomnia. 

In fact, researchers used a placebo-controlled model of assessing zolpidem for cannabis withdrawal during abstinence, along with mood, sleep and food intake. 

Used on its own, zolpidem in participants reduced sleep disturbance, however did not lead to alleviation of other withdrawal symptoms [27]. It would be advisable to consult your doctor before ingesting zopiclone and cannabis. 

Zopiclone and alcohol should NOT be mixed in any circumstances. 

It will, most likely cause difficulties associated with cognition and respiration [9] which can both be life-threatening.

Other effects induced by combining alcohol with zopiclone can include:

• Sleepwalking
• Eating food [10].

Also, combining alcohol with zopiclone can lead to a lack of judgment, sexual disinhibition and fatal overdose [11]. 

Clonazepam, classed as a benzo, is used as an adjunct therapy to control and even prevent seizures in individuals [24;26]. 

An adjunct therapy is one that is used together with primary therapy in the hopes to assist the primary treatment.

Important to take note here is that there are approximately 431 known drug interactions with clonazepam, with 26 major interactions [25].

It is not clear as to the extent of interaction between zopiclone and clonazepam; so, more research is needed.

One report states that mixing zolpidem with clonazepam can cause side effects like drowsiness, dizziness and difficulty focusing and concentrating [26].

For more information regarding benzos, check out our short history of benzodiazepines article.

1. https://www.webmd.com/mental-health/addiction/drug-overdose#1
2. https://www.addictioncenter.com/drugs/overdose/].
3. https://www.ncbi.nlm.nih.gov/books/NBK482238/
4. https://www.medsafe.govt.nz/Profs/Datasheet/z/zopicloneactavistab.pdf
5. http://drugfacts.org.uk/index.php?title=Zopiclone
6. https://www.tandfonline.com/doi/pdf/10.1081/CLT-200058944
7. https://www.tandfonline.com/doi/abs/10.3109/15563650903313541
8. http://drugfacts.org.uk/index.php?title=Zopiclone
9. https://chealth.canoe.com/drug/getdrug/pms-zopiclone
10. https://www.netdoctor.co.uk/medicines/brain-nervous-system/a7792/zimovane-zopiclone/#alcohol
11. https://bpac.org.nz/Audits/insomnia.aspx
12. https://www.ncbi.nlm.nih.gov/pubmed/1508840
13. https://jmedicalcasereports.biomedcentral.com/articles/10.1186/1752-1947-4-403
14. https://www.drugs.com/promethazine.html
15. https://www.ncbi.nlm.nih.gov/pubmed/11015032 

16.https://journals.lww.com/ajpmr/Abstract/2004/06000/Comparison_of_Lorazepam_and_Zopiclone_for_Insomnia.3.aspx

17. https://www.drugs.com/mtm/pregabalin.html
18. https://www.sciencedirect.com/science/article/pii/S0376871617300856
19. https://www.sciencedirect.com/science/article/pii/S0379073803001002
20. https://www.drugs.com/zoloft.html 
21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662142/ 
22. https://www.nhs.uk/medicines/sertraline/ 
23. https://www.medicalnewstoday.com/articles/325632.php#uses 
24. https://www.webmd.com/drugs/2/drug-14403-6006/clonazepam-oral/clonazepam-oral/details 
25. https://www.drugs.com/drug-interactions/clonazepam.html 
26. https://www.ncbi.nlm.nih.gov/books/NBK548030/
27. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5302052/
28. https://www.drugwise.org.uk/what-are-the-uk-drug-laws/
29. https://patient.info/forums/discuss/tramadol-and-zopiclone–506395
30. https://pdfs.semanticscholar.org/5ed4/0519f326953153590b66c0260bb99024dfd8.pdf
31. https://www.reddit.com/r/AskReddit/comments/cibeu/i_tried_to_overdose_on_21_tablets_of_zimovane/