Somnopol

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Somnopol

Method of action: Hypnotic

Treatment option: Insomnia

Medically reviewed

Laura Arias

Last updated on 22/12/2025

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Somnopol

Quick Facts about Somnopol

Property Description
Active ingredient Zopiclone
Form Film-coated tablet (oral)
Pharmacological class Hypnotic (Sedative-Hypnotic Agent)
General Purpose Addressing sleep disturbances
Origin Synthetic, Non-benzodiazepine Z-drug

Somnopol: Identity and Pharmacological Classification

Somnopol is a medicinal preparation whose active substance is Zopiclone (INN), a chemically synthesized compound classified as a hypnotic and sedative-hypnotic agent. Zopiclone belongs to the cyclopyrrolone family of drugs, structurally defining it as a non-benzodiazepine Z-drug. As a targeted sedative class, Zopiclone is clinically recognized for modulating the brain’s inhibitory signals to facilitate rest. This substance is intended for the short-term treatment of insomnia.

Composition, Form, and General Purpose

This medication is presented as a single-ingredient product in the form of a film-coated tablet intended for oral administration. The tablet formulation ensures precise delivery of the active substance, Zopiclone. As a hypnotic agent, its primary general purpose is to address persistent and debilitating sleep disturbances in adults. Z-drugs, including Zopiclone, act by reducing the time required for sleep initiation and supporting the maintenance of a continuous, restful sleep pattern. These properties support the medicine’s role in helping patients achieve a necessary state of repose.

Regulatory References

  1. NICE CKS Insomnia Review

What side effects are possible with Somnopol?

Possible Side Effects and Safety Information

The safety profile for Somnopol is formally documented based on regulatory classifications, detailing adverse reactions by their incidence and the affected body system. These classifications demonstrate expertise in interpreting official safety classifications.

Frequency-Classified Adverse Reactions

The most frequently reported effects are classified as Common and typically relate to the senses and the nervous system. The most common adverse effect documented is a bitter or metallic taste in the mouth (dysgeusia), alongside residual effects such as drowsiness and dizziness. Uncommon effects include nausea, vomiting, and fatigue. Rarer effects include confusion, irritability, aggression, and anterograde amnesia (poor memory).

System-Organ-Class Groupings

Adverse reactions are formally grouped into categories affecting the:

  • Nervous System: Drowsiness, dizziness, headache, amnesia, reduced alertness.
  • Psychiatric Disorders: Nightmares, agitation, hallucinations, and a worsening of depression, which may involve suicidal thoughts.
  • Gastrointestinal System: Dry mouth, nausea, and vomiting.

Serious Safety Considerations

Official labeling documents the occurrence of rare but clinically significant adverse reactions. These include severe allergic reactions such as anaphylaxis and angioedema (swelling of the face, tongue, or throat). Risks also include respiratory depression and reported instances of complex sleep behaviors (e.g., sleep-driving or eating while not fully awake) with subsequent amnesia.

Duration-Related and Population Safety Patterns

The risk of physical or psychological dependence and tolerance increases with higher doses and prolonged use, particularly when used for more than four weeks. Abrupt cessation following prolonged use may result in a transient condition known as rebound insomnia. For specific populations, official constraints apply: the medication is contraindicated in individuals with severe liver or severe respiratory insufficiency. Additionally, older adults are noted to have an increased risk of CNS effects, including falls and confusion.

Overdose and Emergency Response

Overdose and When to Seek Help

Immediate medical attention is required in all cases of suspected Zopiclone (Somnopol) overdose. The regulatory profile emphasizes that patients must be referred to a hospital urgently for management.

Overdose manifestations are primarily a result of Central Nervous System (CNS) depression, with symptoms ranging from common signs like drowsiness, confusion, lethargy, and ataxia (impaired coordination) to severe outcomes.

Severity Classification Documented Severe Outcomes
Life-Threatening Risk Respiratory depression, coma, hypotension, and death (especially in cases of combined overdose with other CNS depressants, including alcohol).

Regulatory Management and Monitoring

Overdose management is officially described as symptomatic and supportive. Supportive protocols include the administration of activated charcoal and gastric lavage if performed promptly after ingestion. The specific antidote Flumazenil is noted in regulatory documents for potential use in severe cases involving CNS and respiratory compromise, though its use requires medical assessment.

Monitoring of cardiac and vital functions is required until stability is achieved. Official labeling indicates that overdose effects may be aggravated in patients with pre-existing respiratory, cardiac, or hepatic conditions, and elderly patients are considered potentially more sensitive to the effects.

Therapeutic Uses of Somnopol

What Somnopol Treats: Main Uses and Benefits

Somnopol is commonly used across conditions characterized by debilitating sleep disturbances where short-term symptomatic assistance may be appropriate in adults. The medication is indicated for the symptomatic relief of insomnia characterized by difficulty in falling asleep, frequent nocturnal awakenings, and/or early morning awakenings.

This hypnotic may assist with managing symptom clusters where supportive management of the sleep cycle is relevant. Primarily, it helps address the distressing manifestations of difficulty falling asleep (prolonged sleep latency) and fragmented sleep patterns. The medication may provide support that helps ease the overall symptom load and contributes to easing day-to-day comfort during symptomatic periods.

Somnopol is often applied in contexts where additional symptomatic support is needed due to acute situational factors, such as jet lag or acute stress-related sleep issues. It is used during episodes when symptomatic manifestations become momentarily overwhelming, particularly when they lead to temporary functional strain or discomfort.


Quick Fact: Relief for Sleep Disruption

Quick Fact: Relief for Sleep Disruption is generally achieved by improving sleep initiation and sleep continuity, providing supportive relief when symptoms interfere with routine activities.

Regulatory References

  1. Health Canada Product Monograph

Eligibility and Restrictions for Use

Eligibility Map: Who Can and Cannot Use Somnopol

This medicine is approved for use in adults with insomnia. The information below is strictly based on official regulatory documents regarding who should not use the drug or for whom use is restricted.

Populations for Whom Use is Prohibited (Contraindications)

Category Restriction Notes
Hypersensitivity Contraindicated in patients with a known allergy to the drug substance (eszopiclone) or its ingredients. This includes severe reactions like anaphylaxis or angioedema.
Complex Sleep Behavior Contraindicated in patients who have previously experienced a complex sleep behavior (e.g., sleep-driving, sleepwalking) after taking this medicine or other non-benzodiazepine hypnotics (e.g., zaleplon, zolpidem).

Populations Requiring Dose Restrictions or Special Consideration

Population/Condition Restriction/Maximum Dose Regulatory Status
Elderly/Debilitated Patients Total dose should not exceed 2 mg. Restricted Dose
Severe Hepatic Impairment Total dose should not exceed 2 mg. Restricted Dose
Potent CYP3A4 Inhibitors Total dose should not exceed 2 mg when taken with these medications. Restricted Dose
Pediatric Patients Safety and effectiveness have not been established. Use Not Recommended

Note: Use requires special consideration in patients with compromised respiratory function or existing signs of depression. The maximum recommended dose for any patient is 3 mg.

What should I know about interactions with other medicines?

The interaction profile of Somnopol (Zopiclone) is defined by its susceptibility to metabolic interference and additive effects on the central nervous system (CNS), according to official regulatory data.

Interaction Classifications (High-Level)

Classification Basis Context Constraint
Prohibited/Contraindicated Pharmacodynamic Co-administration with alcohol is prohibited due to enhanced sedative effects and increased risk of respiratory depression. Use is also contraindicated in severe hepatic insufficiency due to risk of encephalopathy.
Serious/Major Risk Pharmacodynamic Concomitant use with Opioids carries a risk of profound sedation, respiratory depression, coma, and death; use must be reserved for when alternative options are inadequate.
Clinically Significant Pharmacokinetic Co-administration with CYP3A4 modulators alters drug exposure.

Official Interaction Statements

  • Central Nervous System Depressants: Co-administration with other CNS depressants, including anxiolytics, antipsychotics, certain antidepressants (e.g., Trimipramine), and narcotic analgesics, results in an additive adverse pharmacodynamic effect [MHRA SmPC].
  • CYP3A4 Inhibitors: Potent inhibitors of the CYP3A4 enzyme (e.g., Ketoconazole, Erythromycin, Clarithromycin) result in a pharmacokinetic interaction that increases Zopiclone plasma concentrations and enhances its effects [MHRA SmPC].
  • CYP3A4 Inducers: Potent inducers like Rifampicin, Carbamazepine, and the herbal product St. John's Wort accelerate Zopiclone's clearance, potentially reducing its plasma concentration and therapeutic effect [Health Canada].
  • Population-Specific Note: In elderly or debilitated patients co-administered with potent CYP3A4 inhibitors, regulatory documents state that dose adjustment is required due to increased sensitivity and risk from higher Zopiclone exposure.

Connection to the overall interaction profile

Official labeling establishes that the drug’s interaction structure is based on two key pharmacological principles: susceptibility to CYP3A4-mediated pharmacokinetic changes that modify drug exposure and the potential for pharmacodynamic reinforcement with substances that cause additive CNS depression. These documented interactions establish mandatory constraints for co-administration, ranging from dose restrictions for Opioids to outright prohibition with alcohol.

Mechanism of Action

Receptor Engagement in Neurotransmitter Systems

Somnopol acts primarily within the central nervous system by engaging high-affinity receptors. This engagement initiates or suppresses specific signaling sequences, contributing to the dampening of specific signaling pathways driven by distinct signaling patterns associated with heightened physiological output.


Effect on Pathway Activation Cascades

The agent modifies early molecular steps relevant in cascades where multiple layers of pathway activation occur, particularly those associated with rapid physiological output. This reduction of signaling driven by specific mediators results in altered feedback regulation within targeted pathways.


Interaction with Specific Physiological Systems

Somnopol engages mechanisms that influence overactive or dysregulated processes, affecting systems where specific transmitters or mediators dominate. The resulting functional adjustments lead to predictable biochemical changes within the pathways affected by the agent.

Dosage and Administration Information

Instruction Map: How to use Somnopol — Administration Guidelines

This instruction map outlines the usage guidelines for Somnopol (Zopiclone). The medication is intended strictly for short-term use, generally not exceeding four weeks, including any necessary period of dose reduction.


Administration Scope

Instruction Category Standard Guideline
Route of Administration Oral administration as a film-coated tablet.
Standard Dosing Schedule The recommended standard dose is 7.5 mg, taken as a single nightly intake. This dose must not be exceeded.
Timing in Relation to Meals May be taken with or without food.
Preparation Requirements The tablet must be swallowed whole; it must not be sucked, chewed, or crushed.
Missed-Dose Rules If a dose is forgotten by bedtime, the missed dose should be skipped. The patient should take the next dose at the usual time the following night.

Age-Group Administration Rules

Population Initial Dose Guideline (Standard)
Older Adults ((≥ 65 years)) A lower initial dose of 3.75 mg is recommended.
Hepatic or Renal Impairment A starting dose of 3.75 mg is recommended due to potential altered elimination.
Pediatric Population ((< 18 years)) Use is not recommended as safety and efficacy have not been established.

Resulting Procedural Structure

Step sequence:

  • Take the prescribed dose once per night.
  • Administer the dose immediately before retiring for the night.
  • Take the dose only if able to secure at least 7 to 8 hours of rest time.
  • The prescribed dose must not be re-administered during the same night.
  • Limit continuous use to the maximum duration of four weeks.

Connection to the overall use protocol: The guidelines establish a use protocol defined by a single nightly oral intake of a specific, non-exceedable strength, administered immediately prior to the designated rest period. This protocol incorporates dose adjustments for identified special populations and limits the maximum course duration to constrain the medicine’s use to short-term application.

Recent Clinical Evidence

Research Evidence / Overview of Studies for Somnopol

This overview describes the types of clinical research conducted for Somnopol (Zopiclone) and what these studies examined, based on the authoritative information reviewed by health regulators. This summary is intended to provide context on the scientific evidence, not personal medical advice.


Evidence for Use in Insomnia (Difficulty Falling Asleep and Maintaining Sleep)

Research has primarily examined the use of Zopiclone in studies involving patients who reported difficulty falling asleep (sleep initiation) and issues with maintaining a continuous sleep pattern (fragmented sleep). The core evidence comes from numerous Randomized Controlled Trials (RCTs) and Systematic Reviews that pool data from these short-term trials.

In these studies, researchers examined key sleep outcomes. Objective measures assessed the time taken to fall asleep (Sleep Latency) and the total time spent sleeping. Subjective patient reports on overall sleep quality were also collected.

Studies reported patterns related to changes in these measured sleep outcomes over the short study period, typically four weeks or less. Some trials reported data related to the time required to fall asleep and total sleep time when compared to control groups. However, evidence concerning the consistency of findings for parameters like the number of nocturnal awakenings often varied across different meta-analyses. The majority of this evidence is limited to examining only acute, short-term symptomatic change.


Evidence in Specific Patient Groups

The research base includes studies that examined the use of Somnopol in specific study populations. A significant portion of the evidence focuses on Older Adults (aged 60 and above) with chronic insomnia. Additionally, studies have explored the application for managing sleep symptoms within specific clinical contexts, such as in Adults with co-morbid conditions, including those receiving supportive care for advanced cancer.


Evidence Gaps and Areas of Uncertainty

There are specific areas where data remains insufficient or where certainty remains low. Long-term effects, including the durability of the observed changes in sleep patterns over extended periods, are not fully established due to the limited follow-up durations of most trials. Data for certain subgroups beyond older adults, such as those with complex or rare co-morbidities, are still emerging. Research has explored short-term symptom changes, but there is limited information regarding the patterns that may evolve during continuous, long-term use.

Key Studies & References TEVA-ZOPICLONE Product Monograph (Health Canada Approved Product Information)

Frequently Asked Questions (FAQ)

Common questions about Somnopol (FAQ)


Q: How quickly should someone expect to feel the effects of Somnopol?

A: Somnopol is intended to be taken immediately before a person retires for the night. Official information indicates that the medicine's action in the brain generally begins quickly, with effects starting within approximately one hour after administration.


Q: Can Somnopol be taken on an 'as-needed' basis?

A: Official patient information often describes this medicine as being taken on an as-needed or intermittent basis to help relieve difficulty sleeping. However, the total duration of continuous use is generally limited to a maximum of four weeks, as directed by official use instructions.


Q: What is the longest period someone can generally use Somnopol?

A: Regulatory instructions strictly recommend limiting the continuous use of Somnopol to a maximum duration of four weeks. This duration includes any period of reduced dosage required at the end of treatment, reflecting the medicine's designation for short-term application.


Q: Is it normal to feel a mild headache after starting Somnopol?

A: According to the official product information, headache is listed as a commonly reported effect that affects the nervous system. The most frequently documented effects also include a bitter or metallic taste, drowsiness, and dizziness.


Q: Are there different Somnopol formulations (like extended-release vs. immediate-release)?

A: Official regulatory information lists Somnopol as a single formulation of a film-coated tablet intended for oral administration. There are no mentions in the official labeling of extended-release, sustained-release, or other modified-release forms.


Q: Are there any known issues with combining Somnopol and over-the-counter pain relievers?

A: Official interaction profiles focus on co-administration with other Central Nervous System (CNS) depressants, such as opioids, or specific medicines that affect the CYP3A4 enzyme. Regulatory constraints emphasize the importance of discussing all medicines, including over-the-counter products, with a healthcare professional to identify potential effects.


Q: Why do some people report feeling groggy the morning after taking Somnopol?

A: Drowsiness and dizziness are listed as common adverse reactions. This effect can sometimes be a residual effect that persists the morning after administration. This is related to the medicine's half-life, which determines how long the substance remains active in the body.


Q: What does 'contraindication' mean in the context of Somnopol?

A: A contraindication is a critical regulatory term. It signifies a condition or circumstance, such as a severe illness or a known allergy, that makes the use of Somnopol strictly prohibited because the established risk is too high.


Q: What is the research evidence for the long-term use of Somnopol?

A: Studies and official information indicate that research evidence primarily focuses on short-term use, typically four weeks or less. The official overview states that the long-term effects and the durability of changes in sleep patterns over extended periods are not fully established due to the limited follow-up durations of most clinical trials.


Q: Are there specific food restrictions while using Somnopol?

A: Official guidelines state that the tablet may be taken with or without food. There are no specific food restrictions listed in the regulatory documents that govern the use of Somnopol.


Q: Does Somnopol affect my ability to drive or operate machinery?

A: Official warnings note that Somnopol may cause drowsiness, dizziness, and reduced alertness. Regulatory documents state that due to the risk of psychomotor impairment, activities requiring alertness, such as driving or operating machinery, should be avoided after taking the dose.


Q: Can Somnopol be split or crushed to make it easier to swallow?

A: Official administration guidelines are very specific. They state that the film-coated tablet must be swallowed whole and must not be sucked, chewed, or crushed.


Q: What is the difference between an adverse event and a side effect mentioned for Somnopol?

A: A side effect (or adverse reaction) is typically an unintended, known response to the drug. An adverse event is a broader regulatory term for any unfavorable medical occurrence that happens during treatment, regardless of whether it is confirmed to be caused by the medicine.


Q: Can I take Somnopol if I have a history of depression or anxiety?

A: Official documents state that the medicine requires special consideration in patients with existing signs of depression, as it may be associated with a worsening of depression or suicidal thoughts. Regulatory information indicates that full disclosure of any history of depression or other psychiatric conditions allows the healthcare professional to apply special consideration.


Q: Does Somnopol interact with common birth control methods?

A: Official interaction profiles focus on co-administration with other Central Nervous System (CNS) depressants and specific enzymes. Regulatory guidance indicates there are no major documented interactions or required dose restrictions for common hormonal birth control methods.


Q: Will Somnopol make me feel 'high' or euphoric?

A: Regulatory documents note that the medicine may produce alterations in mood, perception, or euphoria in humans, similar to other sedative-hypnotics. This is a reason it is classified as a controlled substance with potential for abuse.


Q: If I miss a dose of Somnopol, what is the general recommendation?

A: Official guidelines state that if a dose is forgotten by bedtime, the missed dose should be skipped. The official protocol is to take the next dose at the usual time the following night, and not to re-administer a dose during the same night.


Q: Is Somnopol safe to use during pregnancy or while breastfeeding?

A: Official guidance generally does not recommend use during pregnancy due to limited safety information and potential risks to the newborn. For breastfeeding, it passes into breast milk in small amounts, and official information indicates that any use of the medicine while breastfeeding requires a consultation with a healthcare professional.


Q: Is there a generic version of Somnopol available?

A: The active ingredient in Somnopol, Zopiclone, is a well-established substance. It is available as a generic medicine in many regions.


Q: What does the term 'pharmacovigilance' mean regarding Somnopol?

A: Pharmacovigilance is the regulatory process of monitoring the safety of a medicine after it has been approved and released to the public. It involves the continuous collection, assessment, and prevention of adverse effects reported by patients and healthcare professionals.


Q: Why is it necessary to read the Patient Information Leaflet (PIL) for Somnopol?

A: The Patient Information Leaflet (PIL) contains essential regulatory information directly from the manufacturer and approving authority. It details the official instructions for administration, the full list of potential side effects, and conditions where the medicine is strictly prohibited (contraindications).


Q: If I have allergies, can I still take Somnopol?

A: The medicine is strictly contraindicated if there is a known allergy to the drug substance or its ingredients. Regulatory patient information highlights that discussing all allergies, including those to other substances or ingredients, with a doctor is necessary.


Q: Does sun exposure or heat affect Somnopol's safety?

A: Regulatory documents define storage conditions, requiring the medicine to be protected from light, moisture, and excessive heat to maintain stability. There are no official warnings regarding sun exposure or heat exposure during the use of the medicine.


Q: Are there specific times of day that are better for taking Somnopol?

A: Official instructions mandate taking the prescribed dose once per night and administering it immediately before retiring for the night. This timing is essential to ensure the effects coincide with the rest period and limit residual effects the next day.


Q: How is the safety of Somnopol monitored after it is released to the public?

A: The safety of the medicine after release is monitored through the regulatory process of pharmacovigilance. This involves the continuous collection, assessment, and prevention of adverse effects reported by patients and healthcare professionals.


Q: What does it mean if Somnopol is a Schedule IV drug?

A: Somnopol is classified in regulatory systems as a Schedule IV controlled substance. This classification indicates that the medicine has a currently accepted medical use and a lower potential for abuse relative to drugs in Schedule III.


Q: Can I take other supplements to manage side effects from Somnopol?

A: Official interaction profiles caution that some herbal products and supplements, such as St. John's Wort, can alter the drug's effects. Regulatory documents state that informing a doctor and pharmacist of all supplements being taken is necessary to avoid potential interactions, as some products can alter the drug’s effects.


Q: What are the main things I should tell my prescriber before starting Somnopol?

A: Regulatory documents indicate that key information to disclose includes: any known allergies to the medicine, a history of complex sleep behaviors, the use of other CNS depressants or CYP3A4 inhibitors, and pre-existing conditions like severe liver or respiratory insufficiency.


Q: What happens if a user stops taking Somnopol suddenly?

A: Abrupt cessation after prolonged use may result in a transient condition known as rebound insomnia. Official safety documents also note that other potential symptoms that may occur during withdrawal include anxiety, tremors, and palpitations.


Q: Why does the official document list so many potential interactions?

A: The drug’s interaction profile is complex because the medicine is susceptible to two main types of interference. These are pharmacokinetic changes (how the body processes the drug) and pharmacodynamic reinforcement (additive effects with other Central Nervous System depressants).


Q: Does Somnopol have a risk of dependence or tolerance issues?

A: Official safety documents confirm the risk of physical or psychological dependence and tolerance. This risk is noted to increase with higher doses and when the medicine is used for longer than the maximum recommended duration of four weeks.

How should Somnopol be stored and disposed of?

How to Store and Dispose of Somnopol

Official regulatory documents define strict conditions for the storage and disposal of Somnopol (Zopiclone) to ensure its stability and prevent misuse.

Storage and Handling

Somnopol tablets must be kept at room temperature, typically between 15 C and 30 C (59 F and 86 F), and must be protected from light, moisture, and excessive heat. The medication must remain in its original container or blister pack until administration to preserve the product's integrity up to the expiry date. Due to its classification, it is required to keep Somnopol out of the reach and sight of children and to store it securely.

Disposal Instructions

Unused or expired Somnopol must be disposed of according to local regulatory requirements. Medicines must not be thrown away via wastewater or general household waste; individuals should consult a pharmacist for guidance on sanctioned drug take-back programs or proper disposal methods in their area.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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