Heminevrin: Uses, Dosage & Side Effects
A sedative-hypnotic capsule used for alcohol withdrawal management and elderly care
Quick Facts
Key Takeaways
- Heminevrin (clomethiazole) is a sedative with hypnotic and anticonvulsant properties, used primarily for alcohol withdrawal and geriatric agitation.
- Treatment should be kept as short as possible (typically 5–9 days for alcohol withdrawal) due to the risk of dependence and tolerance.
- Alcohol must not be consumed during treatment – the combination can cause life-threatening respiratory depression.
- Common side effects include nasal and eye irritation, while serious but rare reactions include severe allergic responses and respiratory depression.
- Not suitable for patients with significant respiratory impairment or for children and adolescents under 18 years of age.
What Is Heminevrin and What Is It Used For?
Heminevrin is the brand name for clomethiazole edisylate, a thiazole-derivative compound that has been used in clinical medicine since the 1960s. The drug works by enhancing the action of gamma-aminobutyric acid (GABA), the brain's primary inhibitory neurotransmitter, leading to a reduction in neuronal excitability throughout the central nervous system. This mechanism of action gives Heminevrin its three principal pharmacological effects: sedation, sleep induction (hypnosis), and seizure prevention (anticonvulsion).
The primary clinical applications of Heminevrin are twofold. First, it is widely used in the acute management of alcohol withdrawal syndrome, where it helps control the dangerous neurological hyperexcitability that occurs when a person with alcohol dependence abruptly stops drinking. During alcohol withdrawal, the brain becomes overexcited because the chronic depressant effect of alcohol is suddenly removed, which can trigger tremor, hallucinations, agitation, and life-threatening seizures. Heminevrin helps stabilize this state by restoring inhibitory balance through its GABAergic mechanism.
Second, Heminevrin is used in geriatric care for the short-term management of confusional states, restlessness, and sleep disturbances in elderly patients. Older adults may experience episodes of acute confusion (delirium) associated with underlying medical conditions, hospitalisation, or dementia, and Heminevrin can provide symptomatic relief in these situations. However, its use in this population requires careful dose adjustment due to the increased sensitivity of elderly patients to sedative effects and the potential for adverse cardiovascular effects such as hypotension and tachycardia.
Heminevrin is available as soft capsules containing 300 mg of clomethiazole edisylate (equivalent to 192 mg of the free base clomethiazole). It is rapidly absorbed after oral administration, with peak plasma concentrations typically reached within 30 to 90 minutes. The drug undergoes extensive first-pass metabolism in the liver, and its elimination half-life is approximately 4 to 6 hours in healthy adults, though this may be substantially prolonged in patients with hepatic impairment or advanced age.
Clomethiazole, the active ingredient in Heminevrin, may also be approved for treating conditions not listed in this article. Always follow the instructions of your prescribing physician and consult your healthcare provider or pharmacist if you have additional questions about your treatment.
What Should You Know Before Taking Heminevrin?
Contraindications
There are specific situations where Heminevrin must not be used. Understanding these contraindications is essential for patient safety. You should not take Heminevrin if:
- Allergy to clomethiazole edisylate – If you have a known hypersensitivity to clomethiazole or any of the other ingredients in the capsule (including medium-chain triglycerides, gelatin, glycerol, mannitol, sorbitol, hydrogenated partially hydrolysed starch, titanium dioxide, and brown iron oxide), do not take this medication.
- Severe respiratory impairment – Patients with significantly compromised lung function should not use Heminevrin, as the drug can further depress respiratory drive and worsen breathing difficulties.
Warnings and Precautions
Speak with your doctor or pharmacist before taking Heminevrin if any of the following conditions apply to you. These situations require special caution and may necessitate dose adjustments, additional monitoring, or the consideration of alternative treatments.
- Sleep apnea syndrome – Heminevrin can worsen episodes of breathing cessation during sleep, making this condition particularly dangerous in combination with the drug.
- Impaired lung function – Even if not classified as severe, any reduction in respiratory capacity requires careful assessment before starting treatment.
- Liver disease or hepatic impairment – Because Heminevrin is extensively metabolised in the liver, reduced hepatic function can lead to significantly higher drug levels, prolonged effects, and increased risk of toxicity. This is particularly relevant for patients with alcohol-related liver disease.
- Kidney impairment – Reduced renal function may affect drug clearance and require dose adjustments.
- Cardiovascular risk factors – Patients at risk of cerebrovascular or cardiovascular complications should use Heminevrin with caution due to the potential for hypotension (low blood pressure) and tachycardia (rapid heart rate). This concern is especially important in elderly patients.
Simultaneous use of Heminevrin and alcohol must be avoided. The combination significantly increases the risk of severe central nervous system depression, which can result in dangerously slowed breathing, loss of consciousness, and death. Although Heminevrin is used to treat symptoms of alcohol withdrawal, patients must have stopped drinking before treatment begins. The same risk applies when Heminevrin is combined with other CNS depressant medications.
Heminevrin can be habit-forming. With prolonged use, physical and psychological dependence may develop, and the body may develop tolerance, meaning higher doses are needed to achieve the same effect. A period of rebound insomnia (difficulty sleeping) may occur when treatment is stopped. For these reasons, Heminevrin should only be used for the shortest possible duration under close medical supervision.
Pregnancy and Breastfeeding
If you are pregnant, breastfeeding, think you may be pregnant, or are planning to become pregnant, consult your doctor or pharmacist before using Heminevrin. The decision to use this medication during pregnancy or breastfeeding should be made carefully, weighing the potential benefits against the risks.
Pregnancy: Clomethiazole should not be used during pregnancy unless there are compelling clinical reasons and the expected benefit clearly outweighs the potential risk to the foetus. Clomethiazole crosses the placental barrier and may cause neonatal sedation and respiratory depression. Animal studies and limited human data suggest potential risks, and the drug should be avoided particularly during the first trimester and near the time of delivery. If use during late pregnancy is unavoidable, the newborn should be closely monitored for signs of sedation, poor feeding, and respiratory difficulties.
Breastfeeding: Clomethiazole is excreted into breast milk, although it is considered unlikely to affect the nursing infant at standard therapeutic doses. Nevertheless, caution is advised. Discuss the potential risks with your doctor before using Heminevrin during breastfeeding. If the drug is deemed necessary, monitor the breastfed infant for signs of excessive sedation, poor feeding, or unusual drowsiness.
Children and Adolescents
Heminevrin soft capsules are not recommended for use in children and adolescents under 18 years of age. The safety and efficacy of clomethiazole in this age group have not been established, and there is insufficient evidence to support its use in paediatric patients. Alternative treatments should be considered for younger patients experiencing symptoms that might otherwise warrant sedative-hypnotic therapy.
Driving and Operating Machinery
Heminevrin capsules can significantly impair your reaction time, concentration, and motor coordination. You should avoid driving motor vehicles or operating heavy machinery while taking this medication. When Heminevrin is used as a sleep aid, next-morning residual effects (sometimes called “hangover effects”) may persist, although this is uncommon. The risk of impairment increases significantly if alcohol has also been consumed. You are personally responsible for assessing whether you are fit to drive or perform work that requires alertness.
How Does Heminevrin Interact with Other Drugs?
Drug interactions can significantly alter the effectiveness and safety profile of Heminevrin. Clomethiazole is metabolised primarily by cytochrome P450 enzymes in the liver, and substances that inhibit or induce these enzymes can increase or decrease clomethiazole plasma concentrations, respectively. Additionally, pharmacodynamic interactions with other central nervous system depressants are of particular clinical concern.
The most important drug interactions with Heminevrin are summarised in the table below. This list is not exhaustive, and you should always inform your prescribing physician and pharmacist about all medications, supplements, and herbal products you are currently taking or have recently taken.
| Interacting Drug | Drug Class | Type of Interaction | Clinical Significance |
|---|---|---|---|
| Cimetidine | H2-receptor antagonist (peptic ulcer medication) | Inhibits clomethiazole metabolism, raising plasma levels | Major – Increased risk of excessive sedation and toxicity |
| Carbamazepine | Anticonvulsant / mood stabiliser | Induces clomethiazole metabolism, lowering plasma levels | Major – Reduced therapeutic effectiveness of Heminevrin |
| Propranolol | Beta-blocker (antihypertensive) | Mutual pharmacokinetic interaction; may increase clomethiazole levels | Moderate – Monitor for enhanced sedation and cardiovascular effects |
| Chlorzoxazone | Muscle relaxant | Mutual CYP2E1-mediated interaction | Moderate – Potential for altered drug levels of both medications |
| Alcohol (ethanol) | CNS depressant | Additive/synergistic CNS and respiratory depression | Contraindicated – Risk of fatal respiratory depression |
| Other CNS depressants (benzodiazepines, opioids, antipsychotics) | Various sedative/hypnotic classes | Additive CNS depression | Major – Increased sedation, respiratory depression, and fall risk |
Major Interactions
Cimetidine is one of the most clinically significant interactions with Heminevrin. Cimetidine inhibits the hepatic cytochrome P450 enzyme system, particularly CYP2E1 and CYP3A4, which are involved in the metabolism of clomethiazole. When these enzymes are inhibited, clomethiazole is broken down more slowly, resulting in significantly higher plasma concentrations. This can lead to excessive sedation, prolonged drug effects, and increased risk of adverse events including respiratory depression. If cimetidine is being used for peptic ulcer disease, alternative acid-suppressive therapy (such as proton pump inhibitors) should be considered during Heminevrin treatment.
Carbamazepine is a potent inducer of hepatic enzymes, particularly CYP3A4. Chronic carbamazepine use can increase the rate of clomethiazole metabolism, leading to lower than expected plasma levels and potentially reduced therapeutic efficacy. This is particularly important in patients being treated for alcohol withdrawal, where inadequate clomethiazole levels could result in breakthrough seizures. Dose adjustments may be necessary, and close clinical monitoring is essential.
Alcohol represents the most dangerous interaction with Heminevrin. Despite the drug being used for alcohol withdrawal treatment, the concurrent ingestion of alcohol with clomethiazole produces severe, synergistic central nervous system depression. This combination has been associated with fatal outcomes. Patients must be confirmed to have stopped drinking before Heminevrin therapy is initiated, and strict abstinence from alcohol must be maintained throughout the treatment period.
Minor Interactions
Propranolol may interact with Heminevrin through pharmacokinetic mechanisms. Both drugs undergo hepatic metabolism, and propranolol has been shown to reduce hepatic blood flow, which can increase the bioavailability of high-clearance drugs like clomethiazole. Patients receiving both medications should be monitored for enhanced sedative effects and changes in blood pressure or heart rate. Dose adjustments of either medication may be needed.
Chlorzoxazone, a centrally acting muscle relaxant, shares metabolic pathways with clomethiazole (particularly CYP2E1). Co-administration may alter the plasma levels of both drugs. While the clinical significance of this interaction is considered moderate, physicians should be aware of the potential for unexpected changes in drug effects when these medications are used together.
What Is the Correct Dosage of Heminevrin?
Heminevrin dosage must always be individually determined by the prescribing physician, who will consider the patient's age, weight, underlying conditions, hepatic and renal function, and the specific indication for treatment. The following dosage information is provided as general guidance and should not be used as a substitute for your doctor's instructions.
The soft capsules must be swallowed whole with a sufficient amount of water. Do not chew, crush, or break the capsules. Alternative administration routes (such as rectal use) are not recommended for the capsule formulation.
Adults – Alcohol Withdrawal
For acute alcohol withdrawal, treatment is typically initiated with higher doses that are progressively reduced over 5 to 9 days (a tapering regimen). Doses are usually given in divided doses throughout the day, with particular attention to nighttime dosing to manage insomnia and nocturnal agitation. The exact dosing schedule is determined by the severity of withdrawal symptoms and the patient's clinical response, using standardised assessment scales. Treatment should be conducted under medical supervision, typically in an inpatient setting.
Elderly Patients – Confusion, Restlessness, and Sleep Disturbances
In elderly patients, dosage should be kept as low as possible and treatment duration minimised. Older adults are more sensitive to the sedative and cardiovascular effects of clomethiazole. For sleep disturbances, a single dose at bedtime is typically used. The prescribing physician will carefully balance the need for symptom relief against the risks of excessive sedation, hypotension, tachycardia, and falls. Non-pharmacological interventions should be tried first or used alongside medication.
Children and Adolescents
Heminevrin is not recommended for patients under 18 years of age. No paediatric dosing guidelines have been established.
Patients with Hepatic Impairment
Patients with liver disease, including alcohol-related liver damage, may have significantly reduced capacity to metabolise clomethiazole. This can lead to markedly higher and more prolonged drug levels, increasing the risk of excessive sedation and respiratory depression. Dose reduction and careful monitoring are essential in this population. The prescribing physician will take hepatic function into account when determining the appropriate dose.
Missed Dose
If you forget to take a dose of Heminevrin, take it as soon as you remember. However, if it is almost time for your next scheduled dose, skip the missed dose entirely. Do not take a double dose (two doses at the same time) to make up for a missed one. If you are unsure about what to do, contact your doctor or pharmacist for advice.
Overdose
If you or someone else has taken too much Heminevrin, or if a child has accidentally ingested the medication, seek emergency medical attention immediately by contacting your local emergency services or poison control centre. Clomethiazole overdose can cause profound sedation, severe respiratory depression, dangerously low blood pressure, and coma. The risk of fatal outcome is substantially increased when Heminevrin is taken in combination with other central nervous system depressants, particularly alcohol. There is no specific antidote for clomethiazole overdose; treatment is primarily supportive, focusing on maintaining airway patency, adequate ventilation, and cardiovascular support in an intensive care setting.
Stopping Treatment
When it is time to stop Heminevrin, your doctor will usually recommend a gradual dose reduction rather than abrupt discontinuation. Stopping suddenly after regular use may lead to rebound effects, including worsening insomnia, anxiety, and in rare cases, withdrawal symptoms. For alcohol withdrawal protocols, the tapering schedule is built into the treatment regimen. Always follow your doctor's instructions regarding when and how to stop taking Heminevrin.
What Are the Side Effects of Heminevrin?
Like all medicines, Heminevrin can cause side effects, although not everyone who takes it will experience them. Side effects are classified below by how frequently they occur, based on reports from clinical use and post-marketing surveillance. If you experience any side effects that are severe, persistent, or concerning, contact your doctor or pharmacist. If you develop signs of a severe allergic reaction, stop taking Heminevrin and seek immediate medical attention.
Sudden wheezing, swelling of the lips, tongue, throat, or body, skin rash, feeling faint, or difficulty swallowing – these may be signs of a severe allergic reaction (anaphylaxis). This is a rare side effect, occurring in fewer than 1 in 1,000 users.
Common
- Nasal and eye irritation (tingling or burning sensation) – often diminishes or resolves with continued treatment
Uncommon
- Gastrointestinal disturbances (heartburn, stomach pain, nausea, diarrhoea, vomiting)
- Itching (pruritus)
- Hives (urticaria)
- Runny nose and nasal congestion (rhinitis)
- Increased mucus production in the throat and airways
- Elevated liver enzyme levels (reversible upon discontinuation)
- Headache
Rare
- Severe allergic reaction (anaphylaxis)
- Blistering skin rash (bullous eruption)
- Low blood pressure (hypotension)
- Liver damage including jaundice (yellowing of the skin and eyes)
Not Known
- Tingling or prickling sensations (paraesthesia)
- Severe anaphylactic shock
- Respiratory depression (impaired breathing)
- Cardiac arrest
- Facial swelling (oedema)
It is important to understand the context of these side effects. The common nasal and eye irritation is thought to be caused by a metabolite of clomethiazole and is generally self-limiting. The gastrointestinal side effects are typically mild and manageable. The more serious adverse events, such as respiratory depression and cardiac arrest, are predominantly associated with overdose situations or concurrent use with other CNS depressants (particularly alcohol) rather than normal therapeutic use.
Elevated liver enzyme levels (transaminases) are typically asymptomatic and reversible upon discontinuation of the drug. However, frank liver damage with jaundice, although rare, has been reported and requires immediate medical evaluation. Patients with pre-existing liver disease, particularly alcohol-related hepatic damage, may be at greater risk.
If you experience any side effects not listed above, or if any side effect becomes serious or bothersome, inform your doctor or pharmacist. Reporting suspected adverse reactions after the medicine has been authorised is important, as it allows for continuous monitoring of the benefit-risk balance of the medication.
How Should You Store Heminevrin?
Proper storage of Heminevrin is important to maintain the quality and effectiveness of the medication. The soft capsules should be stored at a temperature not exceeding 25°C (77°F). Protect the capsules from excessive heat and moisture. Keep the medicine in its original glass container to provide optimal protection.
Store Heminevrin out of the sight and reach of children at all times. Given the sedative nature of this medication, accidental ingestion by a child poses a serious medical risk and should be treated as a medical emergency.
Do not use Heminevrin after the expiry date printed on the packaging (marked as “EXP”). The expiry date refers to the last day of the stated month. Once the medicine has passed its expiry date, return it to a pharmacy for safe disposal.
Do not dispose of medicines via household waste or down the drain. Ask your pharmacist about how to properly dispose of medicines that are no longer needed. These measures help to protect the environment and prevent accidental exposure.
What Does Heminevrin Contain?
Understanding the complete composition of Heminevrin can help identify potential allergens or ingredients that may cause intolerance in some patients.
Active substance: Clomethiazole 192 mg, corresponding to clomethiazole edisylate 300 mg per soft capsule. Clomethiazole edisylate is the salt form of the active compound that provides improved stability and bioavailability compared to the free base.
Other ingredients (excipients):
- Medium-chain triglycerides (MCT oil) – serves as the fill medium for the soft capsule
- Gelatin – forms the capsule shell
- Glycerol 85% – plasticiser for the capsule shell
- Mannitol – bulking agent
- Sorbitol – sweetening agent (each capsule contains approximately 7 mg of sorbitol; if you have a known intolerance to certain sugars, consult your doctor before taking this medicine)
- Hydrogenated partially hydrolysed starch – capsule shell component
- Titanium dioxide (E171) – colouring agent
- Brown iron oxide (E172) – colouring agent (gives the capsule its characteristic greyish-brown appearance)
Appearance: Heminevrin capsules are soft, greyish-brown in colour. They are supplied in glass jars containing either 25 capsules or 300 capsules (3 jars of 100). Not all pack sizes may be marketed in all countries.
Marketing authorisation holder and manufacturer: CHEPLAPHARM Arzneimittel GmbH, Ziegelhof 24, 17489 Greifswald, Germany. For local product enquiries in your country, contact your national distributor or regulatory body for further information.
Frequently Asked Questions
Heminevrin (clomethiazole) is primarily used for two clinical purposes: the management of alcohol withdrawal symptoms (including agitation, tremor, hallucinations, and seizures) and the short-term treatment of confusion, restlessness, and sleep disturbances in elderly patients. The drug has sedative, hypnotic, and anticonvulsant properties that make it effective for these conditions. It is a prescription medication that should only be used under direct medical supervision, typically in a hospital or clinical setting for alcohol withdrawal, and with careful monitoring in geriatric care.
Yes, Heminevrin can be habit-forming with prolonged use. Physical and psychological dependence may develop, and tolerance (reduced effectiveness at the same dose) can occur over time. This is why treatment should be limited to the shortest possible duration – typically no more than 5 to 9 days for alcohol withdrawal, and only short-term use for geriatric indications. When stopping treatment, your doctor will typically recommend a gradual dose reduction to avoid rebound insomnia and withdrawal symptoms. Never take Heminevrin for longer than prescribed or in higher doses than recommended.
No, you must never drink alcohol while taking Heminevrin. This is an absolute contraindication. The combination of clomethiazole and alcohol produces severe, synergistic central nervous system and respiratory depression that can be fatal. Even small amounts of alcohol can dramatically amplify the sedative effects of Heminevrin, leading to excessive drowsiness, dangerously slow breathing, loss of consciousness, and death. Although Heminevrin is used to treat the symptoms of alcohol withdrawal, patients must have completely stopped drinking alcohol before treatment is started.
Heminevrin is rapidly absorbed after oral administration. Peak blood levels are typically reached within 30 to 90 minutes of taking a capsule, and the sedative effects usually become apparent within this timeframe. The onset of action may be faster in patients with impaired liver function (such as those with alcohol-related liver disease) because more of the drug bypasses first-pass metabolism, resulting in higher initial blood levels. The duration of effect is approximately 4 to 6 hours in most patients, although this can be prolonged in elderly patients and those with hepatic impairment.
Heminevrin can be used in elderly patients, but it requires particular caution and careful dose adjustment. Older adults are more sensitive to the sedative effects of clomethiazole, and they are at increased risk of adverse cardiovascular effects, particularly low blood pressure (hypotension) and rapid heart rate (tachycardia). These effects can increase the risk of falls and related injuries such as hip fractures. The dosage should be kept as low as possible, and non-pharmacological interventions for managing confusion and sleep disturbances should be considered as first-line treatments before resorting to medication.
Both Heminevrin (clomethiazole) and benzodiazepines (such as diazepam, chlordiazepoxide, or lorazepam) are used to manage alcohol withdrawal, but they differ in several important ways. Clomethiazole acts on GABA receptors through a distinct mechanism from benzodiazepines and has a shorter half-life (approximately 4–6 hours vs. much longer for many benzodiazepines). In many European countries, clomethiazole has been the traditional first-line treatment for alcohol withdrawal, while benzodiazepines are more commonly used in North America and much of the rest of the world. Both classes carry risks of dependence and respiratory depression. The choice between them depends on local clinical guidelines, the specific clinical situation, available monitoring capabilities, and prescriber expertise.
References
- European Medicines Agency (EMA). Summary of Product Characteristics: Clomethiazole (Heminevrin). Available at: www.ema.europa.eu. Accessed December 2025.
- British National Formulary (BNF). Clomethiazole – Drug Monograph. NICE Evidence Services. Available at: bnf.nice.org.uk. Accessed December 2025.
- National Institute for Health and Care Excellence (NICE). Clinical guideline [CG115]: Alcohol-use disorders: diagnosis and management of physical complications. Available at: www.nice.org.uk. Updated 2023.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List. Geneva: WHO; 2023.
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- CHEPLAPHARM Arzneimittel GmbH. Heminevrin (clomethiazole edisylate) – Patient Information Leaflet. Greifswald, Germany. Revised January 2024.
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