Lormetazepam: What Is It and What Is It For?

Lormetazepam is a benzodiazepine. As such, it works by depressing the central nervous system. In this case, its properties are used to address moderate or severe insomnia.
Lormetazepam: What Is It and What Is It For?
Samuel Antonio Sánchez Amador

Written and verified by el biólogo Samuel Antonio Sánchez Amador.

Last update: 16 December, 2022

Lormetazepam is a short-acting benzodiazepine. By increasing the activity of gamma-aminobutyric acid (GABA), it has hypnotic, anxiolytic, sedative, anticonvulsant, and muscle relaxant properties. It’s used as a sedative that treats moderate or severe insomnia.

Like any benzodiazepine, this drug has properties capable of producing tolerance, dependence, and withdrawal syndrome. Therefore, its use is only recommended for a period of 2-4 weeks maximum.

What is lormetazepam for?

Lormetazepam is a short-acting benzodiazepine anxiolytic. As we’ve said, it increases the activity of gamma-aminobutyric acid (GABA), a very important neurotransmitter in vertebrate nerve signaling.

As studies indicate, GABA plays an essential role in reducing excitability throughout the nervous system, acting at inhibitory synapses in the brain by binding to specific transmembrane receptors. Quickly stated, lormetazepam binds to benzodiazepine receptors, which in turn increases the effectiveness of GABA.

When this drug binds to benzodiazepine receptors in sufficient quantities, it causes sedative effects. The property of lormetazepam is shared with the rest of benzodiazepines, although there’s scientific proof that its use to treat insomnia is more effective compared to diazepam, for example.

Pharmacokinetics of lormetazepam

This drug is taken by mouth. We can highlight the following points regarding its pharmacokinetics:

  • Absorption: The bioavailability of this drug is approximately 80% of the administered dose. Absorption occurs with a total half-life of 0.5 to 0.9 hours.
  • Distribution: 8.6% of the total plasma level of the drug is in free form. However, this drug binds very effectively to plasma albumin, an essential protein for balance and transport through the bloodstream.
  • Elimination: Lormetazepam is metabolized by glucuronidation. The glucuronide metabolite of lormetazepam doesn’t bind to benzodiazepine receptors, thus losing its functionality, and is almost exclusively excreted in the urine (renal filtration).

As indicated by the Spanish Agency for Medicines and Health Products (CIMA), this drug is prescribed only for the short-term treatment of insomnia. In addition, the general use of benzodiazepines is conceived in the medical field in cases of severe disorders that limit the activity of the patient or subject them to a significant stress situation.

Regional considerations

Lormetazepam was patented in 1961 and began to be used for medical purposes in 1980. In any case, it’s important to note that its sale hasn’t been enabled in the United States and Canada so, in these regions, patients must turn to other analogs or compounds with the same functions. On the other hand, in countries like the United Kingdom, it can be obtained in tablets of 0.5 to 1 milligrams.

Lormetazepam for insomnia.
This drug is prescribed only for insomnia and only for a limited time.

How is it administered?

In some countries, this drug isn’t sold. In others, it’s available in the form of tablets of 0.5 to 1 milligram. It’s sometimes marketed in higher doses, 1 to 2 milligrams per tablet. We’re going to focus on the last variant (1 and 2 milligrams) to treat its dosage, as it seems to be the most widespread.

Lormetazepam CINFA 1 milligram ®

The variant of this brand name reports 1 milligram of lormetazepam per tablet. It’s sold as white, cylindrical, biconvex tablets for oral ingestion, scored on one side, and marked with the designation “Z1” on the back.

In all cases, the duration of treatment should be as short as possible. Even so, several variations can be cited in terms of dosage:

  • Adults: The standard dose in adult patients is one tablet (1 milligram) every 24 hours, 15 to 30 minutes before going to bed. In the case of very severe, disabling, and persistent insomnia, the consumption of 2 tablets a day may be considered.
  • Children and adolescents: Use of this medication isn’t allowed in the pediatric population.
  • Geriatric population: The dose should be reduced to 0.5 milligrams per day. To obtain the appropriate amount, follow the pattern of the groove drawn in the middle of the tablet and divide the tablet into equal parts.

Lormetazepam CINFA 2 mg ®

The presentation of this variant is the same as the previous one, but it’s important to note that each tablet contains 2 milligrams of lormetazepam instead of 1. It’s easy to differentiate one from the other, as it has the marking “Z2” on one of its sides.

The dosage of lormetazepam 2 milligrams is detailed in the following points:

  • Adults: The standard dose is 1/2 tablet a day before going to bed, that is, 1 milligram of lormetazepam.
  • Children and adolescents: Its use in the pediatric population isn’t permitted.
  • Geriatric population: The maximum dose is still 0.5 milligrams per day, so patients must resort to the 1 milligram variant to be able to cut it in half.

The standard duration of treatment is 2 weeks with a maximum of 4 weeks, as dependence symptoms are very mild or don’t appear directly if the drug is used in this period in a controlled manner. Never interrupt treatment on your own if you feel better.

Who shouldn’t take it?

First of all, this drug is completely contraindicated in anyone who’s allergic to lormetazepam, any benzodiazepine, or any of the other excipient components of the pill. Among the latter, we can highlight microcrystalline cellulose (E-460), lactose monohydrate, sodium lauryl sulfate, croscarmellose sodium, and magnesium stearate.

It’s also not recommended in people with myasthenia gravis, severe respiratory failure, and sleep apnea. The drug isn’t contraindicated in patients with closed-angle glaucoma, in those with spinal ataxia or mild kidney failure, but its doses must be adjusted.

Lormetazepam and opioids

The simultaneous use of lormetazepam and opioids can increase drowsiness, decrease respiratory rate, and promote coma and death. This drug cocktail is potentially lethal, so be very careful.

Synergistic effect with alcohol

Alcohol increases the sedative effect of benzodiazepines. Patients must limit the consumption of alcoholic beverages to a minimum if they’re taking the drug. This applies to any other drug that has depressant effects on the central nervous system (CNS).

Pregnancy and breastfeeding

Finally, it’s important to note that this drug shouldn’t be taken during pregnancy. Leaflets indicate that lormetazepam could be related to an increase in fetal deformities in the first trimester of gestation, as it crosses the placenta.

This medicine is also excreted in human milk. Therefore, its use isn’t recommended during lactation, unless the mother needs it and the benefits far outweigh the possible risks.

What are the side effects of lormetazepam?

Like all medicines, lormetazepam can have a variety of side effects. We’ll present them to you based on the percentage of people affected:

  • Very common side effects (more than 1 in 10 patients): The most common symptom in all cases is a headache.
  • Common (up to 1 in 10 patients): Anxiety, altered libido, dizziness, sedation, drowsiness, impaired attention, slurred speech, tachycardia, vomiting, nausea, upper abdominal pain, constipation, dry mouth, urination disorders, asthenia, and hyperhidrosis.
  • Very rare effects (up to 1 in 10,000 patients): Hypersensitivity, syndrome of inappropriate secretion of antidiuretic hormone (SIADH), hyponatremia, hypotension, respiratory failure, allergic dermatitis, apnea, and others.
  • Not known: Angioedema, suicide attempts, acute psychosis, hallucinations, confusional state, delirium, low level of consciousness, tremors.


Long-term use of any benzodiazepine can promote the development of physical and psychological dependence. This is more likely in those who have a history of alcohol and other drug abuse.

To avoid addiction, you should take the following should into account:

  • The taking of lormetazepam will be carried out only under medical prescription. Don’t share this medicine with another person under any circumstances.
  • Never increase the dose prescribed by the doctor. Nor should the treatment be prolonged longer than stipulated.
  • Consider suspending treatment (or not starting it) in people with a history of dependency.
  • Consult your doctor on a regular basis if there’s any doubt regarding the duration of treatment.

What happens if I miss a dose?

If you forget to take lormetazepam before bed and don’t fall asleep, take it when you remember at night. Either way, if you fall asleep, it doesn’t make sense to take it in the morning.

If you miss a dose, take the next one at night as if nothing happened. Never take 2 pills at the same time.

How should I act in case of an overdose?

Benzodiazepine poisoning is a growing problem, as they’re sometimes used as off-label recreational drugs with disastrous consequences. The symptoms of an overdose are the result of central nervous system depression: Confusion, lethargy, ataxia, hypotonia, respiratory depression, coma, and even death.

If you’ve taken too much lormetazepam, call the ER and ask a neighbor or acquaintance to join you while the ambulance arrives. In medical facilities, vomiting is often induced if the patient is conscious, minimizing the risk of aspiration. If the person is unconscious, doctors will use gastric lavage or the administration of activated charcoal.

Lormetazepam overdose.
Benzodiazepines are life-threatening in the case of overdose.

How to store and dispose of this medicine?

This medicine doesn’t require special considerations, beyond taking into account the expiration date on the box. Keep it out of the reach of children and don’t store it above 86 degrees Fahrenheit.

However, special care must be taken when disposing of lormetazepam. Don’t throw it in the trash or down the toilet because, besides the environmental damage that this causes, it’s important to remember that this drug is potentially addictive. Find out about the recycling and pharmacological disposal points in your area.

Final notes on lormetazepam

Lormetazepam is a benzodiazepine. As such, it presents a number of special considerations with respect to other medications.

Its addictive potential and the chances of developing dependence can’t be ignored. Therefore, the treatment should be as short as possible in all cases.

Besides addictive mechanisms, it’s important to note that this drug is part of a treatment. However, it doesn’t solve the problem of insomnia in its entirety. Long-term psychological support is often necessary to discover the underlying causes.

  • Watanabe, Masahito; Maemura, Kentaro; Kanbara, Kiyoto; Tamayama, Takumi; Hayasaki, Hana (2002). «GABA and GABA receptors in the central nervous system and other organs» [GABA y receptores GABA en el sistema nervioso central y otros órganos]. Int Rev Cytol (en inglés) (Osaka, Japón: Academic Press) 213: 1-47.
  • Hentschel, H. D., & Fichte, K. (1981). Lormetazepam in the treatment of sleep disorders in a medical practice; double-blind test on 100 patients (author’s transl). Deutsche medizinische Wochenschrift (1946), 106(22), 711-714.
  • Ficha técnica CIMA. Recogido a 10 de julio en https://cima.aemps.es/cima/pdfs/es/ft/68371/68371_ft.pdf
  • Lormetazepam CINFA 1 mg. Recogido a 10 de julio en https://cima.aemps.es/cima/dochtml/p/68371/P_68371.html

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