Lormetazepam

Chemical formula: C₁₆H₁₂Cl₂N₂O₂  Molecular mass: 335.185 g/mol  PubChem compound: 13314

Pregnancy

Benzodiazepines should not be used during pregnancy, especially during the first and last trimesters. Benzodiazepines may cause foetal damage when administered to pregnant women.

If the drug is prescribed to a woman of childbearing potential, she should be warned to contact her physician about stopping the drug if she intends to become, or suspects that she is, pregnant.

There is a possibility that infants born to mothers who take benzodiazepines chronically during the later stages of pregnancy may develop physical dependence. Infants of mothers who ingested benzodiazepines for several weeks or more preceding delivery have been reported to have withdrawal symptoms during the postnatal period. Symptoms such as hypoactivity, hypotonia, hypothermia, respiratory depression, apnoea, feeding problems, and impaired metabolic response to cold stress have been reported in neonates born of mothers who have received benzodiazepines during the late phase of pregnancy or at delivery.

Nursing mothers

Since limited data indicates that a small proportion of parent drug and its conjugate is excreted in breast milk, lormetazepam should not be given to breast-feeding women. Sedation and inability to suckle have occurred in neonates of lactating mothers taking benzodiazepines.

Effects on ability to drive and use machines

Sedation, amnesia, dizziness and impaired muscular function may adversely affect the ability to drive or use machines. If insufficient sleep occurs, the likelihood of impaired alertness may be increased.

This medicine can impair cognitive function and can affect a patient’s ability to drive safely. This class of medicine is in the list of drugs included in regulations under 5a of the Road Traffic Act 1988. When prescribing this medicine, patients should be told:

  • The medicine is likely to affect your ability to drive.
  • Do not drive until you know how the medicine affects you.
  • It is an offence to drive while under the influence of this medicine.
  • However, you would not be committing an offence (called ‘statutory defence’) if:
    • The medicine has been prescribed to treat a medical or dental problem and
    • You have taken it according to the instructions given by the prescriber and in the information provided with the medicine and
    • It was not affecting your ability to drive safely.

Adverse reactions


Adverse reactions, when they occur, are usually observed at the beginning of therapy and generally decrease in severity or disappear with continued use or upon decreasing the dose.

Most frequently reported adverse reactions associated with benzodiazepines include daytime drowsiness, dizziness, muscle weakness and ataxia.

Adverse reactions are listed by frequency: common (>1/100, <1/10); uncommon (>1/1,000, <1/100), rare (>1/10,000, <1/1,000); very rare (<1/10,000).

Blood and lymphatic system disorders

Very rare: Thrombocytopenia, leucopenia, agranulocytosis, pancytopenia

Immune system disorders

Very rare: Hypersensitivity including anaphylaxis/anaphylactoid reactions

Endocrine disorders

Very rare: Inappropriate antidiuretic hormone secretion, hyponatraemia

Psychiatric disorders

Rare: Confusion, depression and unmasking of depression, numbed emotions, disinhibition, euphoria, appetite changes, sleep disturbance, change in libido, decreased orgasm

Unknown: Dependence, Suicidal ideation/attempt

Paradoxical reactions such as restlessness, agitation, irritability, aggressiveness, delusion, rage, insomnia, nightmares, hallucinations, psychoses, sexual arousal, and inappropriate behaviour have been occasionally reported during use.

Nervous system disorders

Very common: Daytime drowsiness, sedation

Common: Dizziness, ataxia

Rare: headache, reduced alertness, dysarthria/slurred speech, transient anterograde amnesia or memory impairment

Very rare: Tremor, extrapyramidal reactions, Coma

Eye disorders

Rare: Visual disturbances (diplopia, blurred vision)

Vascular disorders

Rare: Hypotension

Respiratory thoracic and mediastinal disorders

Rare: Apnoea, worsening of sleep apnoea, worsening of obstructive pulmonary disease.

Respiratory depression

Gastrointestinal disorders

Rare: Nausea, constipation, salivation changes

Hepatobiliary disorders

Rare: Abnormal liver function test values (increases in bilirubin, transaminases, alkaline phosphatase), jaundice

Skin and subcutaneous tissue disorders

Rare: Rash, allergic dermatitis

Musculoskeletal disorders

Common: Muscle weakness

Reproductive system and breast disorders

Rare: Impotence

General disorders

Common: Asthenia, fatigue

Very rare: Hypothermia

Drug withdrawal symptoms

Symptoms reported following discontinuation of benzodiazepines include headaches, muscle pain, anxiety, tension, depression, insomnia, restlessness, confusion, irritability, sweating, and the occurrence of “rebound” phenomena whereby the symptoms that led to treatment with benzodiazepines recur in an enhanced form. These symptoms may be difficult to distinguish from the original symptoms for which the drug was prescribed.

In severe cases the following symptoms may occur: derealisation; depersonalisation; hyperacusis; tinnitus; numbness and tingling of the extremities; hypersensitivity to light, noise, and physical contact; involuntary movements; hyperreflexia, tremor, nausea, vomiting; diarrhoea, abdominal cramps, loss of appetite, agitation, palpitations, tachycardia, panic attacks, vertigo, short-term memory loss, hallucinations/delirium; catatonia; hyperthermia, convulsions. Convulsions may be more common in patients with pre-existing seizure disorders or who are taking other drugs that lower the convulsive threshold such as antidepressants.

Injury, poisoning and procedural complications

Not known: Fall

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Review your medication to ensure that there are no potentially harmful drug interactions or contraindications.

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