Metatop (Lormetazepam)

Lormetazepam is a benzodiazepine hypnotic that acts on the central nervous system to facilitate sleep.

• Insomnia (sleep onset): helps patients fall asleep more quickly.
• Insomnia (sleep maintenance): reduces nighttime awakenings and improves sleep continuity.
• Insomnia (short‑term use): provides temporary relief of sleep disturbance for up to four weeks.

• Lormetazepam binds to the benzodiazepine site on the GABA‑A receptor complex, acting as a positive allosteric modulator. This enhances the inhibitory effect of the neurotransmitter GABA, increasing chloride ion influx, hyperpolarising neuronal membranes and producing sedative, anxiolytic and hypnotic effects that facilitate sleep initiation and maintenance.

Lormetazepam may cause a range of adverse reactions, from mild to severe.

Common Side Effects

• Drowsiness: feeling unusually sleepy during the day.
• Dizziness: light‑headed sensation, especially when standing quickly.
• Fatigue: reduced energy and motivation.
• Memory impairment: difficulty recalling recent events.
• Ataxia: uncoordinated movements or gait instability.
• Headache: mild to moderate head pain.

Serious or Rare Side Effects

• Respiratory depression: slowed or shallow breathing, especially with other depressants.
• Dependence or withdrawal syndrome: cravings, anxiety or seizures on abrupt cessation.
• Paradoxical reactions: agitation, aggression or increased anxiety.
• Severe allergic reactions: rash, swelling, or anaphylaxis.
• Depression or suicidal ideation: mood changes requiring urgent medical attention.
• Hepatic dysfunction: abnormal liver enzymes or jaundice.

Before prescribing Lormetazepam, clinicians should consider several safety factors.

• Use in elderly: increased risk of falls and cognitive impairment.
• Abrupt discontinuation: may precipitate withdrawal symptoms; tapering is recommended.
• Hepatic impairment: reduced metabolism may increase drug exposure.
• Concomitant alcohol: additive central nervous system depression.
• Pregnancy: limited safety data; avoid unless benefit outweighs risk.
• Store at room temperature: keep in the original pack, protect from moisture.

Lormetazepam can interact with other medicines, altering its efficacy or safety.

Major Interactions (Avoid)

• Opioids or other CNS depressants: risk of profound sedation or respiratory depression.
• Alcohol: additive sedative effect, increasing impairment.
• Ketoconazole or other strong CYP3A4 inhibitors: may raise plasma concentrations.

Moderate Interactions (Monitor Closely)

• Erythromycin or other moderate CYP3A4 inhibitors: may modestly increase levels.
• Rifampicin or other CYP3A4 inducers: may reduce therapeutic effect.
• Selective serotonin reuptake inhibitors (SSRIs): can enhance sedation.