WARNINGMIXING OR WITHDRAWAL CAN BE DANGEROUS
Ordinary doses in combination with other depressants can fatally stop breathing. After prolonged dependency, stopping suddenly can also cause seizures or delirium; seek medical help.
Citation noticeOur citation system is being overhauled
References and citation markers may currently be incomplete, mismatched, or incorrect. This system is being rebuilt and reviewed before the full site launch.
Lormetazepam
Lormetazepam is a central nervous system depressant1 in the 1,4-benzodiazepine class1 and an analogue of temazepam.2 It produces sedative, sleep-inducing, and anxiety-reducing effects3 and is used for the short-term treatment of insomnia.3 Its action is short to intermediate in duration.4 It first became available in 1980.4 Like other benzodiazepines, it can be habit-forming.5
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Duration
Subjective Effects
Pharmacology
Pharmacodynamics
Lormetazepam positively modulates GABA-A receptors by binding to the benzodiazepine site between their α and γ subunits.6 It acts at receptors containing γ2 together with α1, α2, α3, or α5 subunits,6 facilitating chloride channel opening and reducing neuronal excitability.6 It appears to favor the ω1 benzodiazepine binding site,7 which is associated with its sedative action.
Pharmacokinetics
Lormetazepam is orally available, with reported bioavailability of 80%.9 It undergoes glucuronide conjugation to form an inactive metabolite.10 Its terminal elimination half-life is reported as 11 hours,3 with an approximate range of 10-12 hours also described.
Interactions
An unlisted combination is an unknown one, not a safe one. Check a dedicated combination chart before mixing.
Tolerance
Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.
Harm Potential
Addiction & Dependence
Psychological
Lormetazepam is habit-forming and can produce psychological dependence.11 Dependence risk is described as very low with use limited to 2–4 weeks, but a history of addiction, particularly to sedative hypnotics, increases susceptibility.
Physical
Lormetazepam can cause physical dependence associated with altered sensitivity of the GABA–benzodiazepine receptor complex, with withdrawal following dose reduction or discontinuation and sometimes occurring at an unchanged dose with subsequent dose escalation. Dependence and withdrawal risks are described as very low with use limited to 2–4 weeks, although rebound insomnia can occur after seven days and rebound REM sleep has been reported after chronic use. Withdrawal usually resolves within 4–8 weeks, but symptoms persist for months in approximately 10–15% of individuals and rarely for years; gradual tapering after substitution with an equivalent diazepam dose is recommended.
Toxicity
Lormetazepam overdose can cause respiratory depression that progresses to death; manifestations range from drowsiness to coma and may include ataxia, hypotension, and reduced muscle tone.
LD50 Data
| Species | Route | Value |
|---|---|---|
| Mouse | Intraperitoneal | 780 mg/kg |
| Mouse | Oral | 1790 mg/kg |
| Mouse | Subcutaneous | 10000 mg/kg |
| Rat | Intraperitoneal | 6250 mg/kg |
| Rat | Oral | 10000 mg/kg |
| Rat | Intraperitoneal | 10000 mg/kg |
Lormetazepam can impair memory, cognition, psychomotor performance, and driving ability; residual impairment after nighttime administration can persist into the following day and increase the risk of falls and hip fractures.
Lormetazepam overdose can suppress respiration and may be fatal.
Jaundice is a reported adverse effect of lormetazepam.3
Blood disorders are reported adverse effects of lormetazepam.3
Lormetazepam can cause urinary retention or urinary incontinence.
Lormetazepam can cause gastrointestinal disturbances and changes in salivation.3
Skin reactions are reported adverse effects of lormetazepam.3
Visual disturbances are reported adverse effects of lormetazepam.3
Lormetazepam can cause muscle weakness12, and overdose can cause reduced muscle tone.
History & Culture
Lormetazepam first became available in 1980.4
Legality
International
Lormetazepam is approved.
By Country
NetherlandsIllegal
United KingdomPrescription onlyReferences
Citations
Article Status
Step 1 · Automated synthesisAn autonomous workflow built by Josie Kins compiled this article's foundation from information published across the web.
- Step 2 · First-pass reviewPending
Not yet reviewed: this article is pending editorial review by Lyrea.
- Step 3 · Citation reviewPending
No one has reviewed this article's citations yet. That second pass checks each claim against the source it cites.
Suggest an edit
Spotted a mistake, an outdated claim, or something missing from the Lormetazepam article? Send the editors a private note. Feedback lands in a moderation queue and is never shown on the site.
Wish to give generalised feedback? You can do so here.
