No reaction
No reactionWARNINGMIXING 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.
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Nimetazepam
1-Methylnitrazepam
Erimin, Erimin-5, Happy 5, Lavol, Ro 5-3453Open in Piru
Nimetazepam is an intermediate-acting benzodiazepine depressant with strong sedative, sleep-inducing and anxiety-reducing effects. It was first synthesized by a team at Hoffmann-La Roche in 1964. It also has muscle-relaxant properties1 and particularly potent anticonvulsant effects, and has been prescribed for severe insomnia. Its use can lead to addiction.2 In Malaysia, many tablets sold as nimetazepam on the illicit market are counterfeit,3 with other benzodiazepines, including diazepam and nitrazepam, sometimes sold in its place.4
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Threshold~2.5 mg
Light2.5-5 mg
Moderate5-10 mg
Strong10-20 mg
Heavy20+ mg
Duration
Onset15-30 minutes
After Effects12-24 hours
Total5-8 hours
Subjective Effects
Subjective Effects not written up yet
Pharmacology
Pharmacokinetics
Nimetazepam is rapidly absorbed after oral administration, with nearly complete absorption from the gut and very good bioavailability. Blood concentrations of the parent drug decline in two phases, with an initial half-life of 0.5-0.7 hours and a terminal elimination half-life of 8-26.5 hours (mean 17.25 hours). It is partially converted to a metabolite with a long elimination half-life, which contributes to accumulation with repeated administration.
Dangerous
Highest riskThese combinations are considered extremely harmful and should always be avoided. Reactions to these drugs taken in combination are highly unpredictable and have a potential to cause death.
Unsafe
AvoidThere is considerable risk of physical harm when taking these combinations, they should be avoided where possible.
Caution
Use cautionThese combinations are not usually physically harmful, but may produce undesirable effects, such as physical discomfort or overstimulation. Extreme use may cause physical health issues. Synergistic effects may be unpredictable. Care should be taken when choosing to use this combination.
Tolerance
Tolerance not written up yet
Harm Potential
Addiction & Dependence
Psychological
Nimetazepam has habit-forming properties and substantial misuse and addiction among medical and non-medical users. High binding affinity, high potency, rapid onset, and short-to-intermediate action contribute to its abuse potential.
Physical
Nimetazepam can cause physical dependence and a withdrawal syndrome, which contribute to its addictive potential.
Toxicity
In rats given 100 mg/kg, nimetazepam caused greater fetal damage than other benzodiazepines in the comparison; nitrazepam showed a similar comparative finding.5
High-dose nimetazepam exposure in rats produced slight liver enlargement at weeks 4 and 12, without histopathological changes.
High-dose nimetazepam exposure in rats produced slight adrenal enlargement at weeks 4 and 12, without histopathological changes.
High-dose nimetazepam exposure in rats produced testicular atrophy at weeks 4 and 12, with degeneration of the seminiferous epithelium.
High-dose nimetazepam exposure in rats produced ovarian atrophy at weeks 4 and 12, without histopathological changes.
History & Culture
Nimetazepam was first synthesized in 1964 by a team at Hoffmann-La Roche. The Japanese corporation Sumitomo manufactured and marketed it under the brand name Erimin. During the 1980s and 1990s, it was widely prescribed for severe insomnia in Japan, Malaysia, Brunei, the Philippines, Thailand,…
Legality
International
Controlled internationally under the UN Convention on Psychotropic Substances 1971.
By Country
Illegal1
Hong KongIllegalDangerous Drugs Ordinance (Cap. 134), First Schedule, Part I7
Nimetazepam is listed by exact name in Part I of the First Schedule to the Dangerous Drugs Ordinance (Cap. 134) as a dangerous drug. The Ordinance prohibits trafficking and unauthorized supply, unlicensed manufacture, and unauthorized possession or consumption; trafficking includes import and export. Licensing and medical-authority exceptions apply to authorized handling.
Controlled / restricted1
United Statescategorized Schedule IV FDA and DEAPrescription1
SingaporePrescription onlyMisuse of Drugs Act 1973, First Schedule, Part 3; Misuse of Drugs Regulations, regulations 6 to 12 and Second Schedule8910
Nimetazepam is listed by name as a Class C drug in Part 3 of the First Schedule to the Misuse of Drugs Act 1973; the listing also covers its stereoisomeric forms, salts, and preparations or products containing it. The Misuse of Drugs Regulations list nimetazepam in the Second Schedule and permit its administration by a medical practitioner, dentist, or collaborative prescribing practitioner, or under such a practitioner's direction. A patient may possess it for medical, dental, or veterinary administration in accordance with a practitioner's directions, and prescriptions are subject to controlled-drug form, validity, authentication, dispensing, and retention requirements.
Article Status
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