Nimetazepam

Nimetazepam

Systematic (IUPAC) name
2-methyl-9-nitro-6-phenyl- 2,5-diazabicyclo[5.4.0]undeca-5,8,10,12-tetraen-3-one
Clinical data
AHFS/Drugs.com	International Drug Names
Pregnancy cat.	X
Legal status	Prohibited (S9) (AU) Schedule IV (US) IV (International)
Routes	Oral
Pharmacokinetic data
Bioavailability	95%
Metabolism	Hepatic
Half-life	14-30 hours
Excretion	Renal
Identifiers
CAS number	2011-67-8 N
ATC code	N05
PubChem	CID 4496
DrugBank	?
ChemSpider	4340 Y
UNII	4532264KW6 Y
KEGG	D01593 Y
ChEMBL	CHEMBL13341 Y
Chemical data
Formula	C16H13N3O3
Mol. mass	295.3
SMILES	eMolecules & PubChem
InChI InChI=1S/C16H13N3O3/c1-18-14-8-7-12(19(21)22)9-13(14)16(17-10-15(18)20)11-5-3-2-4-6-11/h2-9H,10H2,1H3 Y Key:GWUSZQUVEVMBPI-UHFFFAOYSA-N Y
N(what is this?)  (verify)

Nimetazepam (marketed under brand name Erimin) is an intermediate-acting hypnotic drug which is a benzodiazepine derivative. It was first synthesized by a team at Hoffmann-La Roche in 1962^[1]. It possesses hypnotic, anxiolytic, sedative, and skeletal muscle relaxant properties. Nimetazepam is also an anticonvulsant.^[2] It is sold in 5 mg tablets known as Erimin. It is generally prescribed for the treatment of short-term severe insomnia in patients who have difficulty falling asleep or maintaining sleep.

Pharmacokinetics

Taken orally, nimetazepam has very good bioavailability with nearly 100% being absorbed from the gut. It is among the most rapidly absorbed and quickest acting oral benzodiazepines, and hypnotic effects are typically felt within 15-30 minutes after oral ingestion. The blood level decline of the parent drug was biphasic with the short half-life ranging from 0.5-0.7 hours and the terminal half-life from 8–26.5 hours (mean 17.25 hours).^{[citation needed]} It is the N-methylated analogue of nitrazepam (Mogadon, Alodorm), to which it is partially metabolised. Nitrazepam has a long elimination half-life, so effects of repeated dosage tend to be cumulative.

Drug misuse

See also: Benzodiazepine drug misuse

Nimetazepam has a reputation in Malaysia for being particularly subject to abuse especially by persons addicted to amphetamines or opiates.^[3][4]

Legal status

Nimetazepam is currently a Schedule IV drug under the international Convention on Psychotropic Substances of 1971.^[5][6]

In Singapore, nimetazepam is a class C drug under the Misuse of Drugs Act.^[7]

In Hong Kong, nimetazepam is regulated under Schedule 1 of Hong Kong's Chapter 134 Dangerous Drugs Ordinance. Nimetazepam can only be used legally by health professionals and for university research purposes. The substance can be given by pharmacists under a prescription. Anyone who supplies the substance without prescription can be fined $10000 (HKD). The penalty for trafficking or manufacturing the substance is a $5,000,000 (HKD) fine and life imprisonment. Possession of the substance for consumption without license from the Department of Health is illegal with a $1,000,000 (HKD) fine and/or 7 years of jail time.^[8]

Toxicity

In a rat study Nimetazepam showed greater damage to the fetus, as did nitrazepam when compared against other benzodiazepines, all at a dosage of 100mg/kg. Diazepam however showed relatively weak fetal toxicities.^[9] The same fetotoxicity of nitrazepam could not be observed in mice and is likely due to the particular metabolism of the drug in the rat. ^[10]

See also

• Benzodiazepines
• Nitrazepam
• Temazepam
• Flunitrazepam

References

1. ^ US Patent 3109843
2. ^ Fukinaga M; Ishizawa K, Kamei C. (November 1998). "Anticonvulsant properties of 1,4-benzodiazepine derivatives in amygdaloid-kindled seizures and their chemical structure-related anticonvulsant action.". Pharmacology 5 (57): 233–41. doi:10.1159/000028247. PMID 9742288. http://content.karger.com/produktedb/produkte.asp?typ=fulltext&file=pha57233. 
3. ^ DEA Resources, Microgram Journal, Volume 2, Numbers 1-4, January-December 2004
4. ^ "Situational analysis of illicit drug issues and responses in the Asia-Pacific region, Research Paper 12. Australian National Council on Drugs, Canberra.". http://www.ancd.org.au/images/PDF/Researchpapers/rp12_asia_pacific.pdf?phpMyAdmin=rGQ2XkOOsKjMp24r2sFwuVc5ibb. 
5. ^ Annual Estimates Of Requirements Of Narcotic Drugs, Manufacture Of Synthetic Drugs, Opium Production And Cultivation Of The
6. ^ "Green List—List of psychotropic substances under international control" (PDF). International Narcotics Control Board. 23rd edition, August 2003. http://www.incb.org/pdf/e/list/green.pdf. Retrieved 2007-11-25. 
7. ^ "Misuse of drugs act, chapter 185". http://statutes.agc.gov.sg/non_version/cgi-bin/cgi_retrieve.pl?actno=REVED-185. 
8. ^ "Bilingual Laws Information System" (English). The Government of the Hong Kong Special Administrative Region of the People's Republic of China. http://www.legislation.gov.hk/eng/index.htm. 
9. ^ Saito H; Kobayashi H, Takeno S, Sakai T. (1984). "Fetal toxicity of benzodiazepines in rats.". Res Commun Chem Pathol Pharmacol. 46 (3): 437–47. PMID 6151222. 
10. ^ Takeno S; Hirano Y, Kitamura A, Sakai T. (8 1993). "Comparative developmental toxicity and metabolism of nitrazepam in rats and mice". Toxicol Appl Pharmaco. 121 (2): 233–8. doi:10.1006/taap.1993.1150. PMID 8346540.