Prazepam

Clinical data
Other names	9-chloro-2-(cyclopropylmethyl)-6-phenyl-2,5-diazabicyclo[5.4.0]undeca-5,8,10,12-tetraen- 3-one
AHFS/Drugs.com	Micromedex Detailed Consumer Information
MedlinePlus	a601036
Routes of administration	Oral
ATC code	N05BA11 (WHO)
Legal status
Legal status	BR: Class B1 (Psychoactive drugs)[1] CA: Schedule IV DE: Prescription only (Anlage III for higher doses) US: Schedule IV
Pharmacokinetic data
Metabolism	Hepatic
Elimination half-life	36–200 hours
Excretion	Renal
Identifiers
IUPAC name 7-Chloro-1-(cyclopropylmethyl)-5-phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-one
CAS Number	2955-38-6 Y
PubChem CID	4890
IUPHAR/BPS	7275
DrugBank	DB01588 Y
ChemSpider	4721 Y
UNII	Q30VCC064M
KEGG	D00470 Y
ChEMBL	ChEMBL969 Y
CompTox Dashboard (EPA)	DTXSID4021181
ECHA InfoCard	100.019.069
Chemical and physical data
Formula	C19H17ClN2O
Molar mass	324.81 g·mol−1
3D model (JSmol)	Interactive image
SMILES Clc4cc\1c(N(C(=O)C/N=C/1c2ccccc2)CC3CC3)cc4
InChI InChI=1S/C19H17ClN2O/c20-15-8-9-17-16(10-15)19(14-4-2-1-3-5-14)21-11-18(23)22(17)12-13-6-7-13/h1-5,8-10,13H,6-7,11-12H2 Y Key:MWQCHHACWWAQLJ-UHFFFAOYSA-N Y
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Prazepam is a benzodiazepine derivative drug developed by Warner-Lambert in the 1960s.^[2] It possesses anxiolytic, anticonvulsant, sedative and skeletal muscle relaxant properties.^[3] Prazepam is a prodrug for desmethyldiazepam which is responsible for the therapeutic effects of prazepam.^[4]

Prazepam is indicated for the short-term treatment of anxiety. After short-term therapy, the dose is usually gradually tapered-off to reduce or avoid any withdrawal or rebound effects.^[5][6] Desmethyldiazepam, an active metabolite, has a very long half-life of 29 to 224 hours, which contributes to the therapeutic effects of prazepam.^[7][8]

Side effects of prazepam are less profound than with other benzodiazepines.^[9] Excessive drowsiness and with longer-term use, drug dependence, are the most common side effects of prazepam.^[10][11] Side effects such as fatigue or "feeling spacey" can also occur but less commonly than with other benzodiazepines. Other side effects include feebleness, clumsiness or lethargy, clouded thinking and mental slowness.^[12][13][14]

Tolerance and dependence can develop with long-term use of prazepam, and upon cessation or reduction in dosage, then a benzodiazepine withdrawal syndrome may occur with symptoms such as tremulousness, dysphoria, psychomotor agitation, tachycardia and sweating. In severe cases, hallucinations, psychosis and seizures can occur. Withdrawal-related psychosis is generally unresponsive to antipsychotic mediations. The risk and severity of the withdrawal syndrome increases the higher the dose and the longer prazepam is taken for.^[15] Tolerance, dependence and withdrawal problems may be less severe than with other benzodiazepines, such as diazepam.^[16] It may be because tolerance is slower to develop with prazepam than with other benzodiazepines.^[17] Abrupt or over-rapid discontinuation of prazepam after long-term use, even at low dosage, may result in a protracted withdrawal syndrome.^[18]

Benzodiazepines can induce serious problems of addiction, which is one of the main reasons for their use being restricted to short-term use. A survey in Senegal found that the majority of doctors believed that their training in this area was generally poor. It was recommended that national authorities take urgent action regarding the rational use of benzodiazepines. Almost one-fifth of doctors ignored prescription guidelines regarding short-term use of benzodiazepines, and almost three-quarters of doctors regarded their training and knowledge of benzodiazepines to be inadequate. More training regarding benzodiazepines has been recommended for doctors.^[19][20]

Benzodiazepines require special precaution if used in the elderly, during pregnancy, in children, alcohol or drug-dependent individuals and individuals with comorbid psychiatric disorders.^[21]

Prazepam exerts its therapeutic effects primarily via modulating the benzodiazepine receptor which in turn enhances GABA function in the brain.^[22] Prazepam like other benzodiazepines has anticonvulsant properties, but its anticonvulsant properties are not as potent as other benzodiazepines when tested in animal studies.^{[23][24][25][26]}

Prazepam is metabolised into descyclopropylmethylprazepam (also known as desmethyldiazepam) and 3-hydroxyprazepam which is further metabolised into oxazepam.^{[27][28][29][30][31]} Prazepam is a prodrug for descyclopropylmethylprazepam/desmethyldiazepam (also known as norprazepam or nordazepam) which is responsible for most of the therapeutic activity of prazepam rather than prazepam itself.^{[15][22][32][33]}

Prazepam may interact with cimetidine.^[34] Alcohol in combination with prazepam increases the adverse effects, particularly performance impairing side effects and drowsiness.^[35]

The symptoms of an overdose of prazepam include sleepiness, agitation and ataxia. Hypotonia may also occur in severe cases. Overdoses in children typically result in more severe symptoms of overdose.^[36]

Prazepam like other benzodiazepines has abuse potential and can be habit forming. However, its abuse potential may be lower than other benzodiazepines because it has a slow onset of action.^[15][37]

Animal studies have found prazepam taken during pregnancy results in delayed growth and causes reproductive abnormalities.^[38][39][40]

Common trade names include Centrac, Centrax, Demetrin, Lysanxia, Mono Demetrin, Pozapam, Prasepine, Prazene, Reapam and Trepidan. Trade names vary depending on the country; Austria: Demetrin, Belgium: Lysanxia, France: Lysanxia, Germany: Demetrin; Mono Demetrin, Greece: Centrac, Ireland: Centrax, Italy: Prazene; Trepidan, Macedonia: Demetrin, Prazepam, Netherlands: Reapam, Portugal: Demetrin, South Africa: Demetrin, Switzerland: Demetrin, Thailand: Pozapam; Prasepine.^[41]

• Benzodiazepine
• Benzodiazepine dependence
• Long-term effects of benzodiazepines

• Inchem – Prazepam