Clonazepam

Clonazepam

Clinical data
Trade names	Klonopin, Rivotril, others
AHFS/Drugs.com	Monograph
MedlinePlus	a682279
License data	US FDA: Clonazepam
Pregnancy category	AU: C US: D (Evidence of risk)
Dependence liability	Moderate
Routes of administration	by mouth, intramuscular, intravenous, sublingual
ATC code	N03AE01 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) CA: Schedule IV DE: Anlage III (Prescription only) UK: Class C US: Schedule IV UN: Psychotropic Schedule IV
Pharmacokinetic data
Bioavailability	90%
Protein binding	~85%
Metabolism	Liver CYP3A4
Onset of action	Within an hour
Biological half-life	15–50 hours
Duration of action	6–12 hours
Excretion	Kidney
Identifiers
IUPAC name 5-(2-Chlorophenyl)-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one
CAS Number	1622-61-3 Y
PubChem (CID)	2802
IUPHAR/BPS	6963
DrugBank	DB01068 Y
ChemSpider	2700 Y
UNII	5PE9FDE8GB Y
KEGG	D00280 Y
ChEBI	CHEBI:3756 Y
ChEMBL	CHEMBL452 Y
ECHA InfoCard	100.015.088
Chemical and physical data
Formula	C15H10ClN3O3
Molar mass	315.715
3D model (Jmol)	Interactive image
SMILES [O-] [N+](C1=CC2=C(C=C1)NC(CN=C2C3=CC=CC=C3Cl)=O)=O
InChI InChI=1S/C15H10ClN3O3/c16-12-4-2-1-3-10(12)15-11-7-9(19(21)22)5-6-13(11)18-14(20)8-17-15/h1-7H,8H2,(H,18,20) Y Key:DGBIGWXXNGSACT-UHFFFAOYSA-N Y

Clonazepam, sold under the brand name Klonopin among others, is a medication used to prevent and treat seizures, panic disorder, and for the movement disorder known as akathisia. It is a tranquilizer of the benzodiazepine class. It is taken by mouth. It begins having an effect within an hour and lasts between six and 12 hours.

Common side effects include sleepiness, poor coordination, and agitation. Long-term use may result in tolerance, dependence, and withdrawal symptoms if stopped abruptly. Dependence occurs in one-third of people who take clonazepam for longer than four weeks. It may increase risk of suicide in people who are depressed. If used during pregnancy it may result in harm to the baby. It binds to GABA_A receptors and increases the effect of the neurotransmitter GABA.

Clonazepam was initially patented in 1964 and went on sale in the United States in 1975. It is available as a generic medication. The wholesale cost in the developing world is between US$0.01 and US$0.07 per pill. In the United States the pills are about 0.40 USD each. In many areas of the world it is commonly used as a recreational drug.

Clonazepam may be prescribed for epilepsy or anxiety disorders.

Clonazepam, like other benzodiazepines, while being a first-line treatment for acute seizures, is not suitable for the long-term treatment of seizures due to the development of tolerance to the anticonvulsant effects.

Clonazepam has been found effective in treating epilepsy in children, and the inhibition of seizure activity seemed to be achieved at low plasma levels of clonazepam. As a result, clonazepam is sometimes used for certain rare childhood epilepsies; however, it has been found to be ineffective in the control of infantile spasms. Clonazepam is mainly prescribed for the acute management of epilepsies. Clonazepam has been found to be effective in the acute control of non-convulsive status epilepticus; however, the benefits tended to be transient in many of the people, and the addition of phenytoin for lasting control was required in these patients.