Clonazepam is a long-acting benzodiazepine with intermediate onset commonly used to treat panic disorders, severe anxiety, and seizures.

Brand Names
Clonapam, Klonopin, Rivotril
Generic Name
DrugBank Accession Number

A benzodiazepine used to treat various seizures, including myotonic or atonic seizures, photosensitive epilepsy, and absence seizures, although tolerance may develop.Label18,22,23,24 The agent has also been indicated for treating panic disorder.Label7,18,22,23,24 The mechanism of action appears to involve the enhancement of gamma-aminobutyric acid receptor responses.Label7,8,18,22,23,24

Since being first patented in 1960 and then released for sale from Roche in the US in 1975,16,17 clonazepam has experienced a storied history in the treatment of the aforementioned medical conditions. Now available as a generic medication, the agent continues to see exceptionally high use as millions of prescriptions are written for the medication internationally every year. Unfortunately, however, like most benzodiazepines, clonazepam use has also been associated with recreational use and drug abuse.Label18,22,23,24

Small Molecule
Approved, Illicit
Average: 315.711
Monoisotopic: 315.041068908
Chemical Formula
  • 1,3-dihydro-7-nitro-5-(2-chlorophenyl)-2H-1,4.benzodiazepin-2-one
  • 5-(2-chloro-phenyl)-7-nitro-1,3-dihydro-benzo[e][1,4]diazepin-2-one
  • 5-(2-chlorophenyl)-7-nitro-1H-benzo[e][1,4]diazepin-2(3H)-one
  • 5-(o-chlorophenyl)-7-nitro-1,3-dihydro-2H-1,4-benzodiazepin-2-one
  • Clonazepam
  • Clonazepamum
External IDs
  • RO 5-4023
  • RO-5-4023



Clonazepam is indicated as monotherapy or as an adjunct in the treatment of Lennox-Gastaut syndrome (petit mal variant), akinetic, and myoclonic seizures.Label23 Furthermore, clonazepam may also be of some value in patients with absence spells (petit mal) who have failed to respond to succinimides.Label23 Additionally, clonazepam is also indicated for the treatment of panic disorder, with or without agoraphobia, as defined in the DSM-V.Label

Alternatively, some regional prescribing information note that clonazepam is indicated for all clinical forms of epileptic disease and seizures in adults, especially absence seizures (petit mal) including atypical absence; primary or secondarily generalised tonic-clonic (grand mal), tonic or clonic seizures; partial (focal) seizures with elementary or complex symptomatology; various forms of myoclonic seizures, myoclonus and associated abnormal movements.18,24 Such regional label data also has clonazepam indicated for most types of epilepsy in infants and children, especially absences (petit mal), myoclonic seizures and tonic-clonic fits, whether due to primary generalized epilepsy or to secondary generalization of partial epilepsy.24

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Associated Conditions
Indication TypeIndicationCombined Product DetailsApproval LevelAge GroupPatient CharacteristicsDose Form
Management ofAkinetic seizures••••••••••••••••••
Management ofBurning mouth syndrome••• •••••
Management ofEssential tremor••• •••••
Adjunct therapy in management ofLennox-gastaut syndrome••••••••••••••••••
Management ofLennox-gastaut syndrome••••••••••••••••••
Contraindications & Blackbox Warnings
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The pharmacodynamic properties of clonazepam are common among benzodiazepines and include anticonvulsive, sedative, muscle relaxing and anxiolytic effects 6,18,22,23. Animal data and electroencephalographic investigations in man have shown that clonazepam rapidly suppresses many types of paroxysmal activity including the spike and wave discharge in absence seizures (petit mal), slow spike wave, generalized spike wave, spikes with temporal or other locations, as well as irregular spikes and waves Label 6,18,22,23. Moreover, the agent can also decrease the frequency, amplitude, duration, and spread of discharge in minor motor seizures Label 22.

Generalized EEG abnormalities are more readily suppressed by clonazepam than are focal EEG abnormalities such as focal spikes 18. Clonazepam has beneficial effects in generalized and focal epilepsies 18.

Mechanism of action

Gamma-Aminobutyric acid (GABA) is considered the principal inhibitory neurotransmitter in the human body 6,7,8. When GABA binds to GABA(a) receptors found in neuron synapses, chloride ions are conducted across neuron cell membranes via an ion channel in the receptors 6,7,8,23. With enough chloride ions conducted, the local, associated neuron membrane potentials are hyperpolarized - making it more difficult or less likely for action potentials to fire, ultimately resulting in less excitation of the neurons 6,7,8,23.

Subsequently, benzodiazepines like clonazepam can bind to benzodiazepine receptors that are components of various varieties of GABA(a) receptors 6,7,8,23,18,22. This binding acts to enhance the effects of GABA by increasing GABA affinity for the GABA(a) receptor, which ultimately enhances GABA ligand binding at the receptors 6,7,8,23,18,22. This enhanced ligand binding of the inhibitory neurotransmitter GABA to the receptors increases the aforementioned chloride ion conduction (perhaps reportedly via an increase in the frequency of the chloride channel opening), resulting in a hyperpolarized cell membrane that prevents further excitation of the associated neuron cells 6,7,8,23,18,22. Combined with the notion that such benzodiazepine receptor associated GABA(a) receptors exist both peripherally and in the CNS, this activity consequently facilitates various effects like sedation, hypnosis, skeletal muscle relaxation, anticonvulsant activity, and anxiolytic action 6,7,8,23,18,22.

In particular, when out of the ordinary rapid and repetitive electrical signals are released in the CNS, it is proposed that the brain can become over-stimulated and ordinary functions are disrupted - resulting in seizure activity 8. By enhancing the neuro-inhibitory activity of GABA, it is believed that clonazepam can facilitate in decreasing any excessive electrical nerve activity in the CNS that might be contributing to seizures 8. Concurrently, it is also believed that clonazepam's actions in enhancing GABA effects may inhibit neuronal activity proposed to occur in amygdala-centered fear circuits - therefore assisting in the management of anxiety or panic 7.

AGABA(A) Receptor
positive allosteric modulator
AGABA(A) Receptor Benzodiazepine Binding Site
UNuclear receptor subfamily 1 group I member 2
partial agonist

Clonazepam is rapidly and almost entirely absorbed after oral administration as tablets Label 22,24. Peak plasma concentrations of clonazepam administered by the oral route are reached within 1-4 hours and the associated absorption half-life is about 25 minutes Label 22,24. The absolute bioavailability is approximately 90% - but with substantially large differences between individuals Label 22,24.

Volume of distribution

Clonazepam distributes very rapidly to various organs and body tissues with preferential uptake by brain structures 22,24. The apparent volume of distribution has been documented as approximately 3 L/kg 22,24.

Protein binding

The recorded plasma protein binding of clonazepam ranges between 82–86% 22,24.


Clonazepam is metabolized principally in the liver 22,24. The metabolic pathways include hydroxylation, reduction of the nitro groups to amine groups, and the addition of acetate to the amino grouping 22,24. In particular, clonazepam is extensively metabolized by reduction to 7-amino-clonazepam and by N-acetylation to 7-acetamido-clonazepam 22,24. Hydroxylation at the C-3 position also occurs 22,24. Hepatic cytochrome P450 3A4 is implicated in the nitroreduction of clonazepam to pharmacologically inactive metabolites 22,24.

Hover over products below to view reaction partners

Route of elimination

Approximately 50-70% of a clonazepam dose is excreted in the urine and 10-30% is excreted in the feces as metabolites 22,24. The excretion of unchanged clonazepam in the urine is typically less than 2% of the administered dose 22,24. Metabolites of clonazepam are present in urine as both free and conjugated (glucuronide and sulfate) compounds 22,24.


The mean elimination half-life determined for clonazepam is independent of the dose given and has been documented as being about 30-40 hours 22,24.


The documented clearance for clonazepam is approximately 55 ml/min regardless of gender 22. Nevertheless, clearance values normalized by weight decline with increasing body weight 22.

Adverse Effects
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Benzodiazepines like clonazepam commonly cause drowsiness, ataxia, dysarthria, and nystagmus. Overdose with clonazepam is generally not life-threatening if the drug is taken alone, but may lead to areflexia, apnea, hypotension, cardiorespiratory depression, and coma. Coma, if it does occur, usually lasts a few hours but it can become more protracted and cyclical, especially in elderly patients. Increased frequency of seizures may occur in patients at supratherapeutic plasma concentrations. Benzodiazepine respiratory depressant effects are more serious when compounded in patients with respiratory disease.

An increased risk of congenital malformations associated with the use of benzodiazepine drugs like clonazepam has been suggested in several studies Label 22,24. There may also be non-teratogenic risks associated with the use of benzodiazepines during pregnancy Label 22,24. There have been reports of neonatal flaccidity, respiratory and feeding difficulties, and hypothermia in children born to mothers who have been receiving benzodiazepines late in pregnancy Label 22,24. In addition, children born to mothers receiving benzodiazepines late in pregnancy may be at some risk of experiencing withdrawal symptoms during the postnatal period Label 22,24. In general, it is best for patients who are of childbearing potential and also use benzodiazepines like clonazepam to discuss such matters with their health care professionals as careful consideration must be undertaken regarding the intersection of the risks of untreated seizure potential in the patient and any possible toxicity to the fetus Label 22,24.

Although the active ingredient of clonazepam has been found to pass into the maternal milk in small amounts only, mothers receiving clonazepam should not breast-feed their infants Label 22,24.

Since the possibility that adverse effects on the physical or mental development of the child could become apparent only after a number of years, the risk-benefit consideration of the long-term use of clonazepam in pediatric patients younger than five years of age is important Label 22,24.

The pharmacological effects of benzodiazepines like clonazepam appear to be greater in elderly patients than in younger patients even at similar plasma benzodiazepine concentrations, possibly because of age-related changes in drug-receptor interactions, post-receptor mechanisms, and organ function Label 22,24. In general elderly patients should be started on the lowest possible dose of clonazepam and observed closely Label 22,24. There is an increased risk for falls and fractures among elderly and debilitated benzodiazepine users Label 22,24. The risk is increased in those taking concomitant sedatives, including substances like benzodiazepines, alcoholic beverages, and so on Label 22,24.

Some oral LD50 values documented are >4000 mg/kg for the mouse model, >4000 mg/kg for the adult rat model, and >2000 mg/kg for the rabbit model 22.

Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
1,2-BenzodiazepineThe risk or severity of CNS depression can be increased when Clonazepam is combined with 1,2-Benzodiazepine.
AbacavirAbacavir may decrease the excretion rate of Clonazepam which could result in a higher serum level.
AbametapirThe serum concentration of Clonazepam can be increased when it is combined with Abametapir.
AceclofenacAceclofenac may decrease the excretion rate of Clonazepam which could result in a higher serum level.
AcemetacinAcemetacin may decrease the excretion rate of Clonazepam which could result in a higher serum level.
Food Interactions
  • Avoid alcohol.
  • Limit caffeine intake.
  • Take with or without food. The absorption is unaffected by food.


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Product Images
International/Other Brands
Antelepsin (AWD) / Iktorivil (Roche) / Rivotril (Roche)
Brand Name Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
ClonapamTablet0.5 mgOralBausch Health, Canada Inc.1997-01-31Not applicableCanada flag
ClonapamTablet2 mgOralBausch Health, Canada Inc.1997-02-28Not applicableCanada flag
ClonapamTablet1 mgOralBausch Health, Canada Inc.1997-01-31Not applicableCanada flag
ClonazepamTablet0.5 mgOralApotex Corporation1995-12-31Not applicableCanada flag
ClonazepamTablet2 mg/1OralWatson Pharmaceuticals2008-03-18Not applicableUS flag
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
Accel-clonazepamTablet0.5 mgOralAccel Pharma IncNot applicableNot applicableCanada flag
Accel-clonazepamTablet2.0 mgOralAccel Pharma IncNot applicableNot applicableCanada flag
Accel-clonazepamTablet1.0 mgOralAccel Pharma IncNot applicableNot applicableCanada flag
Apo-clonazepamTablet0.5 mgOralApotex Corporation1995-12-31Not applicableCanada flag
Apo-clonazepamTablet2 mgOralApotex Corporation1995-12-31Not applicableCanada flag


ATC Codes
N03AE01 — Clonazepam
Drug Categories
Chemical TaxonomyProvided by Classyfire
This compound belongs to the class of organic compounds known as 1,4-benzodiazepines. These are organic compounds containing a benzene ring fused to a 1,4-azepine.
Organic compounds
Super Class
Organoheterocyclic compounds
Sub Class
Direct Parent
Alternative Parents
Nitroaromatic compounds / Chlorobenzenes / Aryl chlorides / Cyclic carboximidic acids / Ketimines / Propargyl-type 1,3-dipolar organic compounds / Organic oxoazanium compounds / Azacyclic compounds / Organopnictogen compounds / Organooxygen compounds
show 4 more
1,4-benzodiazepine / Allyl-type 1,3-dipolar organic compound / Aromatic heteropolycyclic compound / Aryl chloride / Aryl halide / Azacycle / Benzenoid / C-nitro compound / Chlorobenzene / Cyclic carboximidic acid
show 19 more
Molecular Framework
Aromatic heteropolycyclic compounds
External Descriptors
monochlorobenzenes, 1,4-benzodiazepinone (CHEBI:3756)
Affected organisms
  • Humans and other mammals

Chemical Identifiers

CAS number
InChI Key


Synthesis Reference

Kariss, J. and Newmark, H.L.; US. Patents 3,116,203; December 31, 1963; and 3,123,529; March 3, 1964; both assigned to Hoffmann-LaRoche, Inc. Keller, O., Steiger, N. and Sternbach, L.H.; U S . Patents 3,121,114; February 11, 1964; and 3,203990; August 31, 1965; both assigned to Hoffmann-LaRoche, Inc. Focella, A. and Rachlin, A.I.; U.S. Patent 3,335,181; August 8, 1967; assigned to Hoffmann- LaRoche. Inc.

General References
  1. Dreifuss FE, Penry JK, Rose SW, Kupferberg HJ, Dyken P, Sato S: Serum clonazepam concentrations in children with absence seizures. Neurology. 1975 Mar;25(3):255-8. [Article]
  2. Robertson MD, Drummer OH: Postmortem drug metabolism by bacteria. J Forensic Sci. 1995 May;40(3):382-6. [Article]
  3. Rosen GM, Turner MJ 3rd: Synthesis of spin traps specific for hydroxyl radical. J Med Chem. 1988 Feb;31(2):428-32. [Article]
  4. Rosen GM, Demos HA, Rauckman EJ: Not all aromatic nitro compounds form free radicals. Toxicol Lett. 1984 Aug;22(2):145-52. [Article]
  5. Earley JV, Fryer RI, Ning RY: Quinazolines and 1,4-benzodiazepines. LXXXIX: Haptens useful in benzodiazepine immunoassay development. J Pharm Sci. 1979 Jul;68(7):845-50. [Article]
  6. DeVane CL, Ware MR, Lydiard RB: Pharmacokinetics, pharmacodynamics, and treatment issues of benzodiazepines: alprazolam, adinazolam, and clonazepam. Psychopharmacol Bull. 1991;27(4):463-73. [Article]
  7. Nardi AE, Machado S, Almada LF, Paes F, Silva AC, Marques RJ, Amrein R, Freire RC, Martin-Santos R, Cosci F, Hallak JE, Crippa JA, Arias-Carrion O: Clonazepam for the treatment of panic disorder. Curr Drug Targets. 2013 Mar;14(3):353-64. [Article]
  8. Jenner P, Pratt JA, Marsden CD: Mechanism of action of clonazepam in myoclonus in relation to effects on GABA and 5-HT. Adv Neurol. 1986;43:629-43. [Article]
  9. Grushka M, Epstein J, Mott A: An open-label, dose escalation pilot study of the effect of clonazepam in burning mouth syndrome. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998 Nov;86(5):557-61. doi: 10.1016/s1079-2104(98)90345-6. [Article]
  10. Thompson C, Lang A, Parkes JD, Marsden CD: A double-blind trial of clonazepam in benign essential tremor. Clin Neuropharmacol. 1984;7(1):83-8. doi: 10.1097/00002826-198403000-00004. [Article]
  11. Bottai T, Hue B, Hillaire-Buys D, Barbe A, Alric R, Pouget R, Petit P: Clonazepam in acute mania: time-blind evaluation of clinical response and concentrations in plasma. J Affect Disord. 1995 Dec 24;36(1-2):21-7. doi: 10.1016/0165-0327(95)00048-8. [Article]
  12. Thaker GK, Nguyen JA, Strauss ME, Jacobson R, Kaup BA, Tamminga CA: Clonazepam treatment of tardive dyskinesia: a practical GABAmimetic strategy. Am J Psychiatry. 1990 Apr;147(4):445-51. doi: 10.1176/ajp.147.4.445. [Article]
  13. Bagheri MM, Kerbeshian J, Burd L: Recognition and management of Tourette's syndrome and tic disorders. Am Fam Physician. 1999 Apr 15;59(8):2263-72, 2274. [Article]
  14. Roguski A, Rayment D, Whone AL, Jones MW, Rolinski M: A Neurologist's Guide to REM Sleep Behavior Disorder. Front Neurol. 2020 Jul 8;11:610. doi: 10.3389/fneur.2020.00610. eCollection 2020. [Article]
  15. Carlos K, Prado GF, Teixeira CD, Conti C, de Oliveira MM, Prado LB, Carvalho LB: Benzodiazepines for restless legs syndrome. Cochrane Database Syst Rev. 2017 Mar 20;3(3):CD006939. doi: 10.1002/14651858.CD006939.pub2. [Article]
  16. Fischer, Jnos; Ganellin, C. Robin (2006). Analogue-based Drug Discovery. John Wiley & Sons. [ISBN:9783527607495]
  17. Shorter, Edward (2005). A Historical Dictionary of Psychiatry. Oxford University Press. [ISBN:9780190292010]
  18. Electronic Medicines Compendium: Clonazepam Rosemont 2mg/5ml Oral Solution [Link]
  19. DailyMed Label: KLONOPIN (clonazepam) Oral Tablets [Link]
  20. FDA Approved Drug Products: KLONOPIN (clonazepam) tablets, for oral use [Link]
  21. Health Canada Approved Drug Proucts: Rivotril (Clonazepam) 0.5 mg and 2 mg Tablets, for oral use [Link]
  22. Rivotril (Clonazepam) 0.5 mg and 2 mg Tablets Canadian Product Monograph [File]
  23. Clonazepam Fact Sheet from [File]
  24. Rivotril (Clonazepam) Australian Product Information [File]
Human Metabolome Database
PubChem Compound
PubChem Substance
Therapeutic Targets Database
RxList Drug Page Drug Page
FDA label
Download (513 KB)
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Clinical Trials

Clinical Trials
4CompletedSupportive CareCerebral Palsy (CP) / Excessive crying / Pain1
4CompletedTreatmentFear of open spaces / Panic Disorder1
4CompletedTreatmentPost Traumatic Stress Disorder (PTSD)1
4CompletedTreatmentSocial Phobia1
4Not Yet RecruitingTreatmentPanic Disorder1


Not Available
  • Actavis Group
  • Aidarex Pharmacuticals LLC
  • Alphapharm Party Ltd.
  • Apotex Inc.
  • Apotheca Inc.
  • A-S Medication Solutions LLC
  • Barr Pharmaceuticals
  • Bryant Ranch Prepack
  • Caraco Pharmaceutical Labs
  • Cardinal Health
  • Caremark LLC
  • Catalent Pharma Solutions
  • Cebert Pharmaceuticals Inc.
  • Centaur Pharmaceuticals Pvt Ltd.
  • Comprehensive Consultant Services Inc.
  • Corepharma LLC
  • Coupler Enterprises Inc.
  • Direct Dispensing Inc.
  • Dispensing Solutions
  • Diversified Healthcare Services Inc.
  • Eon Labs
  • F Hoffmann-La Roche Ltd.
  • Golden State Medical Supply Inc.
  • Goldline Laboratories Inc.
  • H.J. Harkins Co. Inc.
  • Heartland Repack Services LLC
  • Innoviant Pharmacy Inc.
  • Kali Laboratories Inc.
  • Keltman Pharmaceuticals Inc.
  • Lake Erie Medical and Surgical Supply
  • Liberty Pharmaceuticals
  • Major Pharmaceuticals
  • Mckesson Corp.
  • Murfreesboro Pharmaceutical Nursing Supply
  • Mylan
  • Novopharm Ltd.
  • Nucare Pharmaceuticals Inc.
  • Palmetto Pharmaceuticals Inc.
  • Par Pharmaceuticals
  • PD-Rx Pharmaceuticals Inc.
  • Physicians Total Care Inc.
  • Preferred Pharmaceuticals Inc.
  • Prepackage Specialists
  • Prepak Systems Inc.
  • Qualitest
  • Rebel Distributors Corp.
  • Recalcine Laboratorios
  • Redpharm Drug
  • Remedy Repack
  • Sandhills Packaging Inc.
  • Sanofi-Aventis Inc.
  • Southwood Pharmaceuticals
  • St Mary's Medical Park Pharmacy
  • Stat Rx Usa
  • Syntex SA
  • Teva Pharmaceutical Industries Ltd.
  • Torpharm Inc.
  • UDL Laboratories
  • Va Cmop Dallas
  • Vintage Pharmaceuticals Inc.
Dosage Forms
TabletOral1.0 mg
TabletOral2.0 mg
SolutionOral0.25 g
TabletOral0.100 mg
TabletOral0.5 mg/1
TabletOral1 mg/1
TabletOral2 mg/1
Tablet, film coatedOral
Tablet, orally disintegratingOral.25 mg/1
Tablet, orally disintegratingOral.5 mg/1
Tablet, orally disintegratingOral0.125 mg/1
Tablet, orally disintegratingOral0.25 mg/1
Tablet, orally disintegratingOral0.5 mg/1
Tablet, orally disintegratingOral1 mg/1
Tablet, orally disintegratingOral2 mg/1
SolutionOral250000 mg
TabletOral.5 mg
TabletOral2.000 mg
Tablet, coatedOral0.5 mg
Tablet, coatedOral2 mg
TabletOral.5 mg/1
WaferOral0.125 mg/1
WaferOral0.25 mg/1
WaferOral0.5 mg/1
WaferOral1 mg/1
WaferOral2 mg/1
SolutionOral2.500 mg
SolutionParenteral1.00 mg
SolutionOral2.50 mg
SolutionOral250.000 mg
TabletOral0.25 mg
TabletOral1 mg
Tablet, film coatedOral2 MG
TabletOral2.00 mg
Solution / dropsOral2.5 MG/ML
TabletOral0.500 mg
TabletOral2 mg
Injection, solutionIntravenous1 mg/1ml
Solution / dropsOral2.5 mg/1ml
SolutionIntramuscular; Intravenous1 mg
TabletOral0.5 mg
TabletOral200000 mg
SolutionOral2.5 mg
Unit descriptionCostUnit
Klonopin 2 mg tablet2.85USD tablet
Klonopin 1 mg tablet2.17USD tablet
Klonopin 0.5 mg tablet1.91USD tablet
ClonazePAM ODT 2 mg Dispersible Tablet1.67USD dispersible tablet
ClonazePAM ODT 0.25 mg Dispersible Tablet1.22USD dispersible tablet
ClonazePAM ODT 0.5 mg Dispersible Tablet1.18USD dispersible tablet
ClonazePAM ODT 0.125 mg Dispersible Tablet1.17USD dispersible tablet
ClonazePAM ODT 1 mg Dispersible Tablet1.1USD dispersible tablet
Clonazepam 2 mg tablet0.81USD tablet
Clonazepam 1 mg tablet0.63USD tablet
Clonazepam 0.5 mg tablet0.61USD tablet
Rivotril 2 mg Tablet0.38USD tablet
Rivotril 0.5 mg Tablet0.22USD tablet
Apo-Clonazepam 2 mg Tablet0.21USD tablet
Co Clonazepam 2 mg Tablet0.21USD tablet
Mylan-Clonazepam 2 mg Tablet0.21USD tablet
Novo-Clonazepam 2 mg Tablet0.21USD tablet
Phl-Clonazepam 2 mg Tablet0.21USD tablet
Pms-Clonazepam 2 mg Tablet0.21USD tablet
Ratio-Clonazepam 2 mg Tablet0.21USD tablet
Sandoz Clonazepam 2 mg Tablet0.21USD tablet
Co Clonazepam 1 mg Tablet0.19USD tablet
Phl-Clonazepam 1 mg Tablet0.19USD tablet
Pms-Clonazepam 1 mg Tablet0.19USD tablet
Sandoz Clonazepam 1 mg Tablet0.19USD tablet
Apo-Clonazepam 0.5 mg Tablet0.12USD tablet
Co Clonazepam 0.5 mg Tablet0.12USD tablet
Mylan-Clonazepam 0.5 mg Tablet0.12USD tablet
Novo-Clonazepam 0.5 mg Tablet0.12USD tablet
Phl-Clonazepam 0.5 mg Tablet0.12USD tablet
Phl-Clonazepam-R 0.5 mg Tablet0.12USD tablet
Pms-Clonazepam 0.5 mg Tablet0.12USD tablet
Pms-Clonazepam-R 0.5 mg Tablet0.12USD tablet
Ratio-Clonazepam 0.5 mg Tablet0.12USD tablet
Sandoz Clonazepam 0.5 mg Tablet0.12USD tablet
Pms-Clonazepam 0.25 mg Tablet0.07USD tablet
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Not Available


Experimental Properties
melting point (°C)238-240Kariss, J. and Newmark, H.L.; US. Patents 3,116,203; December 31, 1963; and 3,123,529; March 3, 1964; both assigned to Hoffmann-LaRoche, Inc. Keller, O., Steiger, N. and Sternbach, L.H.; U S . Patents 3,121,114; February 11, 1964; and 3,203990; August 31, 1965; both assigned to Hoffmann-LaRoche, Inc. Focella, A. and Rachlin, A.I.; U.S. Patent 3,335,181; August 8, 1967; assigned to Hoffmann- LaRoche. Inc.
water solubility100 mg/L (at 25 °C)MERCK INDEX (1996)
logP2.41HANSCH,C ET AL. (1995)
Predicted Properties
Water Solubility0.0106 mg/mLALOGPS
pKa (Strongest Acidic)11.65Chemaxon
pKa (Strongest Basic)1.89Chemaxon
Physiological Charge0Chemaxon
Hydrogen Acceptor Count4Chemaxon
Hydrogen Donor Count1Chemaxon
Polar Surface Area84.6 Å2Chemaxon
Rotatable Bond Count2Chemaxon
Refractivity83.02 m3·mol-1Chemaxon
Polarizability29.66 Å3Chemaxon
Number of Rings3Chemaxon
Rule of FiveYesChemaxon
Ghose FilterYesChemaxon
Veber's RuleNoChemaxon
MDDR-like RuleNoChemaxon
Predicted ADMET Features
Human Intestinal Absorption+0.9946
Blood Brain Barrier+0.9718
Caco-2 permeable+0.5313
P-glycoprotein substrateSubstrate0.5594
P-glycoprotein inhibitor INon-inhibitor0.8474
P-glycoprotein inhibitor IINon-inhibitor0.9157
Renal organic cation transporterNon-inhibitor0.8179
CYP450 2C9 substrateNon-substrate0.7777
CYP450 2D6 substrateNon-substrate0.8934
CYP450 3A4 substrateSubstrate0.7295
CYP450 1A2 substrateInhibitor0.7646
CYP450 2C9 inhibitorInhibitor0.5213
CYP450 2D6 inhibitorNon-inhibitor0.8271
CYP450 2C19 inhibitorInhibitor0.7441
CYP450 3A4 inhibitorInhibitor0.5565
CYP450 inhibitory promiscuityHigh CYP Inhibitory Promiscuity0.7255
Ames testNon AMES toxic0.6778
BiodegradationNot ready biodegradable1.0
Rat acute toxicity1.6422 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9821
hERG inhibition (predictor II)Non-inhibitor0.8734
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)


Mass Spec (NIST)
Not Available
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSsplash10-02br-1190000000-1354614c337562e212cc
Mass Spectrum (Electron Ionization)MSsplash10-02a9-2492000000-109e2626e8a128b9e433
Predicted 1H NMR Spectrum1D NMRNot Applicable
Predicted 13C NMR Spectrum1D NMRNot Applicable
Chromatographic Properties
Collision Cross Sections (CCS)
AdductCCS Value (Å2)Source typeSource
DarkChem Lite v0.1.0
DeepCCS 1.0 (2019)
DarkChem Lite v0.1.0
DeepCCS 1.0 (2019)
DarkChem Lite v0.1.0
DeepCCS 1.0 (2019)


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Protein group
Pharmacological action
Positive allosteric modulator
Curator comments
The GABA(A) receptor is pentameric (i.e. comprising 5 subunit proteins) and therefore has a multitude of potential isoforms. The above target is a collection of all possible GABA(A) subunits that may participate in the formation of the pentameric receptor and is not meant to imply direct a drug-protein interaction for each individual subunit.
General Function
Inhibitory extracellular ligand-gated ion channel activity
Specific Function
Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine...

  1. Mohler H, Fritschy JM, Rudolph U: A new benzodiazepine pharmacology. J Pharmacol Exp Ther. 2002 Jan;300(1):2-8. [Article]
  2. Riss J, Cloyd J, Gates J, Collins S: Benzodiazepines in epilepsy: pharmacology and pharmacokinetics. Acta Neurol Scand. 2008 Aug;118(2):69-86. doi: 10.1111/j.1600-0404.2008.01004.x. Epub 2008 Mar 31. [Article]
Protein group
Pharmacological action
Curator comments
Benzodiazepines modulate GABA(A) function by binding at the interface between alpha (α) and gamma (γ) subunits. Of the 6 α-subunits, only 4 (α-1, -2, -3, and -5) participate in the formation of this binding site. The above target is a collection of all α- and γ-subunits that are known to participate in the formation of the benzodiazepine binding site.
General Function
Inhibitory extracellular ligand-gated ion channel activity
Specific Function
Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine...

  1. Sigel E, Steinmann ME: Structure, function, and modulation of GABA(A) receptors. J Biol Chem. 2012 Nov 23;287(48):40224-31. doi: 10.1074/jbc.R112.386664. Epub 2012 Oct 4. [Article]
  2. Zhu S, Noviello CM, Teng J, Walsh RM Jr, Kim JJ, Hibbs RE: Structure of a human synaptic GABAA receptor. Nature. 2018 Jul;559(7712):67-72. doi: 10.1038/s41586-018-0255-3. Epub 2018 Jun 27. [Article]
Pharmacological action
Partial agonist
General Function
Zinc ion binding
Specific Function
Nuclear receptor that binds and is activated by variety of endogenous and xenobiotic compounds. Transcription factor that activates the transcription of multiple genes involved in the metabolism an...
Gene Name
Uniprot ID
Uniprot Name
Nuclear receptor subfamily 1 group I member 2
Molecular Weight
49761.245 Da
  1. Creusot N, Kinani S, Balaguer P, Tapie N, LeMenach K, Maillot-Marechal E, Porcher JM, Budzinski H, Ait-Aissa S: Evaluation of an hPXR reporter gene assay for the detection of aquatic emerging pollutants: screening of chemicals and application to water samples. Anal Bioanal Chem. 2010 Jan;396(2):569-83. doi: 10.1007/s00216-009-3310-y. Epub 2009 Nov 29. [Article]


Pharmacological action
General Function
Steroid hydroxylase activity
Specific Function
Metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. Inactivates a number of drugs and xenobiotics and also bioactivates many xenobiotic substrates to their hepatotoxic ...
Gene Name
Uniprot ID
Uniprot Name
Cytochrome P450 2E1
Molecular Weight
56848.42 Da
  1. Tassaneeyakul W, Birkett DJ, Miners JO: Inhibition of human hepatic cytochrome P4502E1 by azole antifungals, CNS-active drugs and non-steroidal anti-inflammatory agents. Xenobiotica. 1998 Mar;28(3):293-301. doi: 10.1080/004982598239579 . [Article]
Pharmacological action
General Function
Arylamine n-acetyltransferase activity
Specific Function
Participates in the detoxification of a plethora of hydrazine and arylamine drugs. Catalyzes the N- or O-acetylation of various arylamine and heterocyclic amine substrates and is able to bioactivat...
Gene Name
Uniprot ID
Uniprot Name
Arylamine N-acetyltransferase 2
Molecular Weight
33542.235 Da
  1. Olivera M, Martinez C, Gervasini G, Carrillo JA, Ramos S, Benitez J, Garcia-Martin E, Agundez JA: Effect of common NAT2 variant alleles in the acetylation of the major clonazepam metabolite, 7-aminoclonazepam. Drug Metab Lett. 2007 Jan;1(1):3-5. [Article]
  2. Miller ME, Garland WA, Min BH, Ludwick BT, Ballard RH, Levy RH: Clonazepam acetylation in fast and slow acetylators. Clin Pharmacol Ther. 1981 Sep;30(3):343-7. [Article]
Pharmacological action
General Function
Vitamin d3 25-hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation react...
Gene Name
Uniprot ID
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da
  1. Seree EJ, Pisano PJ, Placidi M, Rahmani R, Barra YA: Identification of the human and animal hepatic cytochromes P450 involved in clonazepam metabolism. Fundam Clin Pharmacol. 1993;7(2):69-75. [Article]


Pharmacological action
General Function
Toxic substance binding
Specific Function
Serum albumin, the main protein of plasma, has a good binding capacity for water, Ca(2+), Na(+), K(+), fatty acids, hormones, bilirubin and drugs. Its main function is the regulation of the colloid...
Gene Name
Uniprot ID
Uniprot Name
Serum albumin
Molecular Weight
69365.94 Da
  1. Pacifici GM, Viani A, Rizzo G, Carrai M, Rane A: Plasma protein binding of clonazepam in hepatic and renal insufficiency and after hemodialysis. Ther Drug Monit. 1987 Dec;9(4):369-73. [Article]

Drug created at June 13, 2005 13:24 / Updated at April 12, 2024 17:11