Clonazepam
/api/v1/drug/clonazepamBoxed warning
RISKS FROM CONCOMITANT USE WITH OPIOIDS; ABUSE, MISUSE, AND ADDICTION; and DEPENDENCE AND WITHDRAWAL REACTIONS Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Follow patients for signs and symptoms of respiratory depression and sedation (see WARNINGS and PRECAUTIONS ). The use of benzodiazepines, including clonazepam tablets, exposes users to risks of abuse, misuse, and addiction, which can lead to overdose or death. Abuse and misuse of benzodiazepines commonly involve concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes. Before prescribing clonazepam tablets and throughout treatment, assess each patient’s risk for abuse, misuse, and addiction (see WARNINGS ). The continued use of benzodiazepines, including clonazepam tablets, may lead to clinically significant physical dependence. The risks of dependence and withdrawal increase with longer treatment duration and higher daily dose. Abrupt discontinuation or rapid dosage reduction of clonazepam tablets after continued use may precipitate acute withdrawal reactions, which can be life-threatening.
Mechanism of action
Sourced from openFDAMechanism-of-action class: GABA A Modulators.
Indications
Sourced from openFDA- Seizure Disorders: Clonazepam tablets are useful alone or as an adjunct in the treatment of the Lennox-Gastaut syndrome (petit mal variant), akinetic, and myoclonic seizures. In patients with absence seizures (petit mal) who have failed to respond to succinimides, clonazepam tablets may be useful.ICD-10: G40.909
Contraindications
Sourced from openFDA- Clonazepam tablets are contraindicated in patients with the following conditions: History of sensitivity to benzodiazepines Clinical or biochemical evidence of significant liver disease Acute narrow angle glaucoma (it may be used in patients with open angle glaucoma who are receiving appropriate therapy).contraindicated
Dosage & administration
Sourced from openFDAClonazepam is available as a tablet. The tablets should be administered with water by swallowing the tablet whole. Seizure Disorders: The use of multiple anticonvulsants may result in an increase of CNS depressant adverse effects. This should be considered before adding clonazepam tablets to an existing anticonvulsant regimen. Adults: The initial dose for adults with seizure disorders should not exceed 1.5 mg/day divided into three doses. Dosage may be increased in increments of 0.5 mg to 1 mg every 3 days until seizures are adequately controlled or until side effects preclude any further increase. Maintenance dosage must be individualized for each patient depending upon response. Maximum recommended daily dose is 20 mg. Pediatric Patients: Clonazepam tablets are administered orally. In order to minimize drowsiness, the initial dose for infants and children (up to 10 years of age or 30 kg of body weight) should be between 0.01 and 0.03 mg/kg/day but not to exceed 0.05 mg/kg/day given in two or three divided doses. Dosage should be increased by no more than 0.25 mg to 0.5 mg every third day until a daily maintenance dose of 0.1 to 0.2 mg/kg of body weight has been reached, unless seizures are controlled or side effects preclude further increase. Whenever possible, the daily dose should be divided into three equal doses. If doses are not equally divided, the largest dose should be given before retiring. Geriatric Patients: There is no clinical trial experience with clonazepam tablets in seizure disorder patients 65 years of age and older.
Warnings & precautions
Sourced from openFDARisks from Concomitant Use with Opioids: Concomitant use of benzodiazepines, including clonazepam tablets, and opioids may result in profound sedation, respiratory depression, coma, and death. Because of these risks, reserve concomitant prescribing of benzodiazepines and opioids for patients for whom alternative treatment options are inadequate. Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioids alone. If a decision is made to prescribe clonazepam tablets concomitantly with opioids, prescribe the lowest effective dosages and minimum durations of concomitant use, and follow patients closely for signs and symptoms of respiratory depression and sedation. Advise both patients and caregivers about the risks of respiratory depression and sedation when clonazepam tablets are used with opioids (see PRECAUTIONS: Information for Patients and PRECAUTIONS: Drug Interactions ). Abuse, Misuse, and Addiction: The use of benzodiazepines, including clonazepam tablets, exposes users to the risks of abuse, misuse, and addiction, which can lead to overdose or death. Abuse and misuse of benzodiazepines often (but not always) involve the use of doses greater than the maximum recommended dosage and commonly involve concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes, including respiratory depression, overdose, or death (see DRUG ABUSE AND DEPENDENCE: Abuse ).
Adverse reactions
Sourced from openFDAThe adverse experiences for clonazepam tablets are provided separately for patients with seizure disorders and with panic disorder. Seizure Disorders: The most frequently occurring side effects of clonazepam tablets are referable to CNS depression. Experience in treatment of seizures has shown that drowsiness has occurred in approximately 50% of patients and ataxia in approximately 30%. In some cases, these may diminish with time; behavior problems have been noted in approximately 25% of patients. Others, listed by system, including those identified during postapproval use of clonazepam tablets are: Cardiovascular: Palpitations Dermatologic: Hair loss, hirsutism, skin rash, ankle and facial edema Gastrointestinal: Anorexia, coated tongue, constipation, diarrhea, dry mouth, encopresis, gastritis, increased appetite, nausea, sore gums Genitourinary: Dysuria, enuresis, nocturia, urinary retention Hematopoietic: Anemia, leukopenia, thrombocytopenia, eosinophilia Hepatic: Hepatomegaly, transient elevations of serum transaminases and alkaline phosphatase Musculoskeletal: Muscle weakness, pains Miscellaneous: Dehydration, general deterioration, fever, lymphadenopathy, weight loss or gain Neurologic: Abnormal eye movements, aphonia, choreiform movements, coma, diplopia, dysarthria, dysdiadochokinesis, ‘‘glassy-eyed’’ appearance, headache, hemiparesis, hypotonia, nystagmus, respiratory depression, slurred speech, tremor, vertigo Psychiatric: Confusion, depression, amnesia, hysteria, increased libido, insomnia, psychosis (the behavior effects are more likely to occur in patients with…
Use in specific populations
Sourced from openFDAPregnancy: Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, such as clonazepam tablets, during pregnancy. Healthcare providers are encouraged to recommend that pregnant women taking clonazepam tablets enroll in the NAAED Pregnancy Registry by calling 1-888-233-2334 or online at http://www.aedpregnancyregistry.org/. Risk Summary Neonates born to mothers using benzodiazepines late in pregnancy have been reported to experience symptoms of sedation and/or neonatal withdrawal (see WARNINGS: Neonatal Sedation and Withdrawal Syndrome, and Clinical Considerations ). Available data from published observational studies of pregnant women exposed to benzodiazepines do not report a clear association with benzodiazepines and major birth defects (see Data ). Administration of clonazepam to pregnant rabbits during the period of organogenesis resulted in developmental toxicity, including increased incidences of fetal malformations, at doses similar to or below therapeutic doses in patients (see Animal Data). Data for other benzodiazepines suggest the possibility of long-term effects on neurobehavioral and immunological function in animals following prenatal exposure to benzodiazepines at clinically relevant doses. The background risk of major birth defects and miscarriage for the indicated population is unknown.
Pharmacokinetics
Sourced from openFDA- Metabolism
- Clonazepam is rapidly and completely absorbed after oral administration. The absolute bioavailability of clonazepam is about 90%.
Overdosage
Sourced from openFDAOverdosage of benzodiazepines is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur. In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of benzodiazepines in combination with other CNS depressants (including alcohol and opioids) may be fatal (see WARNINGS: Abuse, Misuse, and Addiction ). Markedly abnormal (lowered or elevated) blood pressure, heart rate, or respiratory rate raise the concern that additional drugs and/or alcohol are involved in the overdosage. In managing benzodiazepine overdosage, employ general supportive measures, including intravenous fluids and airway maintenance.
Approval history
Sourced from openFDA- Jun 4, 1975NDANDA017533Cheplapharm
- Sep 10, 1996ANDAANDA074569Teva
- Sep 30, 1997ANDAANDA074925Chartwell Rx
- Oct 5, 1998ANDAANDA075150Aurobindo Pharma Usa
- Oct 6, 2000ANDAANDA075468Rubicon Research
- May 2, 2005ANDAANDA077147Accord Hlthcare
- Aug 3, 2005ANDAANDA077171Ph Health
- Aug 10, 2005ANDAANDA077194Barr
FDA shortages
Reference statistics from the openFDA drug-shortage dataset. For a live view, consult the FDA database directly. Not clinical guidance.
- Clonazepam, Tablet, .5 mg (NDC 0093-0832-01)ActiveSponsor: Teva Pharmaceuticals USA, Inc. · Reason: OtherUpdated
- Clonazepam, Tablet, .5 mg (NDC 0093-0832-05)ActiveSponsor: Teva Pharmaceuticals USA, Inc.Updated
- Clonazepam, Tablet, .5 mg (NDC 16729-136-00)ActiveSponsor: Accord Healthcare Inc.Updated
- Clonazepam, Tablet, .5 mg (NDC 16729-136-16)ActiveSponsor: Accord Healthcare Inc.Updated
- Clonazepam, Tablet, .5 mg (NDC 43547-406-10)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, .5 mg (NDC 43547-406-11)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, .5 mg (NDC 43547-406-50)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, .5 mg (NDC 59651-722-01)ActiveSponsor: Aurobindo Pharma USAUpdated
- Clonazepam, Tablet, .5 mg (NDC 59651-722-99)ActiveSponsor: Aurobindo Pharma USAUpdated
- Clonazepam, Tablet, .5 mg (NDC 72888-152-00)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, .5 mg (NDC 72888-152-01)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, .5 mg (NDC 72888-152-05)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, .5 mg (NDC 72888-152-30)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 1 mg (NDC 0093-3212-01)ActiveSponsor: Teva Pharmaceuticals USA, Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 0093-3212-05)ActiveSponsor: Teva Pharmaceuticals USA, Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 16729-137-00)ActiveSponsor: Accord Healthcare Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 16729-137-16)ActiveSponsor: Accord Healthcare Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 43547-407-10)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 43547-407-11)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 43547-407-50)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, 1 mg (NDC 59651-723-01)ActiveSponsor: Aurobindo Pharma USAUpdated
- Clonazepam, Tablet, 1 mg (NDC 59651-723-99)ActiveSponsor: Aurobindo Pharma USAUpdated
- Clonazepam, Tablet, 1 mg (NDC 72888-153-00)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 1 mg (NDC 72888-153-01)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 1 mg (NDC 72888-153-05)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 1 mg (NDC 72888-153-30)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 2 mg (NDC 0093-3213-01)ActiveSponsor: Teva Pharmaceuticals USA, Inc.Updated
- Clonazepam, Tablet, 2 mg (NDC 0093-3213-05)ActiveSponsor: Teva Pharmaceuticals USA, Inc.Updated
- Clonazepam, Tablet, 2 mg (NDC 16729-138-00)ActiveSponsor: Accord Healthcare Inc.Updated
- Clonazepam, Tablet, 2 mg (NDC 16729-138-16)ActiveSponsor: Accord Healthcare Inc.Updated
- Clonazepam, Tablet, 2 mg (NDC 43547-408-10)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, 2 mg (NDC 43547-408-50)ActiveSponsor: Prinston Pharmaceutical, Inc.Updated
- Clonazepam, Tablet, 2 mg (NDC 59651-724-01)ActiveSponsor: Aurobindo Pharma USAUpdated
- Clonazepam, Tablet, 2 mg (NDC 59651-724-05)ActiveSponsor: Aurobindo Pharma USAUpdated
- Clonazepam, Tablet, 2 mg (NDC 72888-154-01)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 2 mg (NDC 72888-154-05)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Clonazepam, Tablet, 2 mg (NDC 72888-154-30)ActiveSponsor: Rubicon Research Private LimitedUpdated
- Klonopin, Tablet, .5 mg (NDC 61269-605-10)ActiveSponsor: Cheplapharm Arzneimittel GmbHUpdated
- Klonopin, Tablet, 1 mg (NDC 61269-610-10)ActiveSponsor: Cheplapharm Arzneimittel GmbHUpdated
- Klonopin, Tablet, 2 mg (NDC 61269-620-10)ActiveSponsor: Cheplapharm Arzneimittel GmbHUpdated
FAERS reports
- 1Drug Ineffective13,7588.8%
- 2Fatigue10,3586.6%
- 3Nausea9,6926.2%
- 4Anxiety8,8095.6%
- 5Headache8,6665.5%
- 6Depression8,1905.2%
- 7Pain8,1355.2%
- 8Off Label Use7,8415.0%
- 9Dizziness7,3154.7%
- 10Insomnia7,0684.5%
- 11Dyspnoea6,9394.4%
- 12Diarrhoea6,7084.3%
- 13Fall6,7084.3%
- 14Vomiting6,4084.1%
- 15Malaise6,0743.9%
Literature
Recent PubMed references pinned to Clonazepam as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.
- Effective treatment for lithium pilocarpine-induced status epilepticus: clonazepam and lacosamide combination.Epilepsy & behavior : E&B · 2026 · Demirtas C, Akca M, Aykin U, et al.PMID 42166925DOI 10.1016/j.yebeh.2026.111092
- Alteration of Mitochondrial Ca2+ Fluxes by Kaempferol and CGP-37157 Regulates Ca2+ Oscillations in Human Alveolar Type 2 A549 Cells.Physiological research · 2026 · Wu KC, Chen CY, Shiao LR, et al.PMID 41823096DOI 10.33549/physiolres.935636
- Effects of clonazepam on developmental stages of Calliphora vicina Robineau-Desvoidy 1830 (Diptera: Calliphoridae) and its implications for PMI estimation.Journal of forensic and legal medicine · 2026 · Ayaz B, Altunsoy FPMID 41701994DOI 10.1016/j.jflm.2026.103093
- Solvent-induced photophysical properties and stability of clonazepam and Chlordiazepoxide.Scientific reports · 2025 · Kian R, Zakerhamidi MS, Merajin ZA, et al.PMID 41390532DOI 10.1038/s41598-025-30955-w
- Case series: Clinical management strategies of pediatric clonazepam poisoning informed by pharmacokinetics.Science progress · 2025 · Zhuang R, Zhang Q, Miao H, et al.PMID 41295449DOI 10.1177/00368504251401245
- Activation of GABA transmission by clonazepam reverses the autistic-like phenotypes of the Cav3.2 knockout mice.Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics · 2025 · Liang SF, Ming Y, Huang HT, et al.PMID 41067956DOI 10.1016/j.neurot.2025.e00761
- Development and Validation of an LC-MS/MS Method for the Simultaneous Determination of Alprazolam, Bromazepam, Clonazepam, Diazepam and Flunitrazpam in Human Urine and Its Application to Samples from Suspected Drug Abusers.Molecules (Basel, Switzerland) · 2025 · Kamal H, Gandhi V, Akil L, et al.PMID 40941979DOI 10.3390/molecules30173451
- Log-probit accompanied with Tallarida and Chou-Talalay-Martin methods in an isobolographic analysis of interactions between two antiseizure medications - a comparative study.Pharmacological reports : PR · 2025 · Łuszczki JJ, Gustaw-Rothenberg K, Florek-Łuszczki M, et al.PMID 40911251DOI 10.1007/s43440-025-00784-9
Clinical trials
The 10 most recently updated of 55 ClinicalTrials.gov registrations naming Clonazepam as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.
- Τhe Combination of Pharmacotherapy With RECOVERYTRSGR and RECOVERYTRSBDGR.Active not recruiting · Phase 4 · Interventional · 84 enrolled · Dr. Stavroula RakitziNCT07047651updated 2026-05-01
- Management of Catatonic Features in Adolescents With Profound AutismActive not recruiting · Interventional · 30 enrolled · Tanta UniversityNCT07498387updated 2026-03-27
- Efficacy of Clonidine in Reducing Craving in Inpatients With Cocaine and Crack Use DisorderRecruiting · Phase 4 · Interventional · 36 enrolled · University of Sao Paulo General HospitalNCT07313371updated 2026-02-24
- Study of Antiepileptic Drug in Generalised Convulsive Status EpilepticusCompleted · Phase 3 · Interventional · 203 enrolled · Assistance Publique - Hôpitaux de ParisNCT01150331updated 2026-01-15
- Effect of Treatments on Pain and Quality of Life in Individual With Burning Mouth SyndromeRecruiting · Phase 4 · Interventional · 150 enrolled · Federal University of Minas GeraisNCT06040190updated 2025-12-24
- New Combination of Chemoimmunotherapy for Systemic B-cell Lymphoma With Central Nervous System InvolvementCompleted · Phase 2 · Interventional · 79 enrolled · International Extranodal Lymphoma Study Group (IELSG)NCT02329080updated 2025-07-08
- Bioequivalence Study of Clonazepam 2 Mg TabletsNot yet recruiting · Phase 4 · Interventional · 24 enrolled · Centro de Atencion e Investigacion MedicaNCT06834503updated 2025-03-10
- Enhancing Mobility and Mental Health in Dementia PatientsNot yet recruiting · Interventional · 6 enrolled · Oxleas NHS Foundation TrustNCT06611202updated 2024-09-24
- Determining Optimal Treatment Sequences in Anxious Depression (DOTS-AD)Recruiting · Phase 4 · Interventional · 84 enrolled · University of CincinnatiNCT04245748updated 2024-08-29
- Inflammatory Markers in Saliva of Patients With Burning Mouth SyndromeCompleted · Interventional · 20 enrolled · Universidad de MurciaNCT06217731updated 2024-07-31
Structural analogs
Ranked by 2D fingerprint (Tanimoto) similarity over PubChem structures. Structural proximity only — not a claim of therapeutic equivalence.
Frequently asked questions
- How does Clonazepam work?
- Mechanism-of-action class: GABA A Modulators.
- What is Clonazepam used for?
- According to FDA labeling, Clonazepam carries indications including: Seizure Disorders: Clonazepam tablets are useful alone or as an adjunct in the treatment of the Lennox-Gastaut syndrome (petit mal variant), akinetic, and myoclonic seizures. In patients with absence seizures (petit mal) who have failed to respond to succinimides, clonazepam tablets may be useful.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
- What class of drug is Clonazepam?
- Clonazepam is classified as Benzodiazepine derivatives, Benzodiazepine, GABA A Modulators, Increased GABA Activity.
- What are the brand names for Clonazepam?
- Clonazepam is marketed under brand names including Klonopin.
- What are the contraindications for Clonazepam?
- Clonazepam labeling lists contraindications including: Clonazepam tablets are contraindicated in patients with the following conditions: History of sensitivity to benzodiazepines Clinical or biochemical evidence of significant liver disease Acute narrow angle glaucoma (it may be used in patients with open angle glaucoma who are receiving appropriate therapy).. Always consult the full prescribing information and a clinician.
clonazepam is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.