Clonazepam


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Epilepsy Initial: 1 mg at night for 4 days, gradually increased over 2-4 wk. Maintenance: 4-8 mg/day. Max: 20 mg/day. Panic disorder Initial: 0.25 mg bid, increased after 3 days up to 1 mg/day. Max: 4 mg/day. IV Emergency treatment of status epilepticus 1 mg via slow IV inj or infusion over at least 2 minutes, repeated if necessary. Max: 10 mg.
Dosage Details
Intravenous
Emergency management of status epilepticus
Adult: 1 mg via slow IV inj or infusion over at least 2 minutes, repeated if necessary. Max: 10 mg.
Child: 500 mcg by slow IV inj over at least 2 minutes or by infusion.

Oral
Panic disorder
Adult: Initially, 0.25 mg bid, increased after 3 days up to 1 mg/day. Max: 4 mg/day.

Oral
Epilepsy
Adult: Initially, 1 mg given at night for 4 days, gradually increased over 2-4 wk. Maintenance: 4-8 mg/day. Max: 20 mg/day.
Child: ≤10 yr or ≤30 kg: Initially, 0.01-0.03 mg/kg/day but not to exceed 0.05 mg/kg/day given in 2 or 3 divided doses. May be increased by no more than 0.25-0.5 mg every 3rd day until seizure control is achieved. Maintenance: 0.1-0.2 mg/kg/day divided 3 times daily. Max: 0.2 mg/kg/day.
Elderly: Initially, 0.5 mg at night for 4 days.
Hepatic Impairment
Dosage adjustment may be needed.
Administration
May be taken with or without food.
Contraindications
Patient w/ acute angle closure glaucoma, acute pulmonary insufficiency, severe resp insufficiency, myasthenia gravis, sleep apnoea syndrome.
Special Precautions
Patient w/ open angle glaucoma, chronic pulmonary insufficiency, porphyria, spinal or cerebellar ataxia, history of alcohol or drug addiction, and depression and/or suicide attempts. Increased risk of suicidal behaviour and ideation. Avoid abrupt withdrawal. Renal and hepatic impairment. Elderly or debilitated patient. Pregnancy and lactation.
Adverse Reactions
Drowsiness or sedation, fatigue, muscular hypotonia, behavioural disturbances including aggressiveness, agitation, hyperkinesis and irritability; coordination disturbances, dizziness, vertigo, anorexia, visual disturbances, libido changes; rhinorrhoea, chest congestion and shortness of breath; skin rash, hair loss, hirsutism, and ankle and facial oedema; diarrhoea, constipation, wt gain or loss, abnormal thirst, encopresis, gastritis, increased or decreased appetite, dyspepsia, nausea, coated tongue, dry mouth, sore gums; nocturia, dysuria, enuresis, urinary retention. Salivary or bronchial hypersecretion leading to resp problems (childn). Rarely, abnormal skin pigmentation.
Patient Counseling Information
May impair ability to drive or operate machinery.
MonitoringParameters
Monitor signs of suicidal ideation, resp depression and BP.
Overdosage
Symptoms: Somnolence, confusion, ataxia, diminished reflexes or coma. Management: Supportive and symptomatic treatment. Flumazenil may be used for the complete or partial reversal of the sedative effects but there is a risk of seizure esp in long-term benzodiazepine users and in cyclic antidepressant overdose. Induce emesis or perform gastric lavage followed by activated charcoal and saline cathartic to remove any remaining drug. Hypotension may be treated w/ IV norepinephrine or metaraminol.
Drug Interactions
Additive depressant effect w/ TCAs, MAOIs, sedative and hypnotics, barbiturates, anxiolytics, antipsychotics, opiate agonists. May increase serum phenytoin levels.
Food Interaction
Additive CNS depression when administered concomitantly w/ alcohol-containing preparation and beverages.
Action
Description: Clonazepam reduces the nerve transmission in the motor cortex which suppresses the spike and wave discharge in absence seizures. Its mechanism is believed to be related to its ability to enhance the activity of GABA. Clinically, it improves focal epilepsy and generalised seizures.
Onset: Approx 20-40 min.
Duration: 6-8 hr (adult); ≤12 hr (infant and childn).
Pharmacokinetics:
Absorption: Immediately and completely absorbed from the GI tract. Bioavailability: Approx 90%. Time to peak plasma concentration: 1-4 hr.
Distribution: Crosses the placenta and enters breast milk. Volume of distribution: 1.5-3 L/kg (childn); 1.5-64.4 L/kg (adult). Plasma protein binding: Approx 85%.
Metabolism: Extensive hepatic metabolism via glucuronide and sulfate conjugation; converted to 7-aminoclonazepam (major metabolite), and 7-acetamido- and 3-hydroxy-derivatives (minor metabolites).
Excretion: Via urine as free or conjugated metabolites. Elimination half-life: Approx 20-40 hr.
Storage
Store at 25°C.
References
Anon. Clonazepam. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 16/04/2014.

Buckingham R (ed). Clonazepam. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 16/04/2014.

Clonazepam Tablet (Watsons Lab., Inc). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed/. Accessed 16/04/2014.

Joint Formulary Committee. Clonazepam. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 16/04/2014.

Klonopin Tablets and Orally Disintegrating Tablets. U.S. FDA. https://www.fda.gov/. Accessed 16/04/2014.

McEvoy GK, Snow EK, Miller J et al (eds). Clonazepam. AHFS Drug Information (AHFS DI) [online]. American Society of Health-System Pharmacists (ASHP). https://www.medicinescomplete.com. Accessed 16/04/2014.

Disclaimer: This information is independently developed by MIMS based on Clonazepam from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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