Section 10 · Monograph

Clonazepam

Reviewed Nov 2026FDA label
KlonopinBenzodiazepine
Forms
Tab: 0.5, 1, 2mg | ODT: 0.125-2mg
Dose
0.5-2mg qHS (REM behavior disorder)
MOA
↑GABA-A Cl- channel frequency

Black Box Warning

  • Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death
  • The use of benzodiazepines, including clonazepam, exposes users to risks of abuse, misuse, and addiction, which can lead to overdose or death
  • Abrupt discontinuation or rapid dosage reduction of clonazepam after continued use may precipitate acute withdrawal reactions, which can be life-threatening

Indications

  • Seizure disorders: Lennox-Gastaut syndrome, akinetic seizures, and myoclonic seizures; also used for absence (petit mal) seizures unresponsive to succinimidesFDA-labeled
  • Panic disorder, with or without agoraphobia, in adultsFDA-labeled

Off-Label Uses

  • REM sleep behavior disorder (RBD) — a parasomnia where patients act out dreams due to loss of normal REM-related muscle atonia, often an early marker of synucleinopathies (Parkinson's disease, dementia with Lewy bodies, multiple system atrophy). Typical off-label RBD dosing is low, 0.25-1 mg at bedtime, well below seizure/anxiety doses, aiming to suppress motor dyscontrol during REM via GABA-A enhancement. Melatonin (3-12 mg at bedtime) is often tried first or concurrently in RBD given a more favorable side-effect profile in the older, neurodegenerative-disease-prone population typically affected.Off-label

Mechanism of Action

  • A 1,4-benzodiazepine that enhances GABA-A receptor-mediated chloride conductance, potentiating the inhibitory effects of GABA, the principal inhibitory neurotransmitter in the CNS
  • This broad enhancement of inhibitory tone raises seizure threshold and produces anxiolytic/sedative effects

Full Dosing

Adult / usual

  • Seizure disorders (adults): initial 1.5mg/day in 3 divided doses; increase by 0.5-1mg every 3 days until seizures are controlled; maximum 20mg/day
  • Panic disorder (adults): initial 0.25mg twice daily; increase to a target dose of 1mg/day after 3 days; some patients may require up to 4mg/day
  • Taper gradually when discontinuing to reduce risk of withdrawal seizures
  • Schedule IV controlled substance (CIV)

Contraindications

  • Hypersensitivity to benzodiazepines
  • Significant liver disease
  • Acute narrow-angle glaucoma

Drug Interactions

  • Opioids: additive respiratory depression — boxed warning; avoid unless no alternative, use lowest effective doses
  • CYP3A4 inducers (phenytoin, carbamazepine, phenobarbital) can decrease clonazepam levels by roughly a third
  • CYP3A4 inhibitors (e.g., fluconazole) may increase clonazepam concentrations
  • Additive CNS depression with alcohol, other benzodiazepines, barbiturates, antipsychotics, and other sedatives
  • Valproate combined with clonazepam has rarely been associated with absence status

Adverse Effects

  • Common: somnolence, depression, ataxia/coordination abnormalities, dizziness
  • Respiratory depression, particularly with concomitant opioids/CNS depressants
  • Paradoxical reactions: agitation, irritability, aggressive behavior
  • Cognitive/memory impairment with chronic use
  • Withdrawal seizures or symptoms on abrupt discontinuation
  • Suicidal ideation/behavior (class effect of ASMs)
  • Tolerance and physical/psychological dependence with prolonged use

Monitoring Parameters

  • Periodic blood counts and liver function tests with long-term therapy
  • Monitor for suicidal thoughts/behavior
  • Assess risk for abuse/misuse/dependence before and during treatment
  • Monitor respiratory status and sedation level, especially if combined with opioids or other CNS depressants
  • Watch for withdrawal symptoms when tapering or discontinuing

Pregnancy & Lactation

  • Human data on teratogenicity risk are inconclusive; animal studies have shown malformations at various doses
  • Encourage enrollment in the North American Antiepileptic Drug (NAAED) Pregnancy Registry (1-888-233-2334)
  • Use late in pregnancy may be associated with neonatal sedation and withdrawal symptoms
  • Effects on breastfed infants and milk production are unknown; monitor infant for sedation and poor feeding if used during lactation

References

  1. KLONOPIN (clonazepam) Prescribing Information — FDA accessdata.fda.gov

Same class

Please visitfamilydeckofcards.com