Equivalent Clonazepam Dose to Lorazepam 0.5 mg
The equivalent dose of clonazepam for lorazepam 0.5 mg is clonazepam 0.25 mg, based on the standard 2:1 conversion ratio (lorazepam:clonazepam). 1
Standard Conversion Ratio
- Clonazepam 0.25 mg is equivalent to lorazepam 0.5 mg, using the established 2:1 conversion ratio supported by the American Academy of Pediatrics 1
- This conversion applies most reliably for anxiolysis, sedation, and acute agitation management 1
Critical Pharmacokinetic Differences to Consider
- Clonazepam has a dramatically longer half-life (30-40 hours) compared to lorazepam, which affects dosing frequency and creates higher risk for drug accumulation 1
- Lorazepam has a faster onset of action with peak effect at 3-5 minutes IV, while clonazepam takes longer to reach peak effect 1
- Lorazepam is directly conjugated and eliminated without active metabolites, whereas clonazepam undergoes different metabolic pathways 1
Practical Dosing Adjustments
- Reduce the calculated equivalent dose by 25-50% initially when switching from lorazepam to clonazepam to account for clonazepam's longer half-life and accumulation risk 2
- For your specific case: start with clonazepam 0.125-0.1875 mg rather than the full 0.25 mg equivalent, then titrate based on clinical response 2
- Women may require higher doses than men to achieve the same clinical effect 1
Common Pitfalls and Safety Considerations
- Morning sedation, early morning motor incoordination, confusion, memory dysfunction, and increased fall risk are more pronounced with clonazepam than lorazepam due to the longer half-life 1
- Use clonazepam with particular caution in patients with neurodegenerative disorders, obstructive sleep apnea, or underlying liver disease 1
- Both medications can cause respiratory depression, especially when combined with opioids or other CNS depressants, requiring oxygen saturation monitoring 1
- In older adults, start at even lower doses (0.125 mg or less) due to higher risk of falls, confusion, and cognitive impairment 2