What is the equivalent dose of Klonopin (clonazepam) for 8mg of Ativan (lorazepam)?

Benzodiazepine Dose Equivalency: Lorazepam to Clonazepam

8 mg of lorazepam (Ativan) is equivalent to approximately 4 mg of clonazepam (Klonopin) using the standard 2:1 conversion ratio. 1, 2

Standard Conversion Ratio

• The established conversion is 1 mg lorazepam = 0.5 mg clonazepam, meaning lorazepam is approximately twice as potent as clonazepam 1, 2
• To convert lorazepam to clonazepam: divide the lorazepam dose by 2 2
• For your specific question: 8 mg lorazepam ÷ 2 = 4 mg clonazepam 2

Critical Pharmacokinetic Differences

However, this simple conversion does not account for the dramatically different half-lives between these medications, which is clinically crucial:

• Clonazepam has a half-life of 30-40 hours compared to lorazepam's much shorter duration 2
• This means clonazepam provides sustained coverage over 24+ hours, while lorazepam requires dosing every 6-12 hours 2
• When switching from lorazepam to clonazepam, you should reduce the calculated equivalent dose by 50% to account for the longer half-life 2

Practical Conversion Algorithm

For converting 8 mg daily lorazepam to clonazepam:

1. Calculate basic equivalent: 8 mg lorazepam ÷ 2 = 4 mg clonazepam 2
2. Adjust for half-life difference: 4 mg ÷ 2 = 2 mg clonazepam daily 2
3. Divide into 1-2 doses per day (clonazepam's long half-life allows once or twice daily dosing) 2
4. Start with 1 mg twice daily or 2 mg once daily 2

Dosing Schedule Considerations

• Lorazepam at 8 mg/day is typically dosed as 2 mg four times daily (every 6 hours) 1
• The equivalent clonazepam dose of 2 mg can be given once or twice daily due to its extended half-life 2
• Monitor closely during the first 1-4 hours after clonazepam administration when peak plasma concentrations occur 2

Critical Monitoring and Titration

• Titrate the dose by 10-20% based on clinical response after initiating the conversion 2
• Monitor for breakthrough symptoms or oversedation during the transition 2
• Approximately 10% of patients experience paradoxical agitation with benzodiazepines 1, 2
• Monitor oxygen saturation, especially when combined with other CNS depressants 2

Common Pitfalls to Avoid

• Do not use the simple 1:2 ratio without adjusting for half-life differences - this will result in overdosing 2
• Never abruptly switch - consider a gradual taper and cross-titration if the patient has been on lorazepam chronically 3
• Be aware that tolerance develops with chronic benzodiazepine use, which may affect conversion calculations 4
• Clonazepam causes more prolonged sedation and amnesia compared to lorazepam 5

Special Population Adjustments

• For elderly or debilitated patients: start with 0.5-1 mg clonazepam twice daily maximum 2
• Consider starting with even lower equivalent doses (e.g., 0.5 mg clonazepam for 2 mg lorazepam) in hepatic impairment 2