What is the equivalent dose of Ativan (lorazepam) for a patient taking 10 mg of Klonopin (clonazepam)?

Equivalent Dose Conversion from Clonazepam (Klonopin) to Lorazepam (Ativan)

For a patient taking 10 mg of clonazepam (Klonopin), the equivalent dose of lorazepam (Ativan) is 5 mg.

Benzodiazepine Equivalence Ratios

The conversion between benzodiazepines follows established equivalence ratios based on clinical potency:

• Clonazepam 2 mg = Lorazepam 1 mg
• Therefore, clonazepam 10 mg = lorazepam 5 mg

This 2:1 ratio (clonazepam:lorazepam) is supported by clinical guidelines and reflects the relative potency of these medications 1.

Dosing Considerations

When converting between benzodiazepines, several important factors should be considered:

• Onset and duration of action: Clonazepam has a longer half-life (30-40 hours) compared to lorazepam (10-20 hours)
• Peak effect timing: Lorazepam reaches peak effect more quickly than clonazepam
• Cross-tolerance: Incomplete cross-tolerance between benzodiazepines may require dose adjustment

Implementation Strategy

When transitioning from clonazepam to lorazepam:

1. Initial conversion: Start with lorazepam 5 mg total daily dose
2. Dosing schedule: Divide the total daily dose into 2-3 administrations due to lorazepam's shorter duration of action
   • For example: 2 mg in the morning, 1 mg in the afternoon, and 2 mg at bedtime
3. Monitoring: Assess for withdrawal symptoms or over-sedation during the first 3-5 days after conversion
4. Dose adjustment: Titrate the lorazepam dose based on clinical response

Important Clinical Considerations

• Withdrawal risk: Due to clonazepam's longer half-life, patients may experience delayed withdrawal symptoms when switching to lorazepam
• Sedation monitoring: Watch for excessive sedation during the transition period
• Cognitive effects: Lorazepam may cause more pronounced cognitive impairment in some patients
• Dosing frequency: Lorazepam typically requires more frequent dosing than clonazepam due to its shorter duration of action

Common Pitfalls to Avoid

• Abrupt discontinuation: Never abruptly switch between benzodiazepines without a proper tapering schedule
• Underestimating equivalence: Using too low a dose of lorazepam may lead to withdrawal symptoms
• Overestimating equivalence: Using too high a dose may cause excessive sedation
• Ignoring individual factors: Age, liver function, and concomitant medications can affect benzodiazepine metabolism and required dosing

For patients with impaired liver function, elderly patients, or those on multiple medications, consider starting with a lower dose of lorazepam (approximately 3-4 mg total daily) and titrating upward as needed based on clinical response.