Valium (Diazepam) Dose Equivalent to Ativan (Lorazepam) 2mg
Diazepam 10 mg is equivalent to lorazepam 2 mg for sedation purposes. 1
Standard Conversion Ratio
- The established conversion is 5:1 (diazepam:lorazepam), meaning 10 mg of diazepam provides comparable sedative effects to 2 mg of lorazepam 1
- This equivalency has been validated across multiple clinical contexts including surgical premedication, where both 10 mg diazepam and 2 mg lorazepam demonstrated similar anxiolysis, sedation, and patient acceptance 2
Key Pharmacokinetic Differences
Onset and Duration:
- Diazepam has a faster onset of action (2-5 minutes IV) with peak clinical effect at 2-3 minutes, then effects diminish 3, 2
- Lorazepam has a slower onset (15-20 minutes IV) with a latent period of 8-15 minutes, but effects increase and persist longer at 15-30 minutes 3, 2
- Diazepam's duration of action is significantly longer (20-120 hours) due to active metabolites, compared to lorazepam's 8-15 hours 3
Metabolism Considerations:
- Diazepam produces active metabolites that accumulate in renal failure, prolonging sedation unpredictably 3
- Lorazepam undergoes glucuronide conjugation without active metabolites, making it safer in hepatic and renal dysfunction 3
- Both drugs require dose reduction in elderly patients, but diazepam's active metabolites make dosing adjustments more complex 3
Clinical Application Algorithm
Choose Diazepam 10 mg when:
- Rapid onset is critical (emergency agitation control) 3
- Single-dose administration is planned 1
- Patient has normal renal and hepatic function 3
Choose Lorazepam 2 mg when:
- Hepatic or renal impairment is present 3
- Prolonged, predictable sedation is desired 1
- Repeated dosing may be necessary 3
- IV access is limited (lorazepam absorbs better IM than diazepam) 1
Critical Dosing Adjustments
For elderly or debilitated patients:
- Reduce diazepam dose by 50% or more (start with 5 mg instead of 10 mg) 3
- Reduce lorazepam dose by 20% or more (start with 1.5 mg instead of 2 mg) 3
When combined with opioids:
- Both medications require dose reduction due to synergistic respiratory depression 3
- The combination produces more profound cardiopulmonary depression than either agent alone 3
Common Pitfalls to Avoid
- Do not assume equivalent duration: While 10 mg diazepam equals 2 mg lorazepam for initial sedation intensity, diazepam's effects last much longer due to active metabolites 3, 1
- Avoid diazepam in renal failure: Active metabolites accumulate unpredictably, causing prolonged sedation 3
- Do not use standard doses in liver disease: Both require reduction, but lorazepam is preferred due to simpler metabolism 3
- Watch for propylene glycol toxicity with lorazepam: Prolonged IV lorazepam infusions can cause metabolic acidosis and acute kidney injury 3