Lorazepam to Diazepam Conversion
Lorazepam 1 mg three times daily (3 mg total daily dose) converts to diazepam 15 mg total daily dose, typically divided as 5 mg three times daily.
Standard Conversion Ratio
The established equivalency is diazepam 10 mg = lorazepam 2-2.5 mg, meaning lorazepam is approximately 5 times more potent than diazepam 1. Using the conservative conversion factor:
- Lorazepam 1 mg = Diazepam 5 mg
- Total daily: Lorazepam 3 mg = Diazepam 15 mg 1
Dosing Schedule Recommendation
Divide the 15 mg diazepam dose into three times daily (5 mg TID) to match the original lorazepam dosing frequency 1. This maintains similar coverage throughout the day, though diazepam's longer half-life (20-100 hours with active metabolites) provides more sustained effects compared to lorazepam's 8-25 hour half-life 2, 3.
Critical Safety Considerations When Converting
Diazepam carries higher risks than lorazepam in specific contexts:
- Accumulation risk: Diazepam accumulates in peripheral tissues and produces active metabolites that persist, especially in patients with renal insufficiency 2
- Respiratory depression: Higher risk when combined with opioids or in patients with baseline respiratory insufficiency 2
- Elderly patients: Require 50% dose reduction (start with 2.5 mg BID maximum, not 5 mg TID) due to significantly increased sensitivity and decreased clearance with age 2
Monitoring Parameters After Conversion
Assess within 2 hours of initial dosing and daily thereafter 2:
- Level of sedation and cognitive function
- Blood pressure and heart rate
- Breakthrough anxiety symptoms or oversedation
- Paradoxical agitation (occurs in ~10% of patients) 4, 2
Important Clinical Caveats
Do not exceed maximum recommended doses: The standard lorazepam maximum is 4 mg/24 hours (2 mg/24 hours in elderly), so converting to diazepam should maintain equivalent safety margins 4. Titrate by 10-20% based on clinical response rather than using rigid conversion ratios 2.
Long-term use concerns: Regular benzodiazepine use leads to tolerance, addiction, depression, and cognitive impairment—use the lowest effective dose for the shortest duration 4, 2.