IV Equivalent Dose of Ativan (Lorazepam) to Valium (Diazepam)

The intravenous (IV) equivalent dose of Ativan (lorazepam) to Valium (diazepam) is approximately 1 mg lorazepam to 5 mg diazepam. 1, 2

Pharmacological Basis for Conversion

Lorazepam and diazepam differ significantly in their pharmacokinetic properties, which explains their dosing equivalence:

Potency: Lorazepam is approximately 5 times more potent than diazepam when administered intravenously 2
Onset of Action:
- Lorazepam IV: 1-5 minutes
- Diazepam IV: 2-3 minutes 1, 3
Duration of Effect:
- Lorazepam IV: 60-120 minutes
- Diazepam IV: 20-30 minutes 1, 4

Lorazepam 4 mg IV (given at 2 mg/min) is the standard dose for status epilepticus in adults 5
Diazepam dose for status epilepticus is typically 10-20 mg IV 6
Lorazepam has a significant advantage over diazepam in status epilepticus due to its longer duration of action (several hours vs. 20-30 minutes) 4

For sedation and anxiety relief, lorazepam 2 mg IV is approximately equivalent to diazepam 10 mg IV 2
Standard initial dose for sedation with lorazepam is 2 mg IV total or 0.02 mg/lb (0.044 mg/kg) 5

Elderly patients (>60 years) require dose reduction of 20% or more due to increased sensitivity to benzodiazepine effects 1
No specific dosage adjustments are needed for lorazepam in elderly patients with normal hepatic function 5

No dosage adjustments are needed for lorazepam in patients with hepatic disease 5
For acute administration, no adjustment is needed for patients with renal disease, but caution should be exercised if frequent doses are given over short periods 5

Lorazepam clearance is reduced by 80% in neonates compared to adults 5
Children and adolescents have a 50% higher volume of distribution (normalized to body weight) compared to adults 5

Respiratory Depression: Both medications can cause respiratory depression, especially when combined with other sedatives or opioids. Monitor oxygen saturation and respiratory effort closely 6, 5
Drug Interactions: Reduce lorazepam dose by 50% when coadministered with probenecid or valproate 5
Administration Rate: Administer lorazepam IV at a rate not exceeding 2 mg per minute to minimize adverse effects 5
Venous Complications: Lorazepam IV administration is associated with a lower frequency of venous thrombosis compared to diazepam 2
Dilution Requirements: Lorazepam must be diluted with an equal volume of compatible solution (Sterile Water for Injection, Sodium Chloride Injection, or 5% Dextrose Injection) immediately prior to IV use 5