Diazepam Equivalent of Alprazolam 4mg
The diazepam equivalent of alprazolam 4mg is approximately 40mg of diazepam, using the standard 1:10 conversion ratio.
Benzodiazepine Equivalency Conversion
The conversion between alprazolam and diazepam is based on their relative potencies for anxiolytic and hypnosedative effects:
- Standard conversion ratio: 1mg alprazolam = 10mg diazepam 1, 2
- Therefore, 4mg alprazolam = 40mg diazepam
Evidence Supporting This Conversion
Clinical studies have consistently demonstrated this equivalency:
- A controlled study in benzodiazepine-dependent patients found that 0.5mg alprazolam was equivalent to 5mg diazepam when testing hypnosedative and anxiolytic properties, confirming the 1:10 ratio 1
- Multiple comparative trials used average daily doses of approximately 1.5mg alprazolam versus 18.6mg diazepam (roughly 1:12 ratio) and found equivalent anxiolytic efficacy 2
- Another double-blind comparison found 1.5-3mg alprazolam/day equivalent to 15-30mg diazepam/day for anxiolytic effect 3
- A panic disorder trial demonstrated equal efficacy between diazepam and alprazolam at flexible doses, supporting their interchangeability when properly converted 4
Important Clinical Considerations
Potency and Abuse Liability Differences
Alprazolam demonstrates somewhat higher reinforcing properties compared to diazepam, which may contribute to greater abuse liability in benzodiazepine-dependent patients 1. This is clinically relevant when converting patients from high-dose alprazolam (such as 4mg daily).
Pharmacokinetic Differences
- Alprazolam has a shorter half-life than diazepam, requiring more frequent dosing 5
- Diazepam has active metabolites (N-desmethyldiazepam) with prolonged elimination, providing longer duration of effect 5
- Detection times after high-dose use: diazepam up to 9 days, alprazolam up to 2.5 days in oral fluid 5
Conversion Cautions
When converting from alprazolam 4mg (a high dose) to diazepam:
- Start with the calculated equivalent (40mg diazepam) but be prepared to adjust based on clinical response
- Monitor closely for withdrawal symptoms during the first 48-72 hours, as alprazolam's shorter half-life may cause earlier withdrawal onset
- Consider dividing diazepam into 2-3 daily doses initially to match alprazolam's dosing pattern, then consolidate as tolerated
- Patients on chronic high-dose alprazolam may require slightly higher diazepam equivalents due to tolerance and cross-tolerance variations 1