What is the equivalent dose of Valium (diazepam) to 1mg three times a day (TID) alprazolam and what is a recommended starting dose for transitioning?

Transitioning from Alprazolam to Diazepam (Valium)

Equivalent Dose Conversion

For a patient taking alprazolam 1mg TID (total 3mg/day), the equivalent diazepam starting dose is 15mg/day, typically divided as 5mg TID. This conversion is based on the standard benzodiazepine equivalency ratio where 1mg alprazolam equals approximately 5mg diazepam 1.

Rationale for Transitioning to Diazepam

Diazepam is preferred for benzodiazepine tapering due to its longer half-life compared to alprazolam, which reduces the severity of withdrawal symptoms and interdose rebound anxiety 1. Alprazolam has a half-life of 9-16 hours 2, while diazepam has a significantly longer duration of action, making the transition smoother and withdrawal more manageable 1.

Starting Dose Recommendation

• Initial conversion: Start with diazepam 15mg/day divided into three doses (5mg TID) 1
• Timing: Administer doses at the same intervals the patient was taking alprazolam to maintain steady coverage 1
• Monitoring period: Observe for 3-5 days at this equivalent dose before beginning any taper to ensure adequate symptom control 1

Important Caveats

Dose Adjustments for Special Populations

• Elderly or debilitated patients: Reduce the starting diazepam dose by 50% (start with 7.5mg/day total) due to reduced clearance and increased sensitivity 1
• Hepatic impairment: Diazepam clearance is significantly reduced in cirrhosis; consider starting at lower doses 2
• Renal disease: While primarily hepatically metabolized, monitor closely as protein binding may be affected 2

Critical Warnings

• Avoid abrupt substitution: Some clinicians prefer a gradual cross-taper, reducing alprazolam by 25% while introducing diazepam, though direct substitution at equivalent doses is also acceptable 1
• Tolerance and dependence: Regular benzodiazepine use leads to tolerance, addiction, depression, and cognitive impairment; the goal should be eventual discontinuation 1
• Paradoxical reactions: Approximately 10% of patients experience paradoxical agitation with benzodiazepines 1
• Respiratory depression risk: Both agents can cause respiratory depression, particularly when combined with other CNS depressants or in patients with underlying respiratory disease 1

Drug Interactions

• Nefazodone: If the patient is taking nefazodone, reduce the alprazolam dose by 50% during transition, as this interaction may carry over to diazepam 1
• Avoid alcohol and other CNS depressants: Additive effects significantly increase sedation and respiratory depression risk 1

Monitoring After Transition

• Assess symptom control within 3-5 days to determine if the equivalent dose is adequate 1
• Watch for oversedation: Peak effects of diazepam occur later than alprazolam, so cumulative sedation may develop 1, 3
• Document withdrawal symptoms: Anxiety, insomnia, tremor, or autonomic instability suggest inadequate dosing 1