Alprazolam (Xanax) Dosing for Anxiety and Panic Disorders
For anxiety disorders, the recommended starting dose of alprazolam is 0.25 to 0.5 mg orally three times daily, with gradual increases as needed up to a maximum of 4 mg daily in divided doses. 1
Dosing Algorithm for Anxiety Disorders
Initial Dosing
- Standard adult starting dose: 0.25-0.5 mg orally three times daily
- Elderly patients or those with debilitating disease/advanced liver disease: 0.25 mg orally 2-3 times daily 2
Dose Titration
- Increase dose at intervals of 3-4 days
- Increase by no more than 0.5 mg per day
- Target the lowest effective dose that controls symptoms
- Maximum recommended daily dose: 4 mg in divided doses 1
Maintenance and Monitoring
- Distribute doses evenly throughout waking hours (three or four times daily)
- Reassess need for continued treatment frequently
- Monitor for side effects, particularly drowsiness
- Therapeutic plasma concentrations for anxiety: 20-40 ng/mL 3
Dosing Algorithm for Panic Disorder
Initial Dosing
- Starting dose: 0.5 mg orally three times daily 1
Dose Titration
- Increase at intervals of 3-4 days
- Increase by no more than 1 mg per day
- Slower titration recommended for doses above 4 mg daily
- Mean effective dose in clinical trials: 5-6 mg daily
- Maximum dose used in clinical trials: up to 10 mg daily 1
Maintenance and Monitoring
- For doses above 4 mg daily, periodic reassessment is advised
- Studies show patients on higher doses can often be tapered to 50% of maintenance dose without loss of benefit
- Therapeutic plasma concentrations for panic disorder: >20 ng/mL for remission of spontaneous panic attacks 3
Special Populations
Elderly Patients
- Starting dose: 0.25 mg orally 2-3 times daily 2
- Elderly patients are especially sensitive to benzodiazepine effects
- Monitor closely for excessive sedation, cognitive impairment, and fall risk
Patients with Hepatic Impairment
- Use lower starting doses
- Clearance is significantly reduced in patients with cirrhosis 4
- Monitor more frequently for side effects
Discontinuation
- Never discontinue alprazolam abruptly due to withdrawal risk
- Reduce dose gradually when discontinuing therapy
- Recommended tapering: decrease by no more than 0.5 mg every 3 days
- Some patients may require even slower tapering 1
Important Considerations
- Alprazolam reaches peak serum levels in 0.7-2.1 hours
- Half-life is approximately 12-15 hours 5
- Main side effect is drowsiness, though less than with diazepam at comparable doses
- Risk of dependence increases with dose and duration of treatment
- Alprazolam has shown effectiveness for panic disorder with complete remission of panic attacks in 85% of patients within an average of 6 days at a mean dose of 2.2 mg/day 6
Alprazolam is an effective medication for both anxiety and panic disorders when dosed appropriately, but careful attention must be paid to proper dosing, monitoring, and discontinuation to minimize risks while maximizing therapeutic benefit.