Alprazolam (Xanax)
Alprazolam is a short- to intermediate-acting triazolobenzodiazepine licensed for anxiety and panic disorder. Its rapid onset and high potency make it effective but also give it one of the higher dependence and misuse liabilities among benzodiazepines.
01 Overview
Alprazolam potentiates GABA at the GABA-A receptor, producing rapid anxiolysis that is particularly effective in panic disorder. Its relatively short half-life and quick onset contribute to a pronounced reinforcing effect and inter-dose rebound anxiety.
Dependence can develop quickly, and withdrawal from alprazolam is often described as more abrupt and severe than with longer-acting agents, including a seizure risk on abrupt cessation. Co-use with opioids or alcohol produces dangerous additive respiratory depression.
02 Mechanism
Positive allosteric modulator of the GABA-A receptor with high potency; enhances GABAergic inhibition to produce anxiolytic and sedative effects.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 0.25–0.5 mg | Oral | Typical starting dose for anxiety. |
| Common | 0.5–1 mg | Oral | Common per-dose range. |
| Therapeutic (daily) | 0.75–4 mg/day | Oral | Panic disorder may use higher divided daily totals under supervision. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| AnxiolysisRapid relief of anxiety and panic symptoms. | Onset ~20-40 min | Clinical | |
| Panic attack suppressionEffective at aborting and preventing panic attacks. | Clinical | ||
| SedationDose-dependent drowsiness and calm. | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Dependence and withdrawalRapid onset of tolerance and dependence; withdrawal can be abrupt and severe including seizures. | Severe | Common with regular use | Clinical | |
| Respiratory depressionAdditive respiratory and CNS depression with opioids or alcohol. | Life-threatening | Uncommon alone, higher with CNS depressants | Clinical | |
| Anterograde amnesia and cognitive impairmentMemory impairment, sedation and psychomotor slowing. | Moderate | Common | Clinical |