Alprazolam: Difference between revisions

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{{MedTemplate

| generic = ~~alprazolam~~

| generic = Alprazolam

| brand = Xanax, Niravam

| brand = Xanax, Xanax XR, Niravam, Frontin, Alprax, Helex

| structure =

| structure = Alprazolam_structure.svg

| ~~class~~ = ~~Benzodiazepines~~, ~~Anxiolytics~~

| classes = Benzodiazepine, Anxiolytic

| mechanism = GABA-A ~~allosteric modulation~~

| mechanism = Positive allosteric modulator at GABAA receptor (benzodiazepine site)

| uses = ~~Anxiety~~, ~~Panic~~, ~~Psychedelic crisis~~

| uses = Generalized anxiety disorder, panic disorder, anxiety with depression

| formula =

| formula = C17H13ClN4

~~| mass =~~

| routes = Oral, sublingual (ODT)

~~| cas =~~

| onset = 15–30 minutes

~~| atc =~~

| duration = 4–6 hours (IR); 11–17 hours (XR)

| routes =

| halflife = ~11 hours (range 6–27 h; prolonged in elderly and hepatic impairment)

| onset =

| bioavailability = ~80–100%

| duration =

| pregnancy = Avoid

| halflife =

| legal = Schedule IV

| bioavailability =

| intro = '''Alprazolam''' is a high-potency, intermediate-acting triazolobenzodiazepine, FDA-approved for generalized anxiety disorder, panic disorder, and anxiety associated with depression. Its rapid onset, short-to-intermediate half-life, and high potency make it both clinically effective and uniquely problematic among benzodiazepines: alprazolam has consistently been associated with the highest rates of dependence, misuse, and difficult withdrawal in its class. For most chronic anxiety treatment, longer-acting agents (clonazepam, diazepam) or non-benzodiazepine alternatives (SSRIs, SNRIs, buspirone) are preferred.

| pregnancy =

| pharmacokinetics = Rapid and near-complete oral absorption; bioavailability ~80–100%. Peak plasma levels in 1–2 hours (IR) or ~9 hours (XR). Highly protein-bound (~80%). Metabolized hepatically by '''CYP3A4''' to α-hydroxyalprazolam and 4-hydroxyalprazolam — both pharmacologically active but present at low concentrations. Half-life ~11 hours in healthy adults; substantially prolonged in elderly patients, obesity, and hepatic impairment. The relatively short half-life relative to diazepam contributes to inter-dose rebound anxiety with TID dosing and to the severity of its discontinuation syndrome.

| legal =

| pharmacodynamics = Binds to the benzodiazepine site on GABAA receptors, allosterically enhancing GABA-induced chloride channel opening (increased '''frequency''' of opening, not duration — distinguishing benzodiazepines from barbiturates). This hyperpolarizes the neuron, producing anxiolytic, sedative, hypnotic, anticonvulsant, and skeletal muscle relaxant effects. Compared to other benzodiazepines, alprazolam shows relatively greater anxiolytic and antipanic effect with somewhat less sedation per unit anxiolysis, attributed in part to its triazole ring. Some evidence of mild antidepressant activity at higher doses, the basis for its "anxiety with depression" indication.

| intro =

| indications = * Generalized anxiety disorder

| ~~pharmacology~~ =

* Panic disorder (with or without agoraphobia)

| ~~pharmacokinetics~~ =

* Anxiety associated with depression

| indications =

* '''Not first-line''' for chronic anxiety — SSRIs, SNRIs, buspirone, or CBT typically preferred due to dependence risk

| dosing =

* Occasionally used short-term for procedural anxiety or situational anxiety

| effects =

| dosing = '''GAD:''' Start 0.25–0.5 mg PO three times daily; titrate slowly. Max 4 mg/day.

| adverse =

'''Panic disorder:''' Start 0.5 mg PO three times daily; titrate by 1 mg/day every 3–4 days. Typical effective 1–10 mg/day (FDA labeling permits to 10 mg/day, but doses >4 mg substantially increase dependence and adverse effects).

| contraindications =

'''Elderly/debilitated:''' Start 0.25 mg 2–3 times daily; titrate very cautiously.

| interactions =

'''Hepatic impairment:''' Reduce dose 50% or more.

| pregnancy_details =

'''Discontinuation:''' '''Always taper.''' Typical reduction 0.5 mg every 3 days at minimum; for long-term users, much slower (Ashton-style protocols reduce by ~10% of current dose every 1–2 weeks). Abrupt cessation can precipitate seizures.

| monitoring =

| effects = ''Therapeutic:'' anxiolysis (rapid), reduced panic frequency and severity, calming, mild euphoria, improved sleep.

| counseling =

''Common adverse:'' '''drowsiness''', '''dizziness''', impaired coordination, fatigue, slurred speech, dry mouth, blurred vision, '''anterograde amnesia''', impaired psychomotor performance, decreased libido, changes in appetite.

| adverse = * '''Dependence and addiction''' — highest among commonly-prescribed benzodiazepines. Physical dependence can develop within weeks of regular use.

* '''Withdrawal syndrome''' — rebound anxiety, insomnia, tremor, sweating, perceptual disturbances, depersonalization, '''seizures''' with abrupt cessation. Often more severe and protracted than withdrawal from longer-acting benzodiazepines.

* '''Tolerance''' — anxiolytic and hypnotic tolerance develops with chronic use; tolerance to amnestic and motor effects is less complete.

* '''Respiratory depression''' — especially in combination with opioids ('''black box warning'''), alcohol, or other CNS depressants. Cause of many overdose deaths.

* '''Paradoxical reactions''' — agitation, disinhibition, aggression, particularly in elderly, children, or those with personality disorders.

* '''Cognitive impairment''' — both acute (memory, attention) and chronic with long-term use; partial reversibility uncertain.

* '''Falls and fractures''' in elderly.

* '''Anterograde amnesia''' — clinically significant; can be exploited for criminal purposes (drug-facilitated assault).

* '''Misuse and diversion''' — Xanax has substantial street value and frequent recreational misuse.

* '''Suicide risk in overdose''' — especially when combined with alcohol or opioids.

* '''Rebound anxiety''' between doses with short-half-life IR formulation.

| contraindications = * Acute narrow-angle glaucoma

* Severe respiratory insufficiency (including untreated sleep apnea)

* Severe hepatic impairment

* Concurrent strong CYP3A4 inhibitors (ketoconazole, itraconazole) — contraindicated per FDA labeling

* Known hypersensitivity to alprazolam or benzodiazepines

* Caution: history of substance use disorder, myasthenia gravis, pregnancy

| interactions = * '''Opioids''' — additive respiratory depression and overdose risk ('''FDA black box warning'''); avoid when possible

* '''Alcohol''' — additive CNS depression and respiratory depression

* '''CYP3A4 inhibitors''' (ketoconazole, itraconazole, ritonavir, clarithromycin, nefazodone) — substantially increase alprazolam levels; some contraindicated

* '''CYP3A4 inducers''' (carbamazepine, phenytoin, rifampin, St. John's wort) — decrease levels; may reduce efficacy

* '''Other CNS depressants''' (Z-drugs, sedating antihistamines, gabapentinoids, sedating antidepressants) — additive

* '''Grapefruit juice''' — modest CYP3A4 inhibition; can raise alprazolam levels with regular consumption

* '''Fluoxetine, fluvoxamine''' — increase alprazolam levels via CYP3A4 inhibition

| pregnancy_details = Historically Category D. First-trimester benzodiazepine exposure has been associated with increased risk of cleft lip/palate in some studies, though absolute risk is small. Third-trimester or near-term use can produce '''floppy infant syndrome''' (hypotonia, hypothermia, feeding difficulty, respiratory depression) and neonatal withdrawal. Generally avoided in pregnancy unless benefits clearly outweigh risks; SSRIs are usually preferred for chronic anxiety. Excreted in breast milk — breastfeeding generally discouraged.

| monitoring = * Continued need for treatment — reassess at every visit; target shortest effective duration

* Signs of dependence, tolerance, dose escalation, or misuse

* Cognitive function, especially in long-term users and elderly

* Mood and suicidality

* Falls risk in elderly

* Respiratory status, especially in COPD/OSA or on opioids

* Liver function in long-term use

| counseling = * '''Take exactly as prescribed''' — do not increase dose without consulting prescriber.

* '''Do not combine with alcohol''' or other sedatives — combinations can be fatal.

* '''Do not stop abruptly''' — can cause seizures; must be tapered.

* Avoid driving or operating machinery until response is known.

* May cause memory gaps, especially with higher doses or alcohol.

* Long-term daily use carries a real risk of dependence — discuss alternatives if treatment will extend beyond a few weeks.

* Avoid grapefruit juice in large quantities.

* Keep secured — high risk of theft and diversion.

* If pregnant or planning pregnancy, discuss with prescriber.

| anecdotes =

| seealso =

| seealso = [[Lorazepam]], [[Diazepam]], [[Clonazepam]], [[Temazepam]], [[Midazolam]], [[Buspirone]], [[Hydroxyzine]], [[Pregabalin]]

| references =

}}

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