alprazolam (Xanax, Niravam)
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Introduction
Tradename: Xanax. DEA-controlled substance: class 4.
Indications
- treatment of anxiety, including generalized anxiety disorder
- short-term management of panic attacks
- treatment of depression, including major depression
- treatment of essential tremor
- NOT for sleeping disorders
- NOT for management of anxieties or stresses of everyday life
Contraindications
- history of addiction
- severe, uncontrolled pain
- narrow-angle glaucoma
- severe respiratory depression
- pre-existing CNS depression Warning:
- elderly may need assistance with ambulation, especially early in therapy
Dosage
- 0.25-0.5 mg PO TID[1]
- 0.75-4.00 mg/24 hours divided TID[2]
- up to 4 mg/day (anxiety); 10 mg/day (panic attacks)
- may be taken with food
- avoid alcohol ingestion
- re-evaluate for treatment > 4 months duration
- taper when discontinuing after chronic use
Tabs: 0.25, 0.5, 1, 2 mg; Xanax XR (extended release)
Niravam: orally disintegrating tablets
Pharmacokinetics
- rapidly & completely absorbed after oral or sublingual administration
- peak plasma levels in 1-2 hours
- most plasma alprazolam is bound to albumin
- volume of distribution of 0.8 to 1.3 L/kg
- metabolized in the liver by cyt P450 3A4
- major pathway of metabolism is hydroxylation
- alpha hydroxyalprazolam is the major metabolite
- parent molecule & metabolites excreted in urine
- elimination half-life is 9-16 hours (1 mg dose)
- 1/2 life may be increased up to 20 hours in elderly
elimination via liver
elimination via kidney
1/2life = 11-15 hours
protein binding = 68-74 %
Adverse effects
- common (> 10%)[4]
- tachycardia, chest pain, drowsiness, fatigue, ataxia, lightheadedness, memory impairment, insomnia, anxiety, depression, headache, rash, decreased libido, dry mouth, constipation, decreased salivation, nausea/vomiting, diarrhea, dysarthria, blurred vision, sweating
- less common (1-10%)[4]
- other[3]
- drowsiness
- dizziness
- withdrawal: most prone of benzodiazepines to cause seizures during withdrawal
- agitation
- anterograde amnesia
- addiction
- hiccups
- drug adverse effects of benzodiazepines
- drug adverse effects of psychotropic agents
- drug adverse effects of sedatives
Drug interactions
- disulfiram, nefazodone, fluoxetine, cimetidine & grapefruit juice cause an increase in alprazolam levels
- CNS depressants: in combination increase CNS depression
- antiepileptic agents, rifampin: increase metabolism of alprazolam
- flumazenil (Romazicon): antagonizes affects of benzodiazepines
- any drug that inhibits cyt P450 3A4 may increase levels of alprazolam
- any drug that induces cyt P450 3A4 may diminish levels of alprazolam
- drug interaction(s) of methadone in combination with benzodiazepines
- drug interaction(s) of benzodiazepines with antidepressants
- drug interaction(s) of benzodiazepines with thiazide diuretics
- drug interaction(s) of antipsycotics with benzodiazepines
- drug interaction(s) of antidepressants with benzodiazepines
- drug interaction(s) of beta-adrenergic receptor antagonists with benzodiazepines
- drug interaction(s) of beta-adrenergic receptor antagonists (except atenolol) with benzodiazepines
- drug interaction(s) of alcoholic beverage with benzodiazepines
- drug interaction(s) of benzodiazepine with opiates
- drug interaction(s) of gabapentinoid with psychotropic agent
Mechanism of action
- triazolobenzodiazepine that potentiates GABA's inhibitory effects by increasing neuronal permeability to Cl-
More general terms
More specific terms
Additional terms
Component of
References
- ↑ Jump up to: 1.0 1.1 The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996.
- ↑ Jump up to: 2.0 2.1 Manual of Medical Therapeutics, 28th ed, Ewald & McKenzie (eds), Little, Brown & Co, Boston, 1995, pg 7
- ↑ Jump up to: 3.0 3.1 Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998
- ↑ Jump up to: 4.0 4.1 4.2 Kaiser Permanente Northern California Regional Drug Formulary, 1998
- ↑ Clinical Guide to Laboratory Tests, 3rd ed. Teitz ed., W.B. Saunders, 1995
- ↑ Prescriber's Letter 13(3): 2006 Cytochrome P450 drug interactions Detail-Document#: http://prescribersletter.com/(5bhgn1a4ni4cyp2tvybwfh55)/pl/ArticleDD.aspx?li=1&st=1&cs=&s=PRL&pt=3&fpt=25&dd=220233&pb=PRL (subscription needed) http://www.prescribersletter.com
- ↑ Wikipedia: Alprazolam http://en.wikipedia.org/wiki/Alprazolam
- ↑ Greenblatt DJ and Wight CE Clinical pharmakinetics of alprazolam, Therapeutic implications. Clin Pharmacokinet. 1993 Jun;24(6):453-71. PMID: https://www.ncbi.nlm.nih.gov/pubmed/8513649