Alprazolam: Pharmacokinetics, Clinical Efficacy, and Mechanism of Action

Abstract

Alprazolam, a triazolobenzodiazepine, is the first of this new class of benzodiazepine drugs to be marketed in the United States and Canada. It achieves peak serum levels in 0.7 to 2.1 hours and has a serum half-life of 12 to 15 hours. When given in the recommended daily dosage of 0.5 to 4.0 mg, it is as effective as diazepam and chlordiazepoxide as an anxiolytic agent. Its currently approved indication is for the treatment of anxiety disorders and symptoms of anxiety, including anxiety associated with depression. Although currently not approved for the treatment of depressive disorders, studies published to date have demonstrated that alprazolam compares favorably with standard tricyclic antidepressants. Also undergoing investigation is the potential role of alprazolam in the treatment of panic disorders. Alprazolam has been used in elderly patients with beneficial results and a low frequency of adverse reactions. Its primary side effect, drowsiness, is less than that produced by diazepam at comparable doses. Data on toxicity, tolerance, and withdrawal profile are limited, but alprazolam seems to be at least comparable to other benzodiazepines. Drug interaction data are also limited, and care should be exercised when prescribing alprazolam for patients taking other psychotropic drugs because of potential additive depressant effects.

Comparison between alprazolam and hydroxyzine for oral premedication

“…6 However, previous studies have identified alprazolam as a potent antianxiety agent with a lower incidence of benzodiazepine pharmacology related side effects such as drowsiness and amnesia. 4,5 Safety evaluation of the premedicants was based upon the global assessment of tolerance by the patient, the frequency of reported adverse events and the evolution of vital signs during the trial. Both alprazolam and hydroxyzine were rated by the patients as satisfactory premedicants.…”

Characterization of the Binding and Comparison of the Distribution of Benzodiazepine Receptors Labeled with [3H]Diazepam and [3H]Alprazolam

“…There are several other possible explanations for alprazolam's effects that involve pharmacodynamic differences with other benzodiazepine compounds (Fawcett and Kravitz 1982;Sethy and Harris 1982a;St thy 1983). For instance, low doses of alprazolam aPPII ently result in an increase of benzodiazepine receplll numbers, rather than a decrease (Miller et al 1987)1 .…”

ALPRAZOLAM: profilo farmacoeconomico nei disturbi d’ansia e da attacchi di panico

“…(2) Alprazolam è legato per circa l'80% alle proteine plasmatiche e raggiunge lentamente, in 2-3 giorni, l'equilibrio di distribuzione. (2) Il volume di distribuzione è elevato (1,1-1,2 L/kg) e risulta aumentato nei soggetti anziani di sesso maschile e nei soggetti obesi: questo risultato è dovuto all'elevata lipofilia di alprazolam che tende ad accumularsi nel tessuto adiposo, più abbondante nei soggetti obesi e tendenzialmente anche negli anziani. Questo riscontro, tuttavia, non sembra avere conseguenze cliniche e non risulta correlato a differenze di efficacia sedativa.…”

“…Farmaco dotato di potente azione ansiolitica, è tra i più utilizzati in ambito clinico nel trattamento dei disturbi d'ansia, nei disturbi da attacchi di panico e nel disturbo misto d'ansia associata a depressione. (1,2) In questo lavoro presentiamo un profilo farmacologico clinico aggiornato dell'alprazolam come base per alcune considerazioni di tipo farmacoeconomico. …”