Alprazolam, also known under the trade names]] Xanax, Xanor and Niravam, is a short-acting drug of the benzodiazepine class used to treat moderate to severe anxiety disorders, panic attacks, and is used as an adjunctive treatment for [[anxiety associated with moderate depression. It is also available in an extended-release form, Xanax XR, both of which now available in generic form. Alprazolam possesses anxiolytic, sedative, hypnotic, anticonvulsant, and muscle relaxant properties.

Alprazolam may be habit-forming, and long-term use and/or abuse may cause a physical dependence to develop along with withdrawal reactions during abrupt or rapid discontinuation. In the USA, alprazolam is a schedule IV controlled substance under the Controlled Substances Act.

History

Alprazolam was first synthesized by Upjohn (now a part of Pfizer). It is covered under , which was filed on October 29, 1969, granted on October 19, 1976 and expired in September 1993. Alprazolam was released in 1981. The first approved indication was panic disorder. Upjohn took this direction at the behest of a young psychiatrist David Sheehan. Sheehan's suggestion was to use the new distinction the DSM-III created in the classification of anxiety disorders between generalized anxiety disorder (GAD) and panic disorder in order to market alprazolam specifically for the latter. Panic disorder was, at that point, perceived to be rare and treatable only with tricyclic antidepressants; benzodiazepines were thought to be ineffective. However, from his clinical experience, Sheehan knew panic disorder to be both widespread among the populace and responsive to benzodiazepines. He suggested to Upjohn that marketing alprazolam for panic disorder would both cover new diagnostic territory and emphasize the unique potency of this drug. Sheehan describes that the first group of patients treated by alprazolam was so impressed by its action that they knew outright — this drug was going to be a hit. A few of those patients actually pooled their money and purchased stock in Upjohn. Several months later, when alprazolam was approved by the United States Food and Drug Administration, they sold out and made a profit.

Alprazolam has an exceptional history insofar as soon after its introduction a large number of case reports were published in the medical literature of severe withdrawal symptom-related case reports of psychoses, seizures, and intense rebound anxiety upon discontinuation of alprazolam.

Pharmacology

Alprazolam is classed as a high-potency benzodiazepine and is a triazolobenzodiazepine, that is, a benzodiazepine with a triazole ring attached to its structure. Benzodiazepines produce a variety of therapeutic and adverse effects by binding to the benzodiazepine site on the GABA_A receptor and modulating the function of the GABA receptor, the most prolific inhibitory receptor within the brain. The GABA chemical and receptor system produces inhibitory or calming effects of alprazolam on the nervous system. The GABA_A receptor is made up from 5 subunits out of a possible 19, and GABA_A receptors made up of different combinations of subunits have different properties, different locations within the brain, and, what is significant, different activities with regard to benzodiazepines.