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Alprazolam or , available as the trade name Xanax among others, is a short-acting anxiolytic of the benzodiazepine class. It is commonly used for the treatment of panic disorder, and anxiety disorders, such as generalized anxiety disorder (GAD) or social anxiety disorder (SAD).〔 It was the 12th most prescribed medicine in 2010. Alprazolam, like other benzodiazepines, binds to specific sites on the GABAA receptor. It possesses anxiolytic, sedative, hypnotic, skeletal muscle relaxant, anticonvulsant, and amnestic properties. Alprazolam is available for oral administration in compressed tablet (CT) and extended-release capsule (XR) formulations. Alprazolam has a fast onset of action and symptomatic relief. Ninety percent of peak effects are achieved within the first hour of using either the CT formulation or the XR formulation in preparation for panic disorder, and full peak effects are achieved in 1.5 and 1.6 hours respectively. Peak benefits achieved for generalized anxiety disorder (GAD) may take up to a week. Tolerance to the anxiolytic/antipanic effects is controversial with some authoritative sources reporting the development of tolerance,〔 and others reporting no development of tolerance;〔 tolerance will, however, develop to the sedative-hypnotic effects within a couple of days.〔 Withdrawal symptoms or rebound symptoms may occur after ceasing treatment abruptly following a few weeks or longer of steady dosing, and may necessitate a gradual dose reduction.〔〔 Alprazolam was first released by Upjohn (now a part of Pfizer). It is covered under , which was filed on 29 October 1969, granted on 19 October 1976, and expired in September 1993. Alprazolam was released in 1981. The first approved indication was panic disorder and within two years of its original marketing Upjohn's Xanax became a blockbuster drug in the US. Presently, alprazolam is the most prescribed and the most misused benzodiazepine on the U.S. retail market. The potential for misuse among those taking it for medical reasons is controversial with some expert reviews stating that the risk is low and similar to that of other benzodiazepine drugs〔 and others stating that there is a substantial risk of misuse and dependence in both patients and non-medical users of alprazolam and that the pharmacological properties of alprazolam, high affinity binding, high potency, having a short elimination half-life as well as a rapid onset of action may increase the misuse potential of alprazolam.〔 Compared to the large number of prescriptions, relatively few individuals increase their dose on their own initiative or engage in drug-seeking behavior. Alprazolam is classified as a schedule IV controlled substance by the U.S. Drug Enforcement Administration (DEA). ==Medical uses== Alprazolam is mostly used to treat anxiety disorders, panic disorders, and nausea due to chemotherapy.〔 The FDA label advises that the physician should periodically reassess the usefulness of the drug.〔 Alprazolam may also be indicated for the treatment of generalized anxiety disorder, as well as for the treatment of anxiety conditions with co-morbid depression. Alprazolam is also often prescribed with instances of hypersomnia and co-morbid sleep deficits. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Alprazolam」の詳細全文を読む スポンサード リンク
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