Alprazolam, most often referred to by it's trade name Xanax, is a benzodiazepine sedative commonly used in the treatment of anxiety disorders. it is available in both a quick release form and a slow release form, but in both cases it acts much faster than similar drugs providing relief of symptoms in under fifteen minutes in most cases. It is both the most commonly prescribed and abused benzodiazepine.
However, sudden withdrawal of the drug can cause rebound symptoms. As such, users often have to be weaned off the drug if they become tolerant to it.