Alprazolam is readily absorbed from the gastrointestinal tract with a bioavailability of 80–100%. The peak plasma concentration is achieved in 1–2 hours. Most of the drug is bound to plasma protein, mainly serum albumin. Alprazolam is hydroxylated in the liver to α-hydroxyalprazolam, which is also pharmacologically active but much less so than the parent compound. This and other metabolites are later excreted in urine as glucuronides. Some of the drug is also excreted in unchanged form. The elderly clear alprazolam more slowly than younger adults.