Alprazolam: chemistry

Alprazolam belongs to the benzodiazepine class [1], and more specifically to a subgroup called triazolobenzodiazepines — it was the first of these marketed in the United States and Canada [2].

Alprazolam is a GABA agonist [3]. It works by decreasing abnormal excitement in the brain [1], and it is used as an anxiolytic, anticonvulsant, sedative, and muscle relaxant [3].

Peak serum levels are reached in 0.7 to 2.1 hours [2], and after a single 1 mg dose, peak plasma concentration lands at 12 to 22 micrograms per liter within a similar 0.7 to 1.8 hour window [4]. Its elimination half-life runs 9 to 16 hours [4], with a serum half-life cited as 12 to 15 hours [2].

Alprazolam is broken down by hepatic microsomal oxidation [4]. Two of its metabolites, alpha-hydroxy- and 4-hydroxy-alprazolam, bind the same receptor less strongly than the parent drug [4]. Side effects associated with alprazolam increase in frequency with higher steady-state plasma concentrations [4].

References

1. Alprazolam: MedlinePlus Drug Information — MedlinePlus, National Library of Medicine
2. Alprazolam: pharmacokinetics, clinical efficacy, and mechanism of action — PubMed (Journal article)
3. Alprazolam | C17H13ClN4 | CID 2118 — PubChem, National Institutes of Health
4. Clinical pharmacokinetics of alprazolam. Therapeutic implications — Clinical Pharmacokinetics (Springer)