These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Alprazolam as a probe for CYP3A using a single blood sample: pharmacokinetics of parent drug, and of alpha- and 4-hydroxy metabolites in healthy subjects.
    Author: Wennerholm A, Allqvist A, Svensson JO, Gustafsson LL, Mirghani RA, Bertilsson L.
    Journal: Eur J Clin Pharmacol; 2005 Apr; 61(2):113-8. PubMed ID: 15806426.
    Abstract:
    OBJECTIVES: (1) To determine the pharmacokinetic parameters of alprazolam and its two metabolites in plasma from healthy volunteers; (2) to identify a suitable single time point to take a plasma sample for CYP3A phenotyping. METHODS: Twelve healthy Swedish volunteers received a single oral dose of 1 mg alprazolam. Blood samples were collected before drug intake and frequently up to 72 h thereafter. A liquid-chromatography/mass-spectrometry (LC/MS) method was used for the quantification of alprazolam, and 4- and alpha-hydroxyalprazolam. RESULTS: The interindividual variation in the area under the concentration-time curve (AUC) was two, three and fourfold for alprazolam, 4-hydroxyalprazolam and alpha-hydroxyalprazolam, respectively. Plasma concentration ratios collected between 1 h and 48 h for both alprazolam/4-hydroxyalprazolam and alprazolam/alpha-hydroxyalprazolam correlated significantly to the corresponding AUC0-infinity ratios. CONCLUSIONS: The metabolic ratios of alprazolam to respective metabolite in a single plasma sample at 3-24 h are suggested to reflect the alprazolam 4- and alpha-hydroxylation activities. In future, it will be important to study these activities in populations where CYP3A5, in addition to CYP3A4, is expressed at a high frequency and to clarify the relative importance of the two enzymatic pathways for in vivo clearance of alprazolam.
    [Abstract] [Full Text] [Related] [New Search]