Accelerator mass spectrometry (AMS) is an ultrasensitive technique to detect radiolabeled compounds. We administered a microdose (100 νg) of 14 C-labeled zidovudine (ZDV) with or without a standard unlabeled dose (300mg) to healthy volunteers. Intracellular ZDV-triphosphate (ZDV-TP) concentration was measured using AMS and liquid chromatography-tandem mass spectrometry (LC/MS/MS). AMS analysis yielded excellent concordance with LC/MS/MS and was 30,000-fold more sensitive. The kinetics of intracellular ZDV-TP formation changed several-fold over the dose range studied (100νg-300mg). AMS holds promise as a tool for quantifying intracellular drug metabolites and other biomediators in vivo.
ASJC Scopus subject areas
- Pharmacology (medical)