POST-TREATMENT DETECTION OF AZITHROMYCIN IN HIGH-VAGINAL SWABS USING LIQUID CHROMATOGRAPHY AND TANDEM MASS SPECTROMETRY (LC-MS/MS)

Abstract

Recent data have raised questions over the efficacy of azithromycin 1g for the treatment of chlamydia infection. In order to measure effective absorption, we developed a protocol to quantify the concentration of azithromycin using liquid chromatography and tandem mass spectrometry (LC-MS/MS) in self-collected high-vaginal swabs. Ten healthy women were asked to self-collect a high-vaginal swab (baseline) prior to taking a 1g dose of azithromycin. A blood sample was collected four hours later to determine plasma concentrations of azithromycin. Participants then self-collected a high vaginal swab each day for a further 9 days. All swabs were preserved in 1ml of 100% Methanol and stored at –80°C..