Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS)

Lenka A. Vodstrcil, Thusitha W T Rupasinghe, Fabian Yuh Shiong Kong, Dedreia Tull, Karen Worthington, Marcus Y. Chen, Wilhelmina M Huston, Peter Timms, Malcolm J McConville, Christopher K. Fairley, Catriona S. Bradshaw, Sepehr N Tabrizi, Jane Simone Hocking

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Background Azithromycin is recommended for the treatment of uncomplicated urogenital chlamydia infection although the standard 1gram dose sometimes fails to eradicate the infection (treatment failure). One hypothesis proposed for treatment failure has been insufficient levels of the antibiotic at the site of infection. We developed an assay using liquid chromatography and tandem mass spectrometry (LC-MS/MS) to measure azithromycin concentration in high-vaginal swabs and monitor how concentration changes over time following routine azithromycin treatment. Methods Azithromycin concentrations were measured in two groups of women either within the first 24h of taking a 1g dose (N = 11) or over 9 days (N = 10). Azithromycin concentrations were normalised to an internal standard (leucine enkephalin), and the bulk lipid species phosphatidylcholine [PC(34:1)], using an Agilent 6490 triple quadrupole instrument in positive ionisation mode. The abundances of azithromycin, PC(34:1), and leu-enkephalin were determined by multiple reaction monitoring and absolute levels of azithromycin estimated using standard curves prepared on vaginal specimens. Results Vaginal azithromycin concentrations of women were rapidly obtained after 5h post-treatment (mean concentration = 1031mcg/mg of lipid, range = 173-2693mcg/mg). In women followed for 9 days, peak concentrations were highest after day 2 (mean concentration = 2206mcg/mg, range = 721-5791mcg/mg), and remained high for at least 9 days with a mean concentration of 384mcg/mg (range = 139-1024mcg/mg) on day 9. Conclusion Our study confirmed that a single 1g dose of azithromycin is rapidly absorbed and remains in the vagina at relatively high levels for at least a week, suggesting that poor antibiotic absorption is unlikely to be an explanation for treatment failure.

Original languageEnglish
Article numbere0177615
Number of pages13
JournalPLoS ONE
Volume12
Issue number5
DOIs
Publication statusPublished - 1 May 2017

Cite this

Vodstrcil, Lenka A. ; Rupasinghe, Thusitha W T ; Kong, Fabian Yuh Shiong ; Tull, Dedreia ; Worthington, Karen ; Chen, Marcus Y. ; Huston, Wilhelmina M ; Timms, Peter ; McConville, Malcolm J ; Fairley, Christopher K. ; Bradshaw, Catriona S. ; Tabrizi, Sepehr N ; Hocking, Jane Simone. / Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS). In: PLoS ONE. 2017 ; Vol. 12, No. 5.
@article{f4ae49605d5342e6af52fb7379780eb5,
title = "Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS)",
abstract = "Background Azithromycin is recommended for the treatment of uncomplicated urogenital chlamydia infection although the standard 1gram dose sometimes fails to eradicate the infection (treatment failure). One hypothesis proposed for treatment failure has been insufficient levels of the antibiotic at the site of infection. We developed an assay using liquid chromatography and tandem mass spectrometry (LC-MS/MS) to measure azithromycin concentration in high-vaginal swabs and monitor how concentration changes over time following routine azithromycin treatment. Methods Azithromycin concentrations were measured in two groups of women either within the first 24h of taking a 1g dose (N = 11) or over 9 days (N = 10). Azithromycin concentrations were normalised to an internal standard (leucine enkephalin), and the bulk lipid species phosphatidylcholine [PC(34:1)], using an Agilent 6490 triple quadrupole instrument in positive ionisation mode. The abundances of azithromycin, PC(34:1), and leu-enkephalin were determined by multiple reaction monitoring and absolute levels of azithromycin estimated using standard curves prepared on vaginal specimens. Results Vaginal azithromycin concentrations of women were rapidly obtained after 5h post-treatment (mean concentration = 1031mcg/mg of lipid, range = 173-2693mcg/mg). In women followed for 9 days, peak concentrations were highest after day 2 (mean concentration = 2206mcg/mg, range = 721-5791mcg/mg), and remained high for at least 9 days with a mean concentration of 384mcg/mg (range = 139-1024mcg/mg) on day 9. Conclusion Our study confirmed that a single 1g dose of azithromycin is rapidly absorbed and remains in the vagina at relatively high levels for at least a week, suggesting that poor antibiotic absorption is unlikely to be an explanation for treatment failure.",
author = "Vodstrcil, {Lenka A.} and Rupasinghe, {Thusitha W T} and Kong, {Fabian Yuh Shiong} and Dedreia Tull and Karen Worthington and Chen, {Marcus Y.} and Huston, {Wilhelmina M} and Peter Timms and McConville, {Malcolm J} and Fairley, {Christopher K.} and Bradshaw, {Catriona S.} and Tabrizi, {Sepehr N} and Hocking, {Jane Simone}",
year = "2017",
month = "5",
day = "1",
doi = "10.1371/journal.pone.0177615",
language = "English",
volume = "12",
journal = "PLoS ONE",
issn = "1932-6203",
publisher = "Public Library of Science",
number = "5",

}

Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS). / Vodstrcil, Lenka A.; Rupasinghe, Thusitha W T; Kong, Fabian Yuh Shiong; Tull, Dedreia; Worthington, Karen; Chen, Marcus Y.; Huston, Wilhelmina M; Timms, Peter; McConville, Malcolm J; Fairley, Christopher K.; Bradshaw, Catriona S.; Tabrizi, Sepehr N; Hocking, Jane Simone.

In: PLoS ONE, Vol. 12, No. 5, e0177615, 01.05.2017.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Measurement of tissue azithromycin levels in self-collected vaginal swabs post treatment using liquid chromatography and tandem mass spectrometry (LC-MS/MS)

AU - Vodstrcil, Lenka A.

AU - Rupasinghe, Thusitha W T

AU - Kong, Fabian Yuh Shiong

AU - Tull, Dedreia

AU - Worthington, Karen

AU - Chen, Marcus Y.

AU - Huston, Wilhelmina M

AU - Timms, Peter

AU - McConville, Malcolm J

AU - Fairley, Christopher K.

AU - Bradshaw, Catriona S.

AU - Tabrizi, Sepehr N

AU - Hocking, Jane Simone

PY - 2017/5/1

Y1 - 2017/5/1

N2 - Background Azithromycin is recommended for the treatment of uncomplicated urogenital chlamydia infection although the standard 1gram dose sometimes fails to eradicate the infection (treatment failure). One hypothesis proposed for treatment failure has been insufficient levels of the antibiotic at the site of infection. We developed an assay using liquid chromatography and tandem mass spectrometry (LC-MS/MS) to measure azithromycin concentration in high-vaginal swabs and monitor how concentration changes over time following routine azithromycin treatment. Methods Azithromycin concentrations were measured in two groups of women either within the first 24h of taking a 1g dose (N = 11) or over 9 days (N = 10). Azithromycin concentrations were normalised to an internal standard (leucine enkephalin), and the bulk lipid species phosphatidylcholine [PC(34:1)], using an Agilent 6490 triple quadrupole instrument in positive ionisation mode. The abundances of azithromycin, PC(34:1), and leu-enkephalin were determined by multiple reaction monitoring and absolute levels of azithromycin estimated using standard curves prepared on vaginal specimens. Results Vaginal azithromycin concentrations of women were rapidly obtained after 5h post-treatment (mean concentration = 1031mcg/mg of lipid, range = 173-2693mcg/mg). In women followed for 9 days, peak concentrations were highest after day 2 (mean concentration = 2206mcg/mg, range = 721-5791mcg/mg), and remained high for at least 9 days with a mean concentration of 384mcg/mg (range = 139-1024mcg/mg) on day 9. Conclusion Our study confirmed that a single 1g dose of azithromycin is rapidly absorbed and remains in the vagina at relatively high levels for at least a week, suggesting that poor antibiotic absorption is unlikely to be an explanation for treatment failure.

AB - Background Azithromycin is recommended for the treatment of uncomplicated urogenital chlamydia infection although the standard 1gram dose sometimes fails to eradicate the infection (treatment failure). One hypothesis proposed for treatment failure has been insufficient levels of the antibiotic at the site of infection. We developed an assay using liquid chromatography and tandem mass spectrometry (LC-MS/MS) to measure azithromycin concentration in high-vaginal swabs and monitor how concentration changes over time following routine azithromycin treatment. Methods Azithromycin concentrations were measured in two groups of women either within the first 24h of taking a 1g dose (N = 11) or over 9 days (N = 10). Azithromycin concentrations were normalised to an internal standard (leucine enkephalin), and the bulk lipid species phosphatidylcholine [PC(34:1)], using an Agilent 6490 triple quadrupole instrument in positive ionisation mode. The abundances of azithromycin, PC(34:1), and leu-enkephalin were determined by multiple reaction monitoring and absolute levels of azithromycin estimated using standard curves prepared on vaginal specimens. Results Vaginal azithromycin concentrations of women were rapidly obtained after 5h post-treatment (mean concentration = 1031mcg/mg of lipid, range = 173-2693mcg/mg). In women followed for 9 days, peak concentrations were highest after day 2 (mean concentration = 2206mcg/mg, range = 721-5791mcg/mg), and remained high for at least 9 days with a mean concentration of 384mcg/mg (range = 139-1024mcg/mg) on day 9. Conclusion Our study confirmed that a single 1g dose of azithromycin is rapidly absorbed and remains in the vagina at relatively high levels for at least a week, suggesting that poor antibiotic absorption is unlikely to be an explanation for treatment failure.

UR - http://www.scopus.com/inward/record.url?scp=85019461740&partnerID=8YFLogxK

U2 - 10.1371/journal.pone.0177615

DO - 10.1371/journal.pone.0177615

M3 - Article

VL - 12

JO - PLoS ONE

JF - PLoS ONE

SN - 1932-6203

IS - 5

M1 - e0177615

ER -