Simultaneous determination of trimethoprim and sulfamethoxazole in dried plasma and urine spots

Bioanalysis. 2015;7(9):1137-49. doi: 10.4155/bio.15.38.


Background: Trimethoprim-sulfamethoxazole (TMP-SMX) is an antimicrobial drug combination commonly prescribed in children and adults. The study objectives were to validate and apply an HPLC-MS/MS method to quantify TMP-SMX in dried plasma spots (DPS) and dried urine spots (DUS), and perform a comparability analysis with liquid matrices.

Results: For TMP the validated range was 100-50,000 ng/ml for DPS and 500-250,000 ng/ml for DUS; for SMX, the validated range was 1000-500,000 ng/ml for both DPS and DUS. Good agreement was noted between DPS/DUS and liquid plasma and urine samples for TMP, while only modest agreement was observed for SMX in both matrices.

Conclusion: A precise, accurate and reproducible method was developed to quantify TMP-SMX in DPS and DUS samples.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Calibration
  • Child
  • Chromatography, High Pressure Liquid
  • Dried Blood Spot Testing / methods*
  • Humans
  • Tandem Mass Spectrometry
  • Time Factors
  • Trimethoprim, Sulfamethoxazole Drug Combination / blood*
  • Trimethoprim, Sulfamethoxazole Drug Combination / urine*
  • Urinalysis / methods*


  • Trimethoprim, Sulfamethoxazole Drug Combination