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Test ID TMP Trimethoprim, Serum

Useful For

Monitoring trimethoprim therapy to ensure drug absorption, clearance, or compliance

Method Name

Liquid-Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Trimethoprim, S

Specimen Type

Serum Red

Specimen Required

Collection Container/Tube: Red top (gel tubes/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Serum for a peak level should be drawn at least 60 minutes after a dose.

2. Centrifuge within 2 hours of collection.

Specimen Minimum Volume

0.2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 28 days
  Ambient  28 days
  Frozen  28 days

Reference Values

>2.0 mcg/mL

Day(s) Performed

Monday, Thursday

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
TMP Trimethoprim, S 11005-6


Result ID Test Result Name Result LOINC Value
80146 Trimethoprim, S 11005-6

Test Classification

This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

Report Available

2 to 5 days

NY State Approved



If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.