Drug-lab interactions: implications for nutrition support. Acetylcysteine interference with urine ketone test

Area of Science:

• Clinical Chemistry
• Pharmacology
• Laboratory Medicine

Background:

• Medications can impact clinical laboratory test results through in vivo or in vitro mechanisms.
• Understanding these interactions is crucial for accurate patient diagnosis and management.
• In vitro interference leads to erroneous assay results that are clinically misleading.

Observation:

• A specific case of acetylcysteine interference with urine ketone testing was identified.
• This interference affected the accuracy of the ketone assay.
• The erroneous result could lead to misinterpretation if not recognized.

Findings:

• Acetylcysteine can directly interfere with the chemical reaction of urine ketone tests.
• This interference presents as a false positive or false negative result, depending on the assay.
• Accurate interpretation requires awareness of potential drug interferences.

Implications:

• Healthcare professionals must consider medication history when evaluating abnormal laboratory findings.
• Thorough medication reviews are essential to differentiate true analyte changes from assay interference.
• This case underscores the importance of continuous education on drug-interfering effects in laboratory diagnostics.