How certain drugs interfere negatively with the Jaffé reaction for creatinine

Area of Science:

• Clinical chemistry
• Analytical toxicology

Background:

• The Jaffé reaction is a common method for determining creatinine levels.
• Accurate creatinine measurement is crucial for assessing kidney function.
• Potential interference from medications can affect diagnostic test results.

Purpose of the Study:

• To investigate the interference of phenacemide and cephalothin in creatinine determination using the Jaffé reaction.
• To characterize the nature and timing of interference caused by these drugs.

Main Methods:

• Assessing the impact of phenacemide and cephalothin on creatinine measurements via the Jaffé reaction.
• Analyzing the absorbance changes of drug-picrate chromophores over time.
• Evaluating interference in analytical systems employing kinetic measurements.

Main Results:

• Phenacemide and cephalothin interfere with the Jaffé reaction for creatinine determination.
• Drug-picrate chromophores exhibit maximum absorbance within the first minute, followed by a decrease.
• Negative interference occurs in kinetic assays when measurement intervals include decreasing absorbance phases.

Conclusions:

• Phenacemide and cephalothin can lead to inaccurate creatinine measurements.
• The timing of absorbance changes is critical for understanding interference in kinetic assays.
• Awareness of this interference is essential for reliable clinical chemistry diagnostics.