Unreliable drug histories, analgesics, and changes in renal function

Area of Science:

• Pharmacology
• Nephrology
• Clinical Chemistry

Background:

• Analgesic overuse is a common concern.
• Accurate assessment of patient medication history is crucial for clinical management.
• Previous studies have raised concerns about the renal effects of analgesics.

Purpose of the Study:

• To evaluate the accuracy of patient self-reported analgesic use.
• To investigate the relationship between analgesic intake and renal function markers.
• To assess the impact of specific analgesics (aspirin, paracetamol) on serum urea levels.

Main Methods:

• 109 outpatients provided urine and blood samples.
• Questionnaires assessed self-reported daily and recent (3-day) analgesic use.
• Urine and serum samples were analyzed for paracetamol and aspirin metabolites.
• Serum urea levels were correlated with reported analgesic consumption.

Main Results:

• 41% reported daily analgesic use; 54% reported use in the prior 3 days.
• 5 (42%) patients denying use had detectable paracetamol/aspirin in urine.
• 10 (29%) patients denying recent use also had detectable levels.
• Mean serum urea increased with analgesic use, significantly higher in combination users (aspirin + paracetamol).

Conclusions:

• Patient self-reported analgesic history is often inaccurate.
• Paracetamol, like phenacetin, may pose risks to renal function, particularly with combined use.
• Monitoring renal function in regular analgesic users is recommended.