[Triamterene and renal calculi]

Area of Science:

• Nephrology
• Pharmacology
• Analytical Chemistry

Background:

• Triamterene is a diuretic medication.
• Kidney stones (calculi) can form due to various factors, including medication use.
• Understanding the composition of drug-induced calculi is crucial for patient management.

Observation:

• Analysis of four triamterene-containing calculi from 1979-1981.
• Calculi composition showed triamterene (35%) and seven metabolites.
• Key metabolites identified include p-hydroxy-triamterene (5-10%) and p-hydroxytriamterene estersulfate (40-55%).

Findings:

• The drug layers in the analyzed calculi exhibited consistent composition.
• A potential metabolic or physicochemical link between triamterene and uric acid was hypothesized.
• Triamterene calculi represent 0.4% of all observed lithiasis.

Implications:

• Suggests an estimated 150-200 undetected triamterene calculi are eliminated annually in France.
• Emphasizes the value of detailed calculus analysis using physical methods like infrared spectrometry.
• Informs clinical practice regarding potential calculus formation in patients using triamterene.