Semiautomated assay for indapamide in biological fluids.

A sensitive fluorescence procedure for the determination of indapamide in plasma and whole blood was developed. The procedure requires preextraction of the biological sample followed by continuous-flow analysis. The assay is sensitive to indapamide levels of 25 ng/ml in plasma and blood. A linear response from 25 to 200 ng/ml is observed. The procedure also can be used to measure urinary levels of indapamide. The assay has been used to obtain whole blood and plasma level curves from subjects receiving 2.5 mg of indapamide.