Pos-648 medicines intake influences accuracy of the uremic retention molecules’ optical monitoring in spent dialysate: the case of uremic toxin uric acid and paracetamol

Uric acid (UA) is a representative of the small water-soluble uremic retention solutes [1] and the main UV-absorbing solute (chromophore) in spent dialysate at 280 nm [2]. Optical monitoring of the uremic marker molecules in spent dialysate has been proposed [3] to estimate on-line concentration and removal of uremic toxins, whereas Kt/V determination by UV-absorbance of spent dialysate has been clinically validated and is used in clinical practice [4]. Although it has been shown that paracetamol (PAR) and its metabolites have a considerable role in the UV-absorbance signal of spent dialysate [2, 5], there is insufficient knowledge about the effect of drug administration on the accuracy of the optical method.