Influence of KREMEZIN on Serum Concentration in Aspirin Administration.

KREMEZIN® (KR) is an oral adsorbent of spherical carbon, administered to patients with chronic renal failure to prolong the time between hemodialysis through adsorbing uremic toxins in the digestive tract. However, KR has been considered to adsorb not only uremic toxins but also other relative medicines. Therefore, it seems that administration of KR concomitantly with other medicines should be avoided, its influence has not been studied in detail yet. We studied the interaction of KR and aspirin (ASA) as model medicines, in vitro and in five healthy volunteers.In vitro, the interaction of KR and ASA was studied in 1 St and 2 nd JP XIII solution at 37°C, and the concentration of ASA was decreased after 6 hours in the solutions. Healthy volunteers were administered ASA (810 mg) alone or ASA with KR (2 g) at the same time or 1 hour later, and we continuously monitored the serum concentration of salicylates, the metabolites of ASA. The simultaneous administration with KR was found to significantly lower the Cmax and AUC compared with ASA alone or 1 hour later.These findings suggested that KR adsorbs ASA in the digestive tract when administered simultaneously and thus that KR should be administered 1 hour or more after ASA.