STUDIES ON PARACETAMOL BINDING TO SERUM-PROTEINS

There is a limited amount of data on the binding of paracetamol to pla sma proteins. It has been suggested that binding might influence the a bility of some analytical methods to quantify the total amount of drug present in the plasma fraction-the basis of clinical experience in ri sk assessment and antidote usage. We have investigated the binding of paracetamol to plasma proteins using an ultrafiltration technique. In overdose and spiked uraemic plasma samples the mean percentage of para cetamol bound was 24.1 (1SD = 7.0) with no significant correlation wit h drug levels or degree of uraemia. There is a small but significant i ncrease in binding with increasing serum albumin concentration both in plasma (r(s) = 0.549, P = 0.014) and in pure serum albumin solutions (r(s) = 0.848, P < 0.001).