Prediction of iopromide reduction rates during haemodialysis using an in vitro dialysis system.
BACKGROUND
In clinical studies, it has been difficult to evaluate the influence of haemodialysis (HD) parameters on HD clearance (CL(HD)) and reduction rate (RR) of non-ionic contrast medium during HD sessions. We therefore predicted clinical values of CL(HD) and RR of iopromide, a non-ionic contrast medium, from findings obtained from in vitro experiments, and confirmed that these predictive values were comparable with the actual values in clinical cases.


METHODS
We developed a correlation equation for predicting CL(HD) on the basis of in vitro HD experiments by varying blood flow rates between 100 and 200 ml/min with a cuprammonium rayon dialyser (AM-SD-10H). Total body clearance of iopromide (CL(PT)) was estimated by the Cockroft-Gault equation. The volume of distribution (V(d)) was obtained from the reported value. By using the HD and three pharmacokinetic parameters (CL(HD), CL(PT) and V(d)), we predicted CL(HD) and RR for seven patients undergoing HD after the administration of iopromide.


RESULTS
In the in vitro study, the mean values (+/-SD) of iopromide clearance at blood flow rates of 100, 150 and 200 ml/min were 45.35 (2.54), 53.88 (6.46) and 57.61 (4.72) ml/min, respectively. There were highly significant correlations between clearance and blood flow rate (r = 0.975). Although the predicted CL(HD) showed a tendency towards underestimation, a good correlation was found. Predicted RR values were similar to observed values except for one case.


CONCLUSIONS
The in vitro model used in the present study provides pertinent information about CL(HD) and is helpful for predicting RR during HD in individual patients undergoing HD.
Teraoka
Tomohisa
T
Department of Drug Information and Communication, Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba-shi, Chiba 260-8675, Japan. tera@p.chiba-u.ac.jp
Sugai
Takao
T
Nakamura
Sunao
S
Hirasawa
Hiroyuki
H
Oda
Shigeto
S
Shiga
Hidetoshi
H
Suga
Mio
M
Yamane
Shinji
S
Ishii
Hiroyuki
H
Yamagata
Shin-ichi
S
Satoh
Nobunori
N
Ueda
Shiro
S
D003287:Contrast Media / Q000493:pharmacokinetics*; D005544:Forecasting; D007472:Iohexol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008657:Metabolic Clearance Rate; D008961:Models, Structural; D006435:Renal Dialysis
D003287:Contrast Media; D007472:Iohexol; C038192:iopromide