Effectiveness and its Prediction of Charcoal Hemoperfusion Treatment in Drug Overdose. A Guideline Based on the Protein Binding Percentage of the Drug.

Abstract

Charcoal hemoperfusion is an effective extracorporeal treatment in cases of drug overdose. It is generally accepted that charcoal hemoperfusion cannot be remove drugs with a relatively large volume of distribution and high protein binding. The volume of distribution of a drug is the most important factor that limits the efficiency of charcoal hemoperfusion. It has be reported that drugs with small volume of distribution (< 50 L) are more efficiently removed by this treatment, based on single compartment kinetics. In contrast, there are no guidelines on the effect of protein binding properties of a drug on its removal by the treatment. So, we attempted to define a guideline based on the protein binding percentage of the drug for use in charcoal hemoperfusion treatment of cases of drug overdose. We measured plasma concentrations of the 20 different (a total of 32) drugs in 12 overdosed patients hemoperfused by an activated charcoal column. The extraction efficiency of a charcoal column, (A-V) /A, immediately after the beginning of hemoperfusion from the concentration in the blood entering (A) and that leaving the column (V), were then determined. From the relationship between extraction efficiency and protein binding percentage of the drugs, we found that drugs with a binding percentage as high as 95% can be removed by charcoal adsorption. Therefore, at binding percentages below 95% the clinical decision of whether to initiate hemoperfusion or not should be made only by consideration of the volume of distribution