Pharmacokinetics of ethanol in patients with renal failure before and after hemodialysis

We studied the pharmacokinetics of ethanol in seven patients suffering from terminal renal failure before and after they underwent hemodialysis. Ethanol (0.40 g/kg) was administered in the morning after an overnight fast by a constant rate intravenous (IV) infusion over 45 min. After removing a mean fluid volume of 2.46±0.48 liters (±SD), span 1.76–3.43 liters by hemodialysis, the same subjects received a second IV infusion of ethanol after they had eaten lunch. At exactly timed intervals of 0, 45, 90, 105, 120, 135, 150, 165, and 180 min from the start of the infusion, two blood-samples were drawn and the plasma portion of one of them was obtained by centrifugation. The concentration of ethanol in blood and plasma was determined by headspace gas chromatography and the water-content of whole blood was determined from the change in weight after desiccation. Plasma always contained a higher concentration of ethanol than whole blood and the mean plasma/whole blood ratio in patients with renal failure was 1.07:1 (span 1.05–1.10). The rate of ethanol disappearance from blood (β-slope) was faster (0.185±0.013 versus 0.157±0.022 g/l/h), the C₀ value was higher (0.79±0.08 versus 0.73±0.10 g/l) and the apparent volume of distribution (V_d) of ethanol was lower (0.507±0.049 versus 0.558±0.078 l/kg) after hemodialysis. The water content of whole blood was significantly higher (P<0.001) before dialysis (88.6±1.97 g/100 ml) compared with after dialysis (87.4±2.01 g/100 ml). The higher V_d for ethanol and lower C₀ as well as higher blood-water content are to be expected for a over hydrated condition before hemodialysis. The swifter rate of ethanol elimination from blood (β-slope) after hemodialysis should be interpreted with caution because eating a meal before the second infusion of ethanol is a confounding factor. Nevertheless, the rate of elimination of ethanol from blood in patients with renal failure agreed reasonably well with values expected for healthy subjects, namely mean 0.15 g/l/h spanning from 0.10 to 0.20 g/l/h.