Fifteen patients with severe drug intoxication have been treated by a procedure combining hemoperfusion (HP, cellulose-coated activated charcoal, Adsorba C300, Gambro, Sweden) and hemodialysis (HD). The combined HP-HD treatment resulted in a clearance for amobarbital of 121 +/- 10 ml per min (mean +/-SEM), butobarbital 142 +/- 4 ml per min, carbromal 121 +/- 6 ml per min, hexobarbital 181 +/- 13 ml per min, meprobamate 145 +/- 9 ml per min, methaqualone 137 +/- 5 ml per min, phenobarbital 138 +/- 4 ml per min, and secobarbital 125 +/- 4 ml per min. There was no decrease in drug extraction even after 30 hours of treatment. Duration of treatment (6 to 33 hours) was determined by the clinical state of the patient. Prolonged HP-HD seemed to ben an efficient and sage procedure. Of 15 patients treated, 14 regained consciousness and 12 survived. The platelet count decreased, necessitating cessation of treatment in two cases. There was extraction of oxygen by the charcoal column, without influence on patient Po2. Glucose, urea, creatinine, uric acid, phosphate, and triglycerides were removed by adsorption on charcoal and/or dialysis.