Hemoperfusion is more effective than hemodialysis in clearing drugs from the blood of patients with acute overdose. In addition, the clinical improvement in the depth of coma is dramatic during hemoperfusion. There is normalization of the respiratory and circulatory systems usually within one hour, and response to verbal command within a few hours of initiating treatment. Amberlite XAD-4 is an unchanged polystyrene resin with a particular adsorptive attraction for lipid-soluble drugs. It is a more effective adsorbent than some of the coated or uncoated carbons in clearing blood of most of the drugs commonly involved in life-threatening acute overdose.