Abstract The response to treatment in sixty-five episodes of hepatic coma was studied in sixty-three patients. Thirty-four patients were treated with a regimen of protein withdrawal, oral broad-spectrum antibiotics and enemas, which had the object of reducing the formation and absorption of toxic nitrogenous substances of intestinal origin. Twenty-one patients improved during treatment and thirteen recovered. Of thirty patients who received varying amounts of protein during hepatic coma, five showed improvement and two survived, but the two groups were not entirely comparable. Additional therapy with glutamic acid, aspartic acid, cortisone, hydrocortisone or lipoic acid was given on forty-seven occasions. No additional benefit could be attributed to the exhibition of these specific agents, and it was concluded that the therapy of choice was protein withdrawal and oral administration of broad-spectrum antibiotics. The majority of those treated were alcoholic patients with severe liver disease, and hepatic function was the most important factor in prognosis. Protein withdrawal and antibiotics reduced arterial blood ammonia concentrations. Like glutamic acid, aspartic acid had a transient effect on blood ammonia values in two patients. Lipoic acid had no constant effect on arterial blood ammonia, pyruvate or α-ketoglutarate concentrations.