Cysteamine, methionine, and penicillamine in the treatment of paracetamol poisoning.

60 patients with paracetamol poisoning have been treated with intravenous cysteamine, L-methionine, or D-penicillamine and the incidence and severity of hepatic necrosis compared with those observed in 70 patients receiving supportive therapy only. Of 31 patients with 4-hour plasma-paracetamol concentrations greater than 250 mug/ml given supportive therapy 22 sustained severe liver damage, 3 died in hepatic failure, and 4 developed acute renal failure. None of 23 similarly poisoned patients given cysteamine within 10 hours of ingestion suffered severe liver damage or renal failure and none died. Cysteamine was partially effective at 10-12 hours, but ineffective 12 hours or more after ingestion. Liver damage was absent or mild in 17 patients given L-methionine within 10-12 hours of ingestion but severe in 3 treated within 10 hours. Of 5 patients treated with D-penicillamine, 1 developed severe liver damage with acute renal failure. It is concluded that cysteamine prevents severe liver damage after paracetamol poisoning if given within 10 hours in adequate dosage.