Long-term treatment of alcoholic liver disease with propylthiouracil. Part 2: Influence of drop-out rates and of continued alcohol consumption in a clinical trial.

Although propylthiouracil has previously been shown to reduce the risk of mortality in alcoholic liver disease by 60%, generalized use of propylthiouracil for this condition has not occurred. Additional data are therefore presented on four aspects to provide a better assessment of its therapeutic effectiveness. First, the characteristics and the prognosis of dropouts were virtually identical in both the drug and placebo groups. Also the methodology and analysis employed, were designed to control for dropouts, thus providing an accurate interpretation of the outcome. Secondly, since 97% of the patients continued to drink, abstinence was not a precondition for the beneficial effect of propylthiouracil. However, the beneficial effect was observed most clearly in those patients who continued to drink at lower levels, whereas lower level drinking per se did not afford protection in placebo patients. Thirdly, serious side effects or clinical hypothyroidism occurred extremely rarely in these patients, many of whom have now received propylthiouracil for over 4 years. Fourthly, we discuss why the outcome in long-term clinical trials in alcoholic liver disease cannot be compared with effects observed in clinical trials lasting only a few weeks. Journal of Hepatology.