Updated labeling for troglitazone (Rezulin, Parke-Davis, Morris Plains, NJ) includes a new recommendation that liver enzyme levels should be measured in patients initially, then monthly for the first 6 months of treatment, every other month for the next 6 months, and periodically thereafter. The new labeling also makes the warning regarding potential liver toxicity more prominent and updates the effectiveness information to state that monotherapy should be discontinued if effective results are not achieved after a 6- to 8-week trial.
Nightingale SL. Rezulin Labeling Updated to Recommend More Frequent Patient Monitoring. JAMA. 1998;279(1):9. doi:10.1001/jama.279.1.9