Liver Warning On Rezulin Label Sparks Share Fall

Warner-Lambert's Parke-Davis division has sent out "Dear Doctor" lettersadvising physicians that it has revised the labeling for its new insulin sensititizer for diabetes, Rezulin (troglitazone) to include a warning that patients on the drug should receive periodic monitoring of liver enzyme (serum transaminase) levels. The move comes in response to reports of liver injury associated with the drug.

Shares in W-L fell $4.75 on the day of the announcement (November 3) to close at $138.63, down 3.3%, but the fall was temporary, with the stock regaining over half its decline the following day (as the Marketletter went to press).

Glaxo Wellcome and Sankyo, which comarket the drug as Romozin in the UK, have also sent out letters to physicians. The drug was originally discovered by Sankyo, which markets it in Japan as Noscal. GW has rights to sell it in certain European countries, South Africa and Israel.