MERCK: PROSCAR DOES WHAT IT'S DESIGNED TO DO
Your article about Proscar, Merck's new drug for symptomatic benign prostate enlargement ("Critics are ganging up on Merck's new wonder drug," Top of the News, July 20), does not fully reflect Merck's knowledge about the drug's efficiency and safety. In fact, several questions raised by the article are answered in the prescribing information for doctors, which was not widely available at the time of publication.
The comments about effectiveness lose sight of what Proscar is designed to do: lower the levels of the key hormone that contributes to prostate enlargement in aging men. Treatment leads to rapid shrinkage of the enlarged gland in most patients. Some patients additionally experience increases in urine flow and symptom relief. Shrinkage of the gland and symptom and urine flow improvements appear to be sustained for as long as two years in patients who have chosen to continue taking Proscar.
Another topic is the effect of Proscar on PSA (prostate-specific antigen). This protein, which is released into the blood by the prostate, is a marker of prostate size or activity. Elevations in PSA may be linked to prostate cancer, and PSA testing is increasingly being used as one of several tools for the diagnosis of prostate cancer.
Since Proscar lowers blood levels of PSA, the prescribing information for doctors points out that rectal exams and other tests for prostate cancer should be carried out before any man begins treatment with Proscar and periodically after that. Doctors are also cautioned to check into any sustained increases in PSA levels in patients taking Proscar.
From the clinical trials in over 1,600 patients, it does not appear that Proscar altered the rate of prostate cancer detection. Our hope is that the continued monitoring of patients taking Proscar will improve their rate of early cancer detection. On the other hand, it should be understood that Proscar is not indicated to treat prostate cancer.
Our data on the effects of Proscar on PSA and prostate cancer were reviewed in detail to the satisfaction of the Food & Drug Administration and international regulatory authorities, including those in Britain, France, and Italy, where Proscar is approved.
Dr. Louis M. Sherwood
Medical & Scientific Affairs
U.S. Human Health Div.
Merck & Co.
West Point, Pa.