There have been a number of studies that have suggested that some common medications will alter prostate-specific antigen (PSA) levels.

Researchers from Stanford University School of Medicine, Stanford, CA., investigated the impact of individual and combinations of common medications thought to impact PSA in a large cross-sectional study of the United States population.

The study included men > /= 40 years old without prostate cancer from the 2003 to 2004 and 2005 to 2006 cycles of the National Health and Nutrition Examination Survey (NHANES). Men with recent prostate manipulation, prostatitis, and those on hormone therapy were excluded.

The researchers weighted and performed a multivariate linear regression to determine the effect on PSA measurements of the 10 most commonly prescribed medication classes. They adjusted for potential confounders including demographics, clinical characteristics, physical examination, laboratory studies, and duration of medication use.

In total, 1,864 men met inclusion criteria. They found that:

1- Nonsteroidal anti-inflammatory drug (NSAID; P = .03), statin (P = .01), and thiazide diuretic (P = .025) intake was inversely related to PSA levels.

2- Five years of NSAID, statin, and thiazide diuretic use was associated with PSA levels lower by 6%, 13%, and 26%, respectively.

3- The combination of statins and thiazide diuretics showed the greatest reduction in PSA levels: 36% after 5 years.

4- Concurrent calcium channel blocker use minimizes or negates the inverse relationship of statin use and PSA level.

They concluded that m