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Complementary and Alternative Medicine for Urological Symptoms (CAMUS) Clinical Trial


More than one-half of men 50 years of age or older have lower urinary tract symptoms associated with the development of benign prostatic hyperplasia (BPH). In the United States alone, BPH accounts for at least 1.7 million office visits per year, and annual health care costs for this condition have been estimated to exceed $4 billion. In addition, symptoms of BPH have been shown to have a significant negative impact on patient-reported quality of life and psychological well being. Symptoms include urinary frequency, urgency, slow stream, and nighttime voiding.

Increasingly, men with these symptoms are treating themselves with phytotherapies or plant therapies that are sold over the counter. Two of the most commonly used phytotherapies are Serenoa repens (saw palmetto) and Pygeum africanum; however, little is known about the long-term effects of these agents. In 1996, extract of the saw palmetto berry was the ninth most common herbal remedy sold in the United States; in 1997, it was the fifth most common herbal remedy. As the U.S. male population ages, the use of alternative therapies for BPH will likely continue to increase substantially.

Despite the widespread use of phytotherapeutic agents for BPH, most U.S. physicians are reluctant to discuss or recommend them because only a modest number of published reports have appeared in the peer-reviewed medical literature. Nonetheless, the literature that is available supports the hypothesis that these compounds may have some beneficial effects on BPH symptoms. A recent meta-analysis suggests that saw palmetto improves urinary flow-rate and nocturia in men with symptoms of BPH. However, the medical literature has no statistically significant reports of rigorously conducted clinical trials on the long-term effects (both beneficial and adverse) and on patient-reported outcomes.

The CAMUS Study

In response to the above concerns, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), along with the National Center for Complementary and Alternative Medicine (NCCAM) and the Office of Dietary Supplements (ODS,) established a research consortium in Fall 2002 to study the effects of these agents in men with BPH with a randomized, double-blind clinical trial called Complementary and Alternative Medicine for Urological Symptoms (CAMUS).

The objective of the CAMUS Trial is to determine whether Serenoa repens (saw palmetto) and/or Pygeum africanum prevent the clinical progression of BPH, as defined by the development of one of the following:

  • Acute urinary retention
  • Renal insufficiency (due to BPH)
  • Recurrent urinary tract infections or urosepsis
  • New urinary incontinence
  • An increase in the American Urological Association (AUA) Symptom Score Index of four or more points
  • Cross-over to invasive or medical therapy for BPH
This definition of the clinical progression of BPH is identical to that used in the NIDDK-supported clinical trial, Medical Therapy of Prostatic Symptoms (MTOPS).

The efficacy of the two phytotherapies will be compared to a placebo. An active comparator arm containing an alpha blocker will be included. The clinical trial will randomize approximately 3,000 men age 45 and above with BPH over a two-year period. The men will be followed for a minimum of four years and a maximum of six years post-randomization.

The CAMUS clinical trial is currently in the design and planning stages. Recruitment is anticipated to begin in summer 2004. Ten clinical centers will participate in the trial. They are located at: Columbia University, NY, NY; New York University, NY, NY; University of Texas Southwestern Medical Center, Dallas, Texas; University of Colorado, Denver, CO; Washington University, St. Louis, MO; Yale University, New Haven, CT; Queens University, Hamilton, Ontario, Canada; Northwestern University, Chicago, IL; University of Maryland, Baltimore, MD; University of California at San Francisco, San Francisco, CA.

The website for the CAMUS study is

Project Officer: Leroy Nyberg, M.D., Ph.D., 301-594-7717

Last Update: 3/22/2004

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