Saw palmetto extract: Newest (and oldest) treatment alternative for men with symptomatic benign prostatic hyperplasia (BPH)

The following abstract is taken from
an invited editorial opinion, published in full
in the February, 1999 issue of Urology.
Authors are Leonard S. Marks, M.D.
(USRF and UCLA Urology Dept.)
and Varro E. Tyler, Ph.D.
(School of Pharmacy, Purdue University).

Saw palmetto extract (SPE) should now be considered a treatment option for men with symptomatic BPH, absent complications of the disorder. SPE is extremely safe; it is likely to exert positive effects; many patients want it; and more potent remedies, i.e., drugs or surgery, are generally not required in most BPH cases. A recent meta-analysis of SPE trials from Europe (where nearly all previous studies originated) was published in a recent issue of the Journal of the American Medical Association concluding that SPE improves urinary flow and decreases prostate symptoms in men with BPH. The JAMA abstract is reproduced below.

SPE has been used in the treatment of BPH in Europe for generations, and the favorable European experience is the major impetus for current interest in the U.S. Ironically, the main source of saw palmetto is the southeastern United States, especially plantations in the state of Florida, where this indigenous plant was previously regarded as a weed and is now considered a "cash crop," according to a report in the Los Angeles Times (9/1/97). The 1998 Florida harvest is expected to yield an estimated 2000 tons of dried saw palmetto berries worth approximately $50 million to the growers, who will ship most of the product to Europe.

In the U.S., herbal products are regulated as dietary supplements, under the 1994 Dietary Supplement Health and Education Act (DSHEA). For a thorough understanding of current laws regulating herbal products in the U.S. the reader is referred to a pertinent website of the U.S. FDA.

The safety of saw palmetto extract (SPE) has never been seriously questioned. Aside from an occasional instance of gastrointestinal upset, side effects of saw palmetto extracts have not been reported. In particular, use of the extract has not been associated with erectile dysfunction, ejaculatory disturbance, or altered libido. However, pharmaceutical-style evaluations have not previously been performed in the U.S., partly because they are not required by law and partly because the cost of such evaluations would be difficult to recoup with this non-patentable product.

Very recently, such a SPE study was completed at USRF offices in Los Angeles.

Abstracts of the USRF study, the first U.S. randomized clinical trial of saw palmetto in men with symptomatic BPH, have been submitted for presentation at the upcoming annual meeting of the American Urological Association to be held in Dallas, TX in May, 1999.

Saw Palmetto Extracts for Treatment of Benign Prostatic Hyperplasia: A Systematic Review

Timothy J. Wilt, MD, MPH; Areef Ishani, MD; Gerold Stark, MD; Roderick MacDonald, MS; Joseph Lau, MD; Cynthia Mulrow, MD, MS
JAMA 280:1604-1609, 1998 (November 11, 1998)

OBJECTIVE -- To conduct a systematic review and, where possible, quantitative meta-analysis of the existing evidence regarding the therapeutic efficacy and safety of the saw palmetto plant extract, Serenoa repens, in men with symptomatic benign prostatic hyperplasia (BPH).

DATA SOURCES -- Studies were identified through the search of MEDLINE (1966-1997), EMBASE, Phytodok, the Cochrane Library, bibliographies of identified trials and review articles, and contact with relevant authors and drug companies.

STUDY SELECTION -- Randomized trials were included if participants had symptomatic BPH, the intervention was a preparation of S repens alone or in combination with other phytotherapeutic agents, a control group received placebo or other pharmacological therapies for BPH, and the treatment duration was at least 30 days.

DATA EXTRACTION -- Two investigators for each article (T.J.W., A.I., G.S., and R.M.) independently extracted key data on design features, subject characteristics, therapy allocation, and outcomes of the studies.

DATA SYNTHESIS -- A total of 18 randomized controlled trials involving 2939 men met inclusion criteria and were analyzed. Many studies did not report results in a method that permitted meta-analysis. Treatment allocation concealment was adequate in 9 studies; 16 were double-blinded. The mean study duration was 9 weeks (range, 4-48 weeks). As compared with men receiving placebo, men treated with S repens had decreased urinary tract symptom scores (weighted mean difference [WMD], -1.41 points [scale range, 0-19] [95% confidence interval (CI), -2.52 to -0.30] [n=1 study]), nocturia (WMD, -0.76 times per evening [95% CI, -1.22 to -0.32] [n=10 studies]), and improvement in self-rating of urinary tract symptoms; risk ratio for improvement (1.72 [95% CI,1.21-2.44] [n=6 studies]), and peak urine flow (WMD, 1.93 mL/s [95% CI, 0.72-3.14] [n=8 studies]). Compared with men receiving finasteride, men treated with S repens had similar improvements in urinary tract symptom scores (WMD, 0.37 International Prostate Symptom Score points [scale range,0-35] [95% CI, -0.45 to 1.19] [n=2 studies]) and peak urine flow (WMD, -0.74 mL/s [95% CI,-1.66 to 0.18] [n=2 studies]). Adverse effects due to S repens were mild and infrequent; erectile dysfunction was more frequent with finasteride (4.9%) than with S repens (1.1%; P<.001). Withdrawal rates in men assigned to placebo, S repens, or finasteride were 7%, 9%, and 11%,respectively.

CONCLUSIONS -- The existing literature on S repens for treatment of BPH is limited in terms of the short duration of studies and variability in study design, use of phytotherapeutic preparations, and reports of outcomes. However, the evidence suggests that S repens improves urologic symptoms and flow measures. Compared with finasteride, S repens produces similar improvement in urinary tract symptoms and urinary flow and was associated with fewer adverse treatment events. Further research is needed using standardized preparations of S repens to determine its long-term effectiveness and ability to prevent BPH complications.

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