Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial.

CONTEXT: Saw palmetto fruit extracts are widely used for treating lower urinary tract symptoms attributed to benign prostatic hyperplasia (BPH); however, recent clinical trials have questioned their efficacy, at least at standard doses (320 mg/d). OBJECTIVE: To determine the effect of saw palmetto extract (Serenoa repens, from saw palmetto berries) at up to 3 times the standard dose on lower urinary tract symptoms attributed to BPH. DESIGN, SETTING, AND PARTICIPANTS: A double-blind, multicenter, placebo-controlled randomized trial at 11 North American clinical sites conducted between June 5, 2008, and October 10, 2010, of 369 men aged 45 years or older, with a peak urinary flow rate of at least 4 mL/s, an American Urological Association Symptom Index (AUASI) score of between 8 and 24 at 2 screening visits, and no exclusions. INTERVENTIONS: One, 2, and then 3 doses (320 mg/d) of saw palmetto extract or placebo, with dose increases at 24 and 48 weeks. MAIN OUTCOME MEASURES: Difference in AUASI score between baseline and 72 weeks. Secondary outcomes included measures of urinary bother, nocturia, peak uroflow, postvoid residual volume, prostate-specific antigen level, participants' global assessments, and indices of sexual function, continence, sleep quality, and prostatitis symptoms. RESULTS: Between baseline and 72 weeks, mean AUASI scores decreased from 14.42 to 12.22 points (-2.20 points; 95% CI, -3.04 to -1.36) [corrected]with saw palmetto extract and from 14.69 to 11.70 points (-2.99 points; 95% CI, -3.81 to -2.17) with placebo. The group mean difference in AUASI score change from baseline to 72 weeks between the saw palmetto extract and placebo groups was 0.79 points favoring placebo (upper bound of the 1-sided 95% CI most favorable to saw palmetto extract was 1.77 points, 1-sided P = .91). Saw palmetto extract was no more effective than placebo for any secondary outcome. No clearly attributable adverse effects were identified. CONCLUSION: Increasing doses of a saw palmetto fruit extract did not reduce lower urinary tract symptoms more than placebo. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00603304.

Redesigning a large-scale clinical trial in response to negative external trial results: the CAMUS study of phytotherapy for benign prostatic hyperplasia.

BACKGROUND: Benign prostatic hyperplasia (BPH), a common condition among older men, confers its morbidity through potentially bothersome lower urinary tract symptoms. Treatments for BPH include drugs such as alpha-adrenergic receptor blockers and 5-alpha reductase inhibitors, minimally invasive therapies that use heat to damage or destroy prostate tissue, and surgery including transurethral resection of the prostate. Complementary and alternative medicines are gaining popularity in the US. Two phytotherapies commonly used for BPH are extracts of the fruit of Serenoa repens, the Saw palmetto dwarf palm that grows in the Southeastern US, and extracts of the bark of Pygeum africanum, the African plum tree. PURPOSE: The objective of the Complementary and Alternative Medicines for Urological Symptoms (CAMUS) clinical trial is to determine if phytotherapy is superior to placebo in the treatment of BPH. METHODS: CAMUS was originally designed as a 3300-participant, four-arm trial of S. repens, P. africanum, an alpha-adrenergic blocking drug, and placebo with time to clinical progression of BPH, a measure of long-term efficacy, as the primary endpoint. Before enrollment started, a randomized, double-blind, placebo-controlled, single institution clinical trial showed that S. repens at the usual dose did not demonstrate any benefit over placebo with respect to symptom relief at 1 year. Consequently, the focus of CAMUS shifted from evaluating long-term efficacy to determining if any short-term (6-18 months) symptom relief could be achieved with increasing doses of S. repens, the phytotherapy most commonly used in the US for BPH. RESULTS: Results are anticipated in 2011. CONCLUSIONS: Trial design occurs in an environment of continually evolving information. In this case, emerging results from another trial suggested that a study of long-term efficacy was premature, and that an effective dose and preparation of S. repens had to be established before proceeding to a long-term clinical trial.