保列治（波斯卡,Proscar）與鋸棕櫚的比較（英文版）

Library of Clinical Studies & Publications

Saw palmetto extract vs. Proscar

Proscar
Description: Proscar (finasteride) was the first FDA-approved drug in the treatment of BPH. It works by inhibiting the activity of an enzyme, 5 alpha-reductase, involved in male sex hormone (testosterone) metabolism. Proscar blocks the transformation of testosterone to hihydrotestosterone, a very potent hormone derived from testosterone, within the prostate. Dihydrotestosterone is responsible for the overproduction of prostate cells which ultimately results in prostate enlargement.

Effectiveness and safety:
Although Proscar has received much attention, based on the results of the clinical trials, less than 37% of patients on Proscar will experience clinical improvement after taking the drug for one year and it must be taken for at least six months before any improvement can be expected. Meanwhile, about 5% of men suffer from decreased libido, ejaculatory disorders, and impotence while on the drug. Despite Proscar`s shortcomings and side effects, Merck, the manufacturer of Proscar, has predicted sales will soon reach $1 billion dollars annually.

Cost
Proscar costs about $75.00 for a month`s supply

Saw Palmetto Extract
Description
The Saw palmetto extract used in the clinical studies is a well-defined purified fat-soluble extract containing between 85% and 95% fatty acids and sterols. Like Proscar, the therapeutic effect of the Saw palmetto extract appears to be due to its inhibition of dihydrotestosterone. However, the Saw palmetto extract also inhibits the binding of dihydrostestosterone at cellular binding sites.

Effectiveness and safety:
Numerous double-blind clinical studies on the Saw palmetto extract have shown it to be effective in nearly 90% of patients usually in a period of 4 to 6 weeks. Detailed toxicity studies in animals, as well as the results from clinical trials, indicate that the Saw palmetto extract is without toxicity or side effect. Despite the impressive clinical effectiveness, safety, and popularity of Saw palmetto extract in the treatment of BPH in the United States, manufacturers are prohibited from making any medical claims by the FDA.

Cost
At the effective dosage of 160mg twice daily, Saw palmetto extract costs about $24.00 for a month`s supply.

An extract of the berries from the Saw palmetto (Serenoa repens), a palm tree native to the Southern Atlantic coast, has emerged as a popular treatment for an enlarged prostate both in Europe and the United States. This popularity is for good reason.
Over 20 double-blind, placebo controlled studies have demonstrated the fat-soluble extract of the Saw palmetto berries is very effective in relieving all of the major symptoms of benign prostatic hyperplasia (BPH) including increased nighttime urinary frequency, the most bothersome complaint.
In fact, in these studies, the Saw palmetto extract has been shown to exert superior benefits compared to Proscar, the standard prescription drug used in the medical treatment of BPH.
To illustrate Saw palmetto extracts`s superiority over Proscar, let`s look at the effect of both on the maximum urine flow rate, a good indicator of bladder neck obstruction due to an enlarged prostate. The information featured in Figure 1 below is based on pooled data on Saw palmetto extract from all clinical studies and pooled data on Proscar listed in the Physician`s Desk Reference.
Figure 2 features the clinical studies demonstrating the efficacy of Saw palmetto extract in the treatment of BPH.

Figure 1 - back
Saw palmetto vs. Proscar on urine flow rate
(milliliters per second)

	Saw palmetto extract	Proscar
Initial Measurement	9.53 ml/sec	9.6 ml/sec
3 months	13.15 ml/sec*	10.4 ml/sec
12 months	**	11.2 ml/sec
% increase	38% in 3 months	16% in 12 months

*Many studies on the Saw palmetto extract were less than 90 days; final measurements were calculated as 90 measurements.
**There are no long-term studies on Saw palmetto extract, yet the effect at 3 months (or less) is obviously superior to that of Proscar.

Figure 2 - back
Clinical studies demonstrating the efficacy of Saw palmetto* in BPH

Authors	Type of Study	No. of patients	Length of study	Results
Boccafoschi, et al	Double-blind	22	60 days	Significant difference for volume voided, maximum flow, mean flow, dysuria, nocturia
Cirillo, et al	Open	47	4 months	Significant difference for: dysuria, nocturia, urine flow
Tripodi, et al	Open	40	30-90 days	Significant difference for: dysuria, nocturia, volume of prostate, voiding rate, residual urine
Emili, et al	Double-blind	30	30 days	Significant difference for: number of voidings, strangury, maximum and mean urine flow, residual urine
Greca, et al	Open	14	1 to 2 months	Significant difference for: dysuria, perincal heaviness, nocturia, volume of urine per voiding, interval between two dumal voidings, sensation of incomplete voiding
Duvia, et al	Controlled trial vs. pygeum	30	30 days	Significant difference for voiding rate
Tasca, et al	Double-blind	30	31 to 90 days	Significant difference for: frequency, urine flow measurement
Cukier, et al	Double-blind	168	60 to 90 days	Significant difference for: dysuria, frequency, residual urine
Crimi, et al	Open	32	4 weeks	Significant difference for: dysuria, nocturia, flow measurement, residual urine
Champault, et al	Double-blind	110	28 days	Significant difference for: dysuria, nocturia, flow measurement, residual urine
Mattei, et al	Double-blind	40	3 months	Significant difference: dysuria, nocturia, residual urine