Avodart and Beta Sitosterol

[WESTYDOG]

Recently received information from Theralogix on Prostate SR. Interesting combination of two herbals. I am concerned with the effect or reaction Prostate SR has when taking Avodart or another 5 alpha reductase inhibitor?

Reason for this inquiry is the possible synergistic effect when both Avodart and beta sitosterol evidence a reduction of one or both isoenzymes of 5 alpha reductase?

Additionally, if Avodart artificially reduces PSA readings by approximately 50%, what is the effect on PSA levels if both are taken?

My concern is not specifically with the PSA reading, but the additive effect Avodart or Proscar may have when taken along with beta sitosterol. All releave urinary frequency and urgency by shrinking the prostate by reducing the level of 5 alpha reductase, so the question to respond to is the synergistic effect, or stated another way, is it redundant to take beta sitosterol AND another reductase inhibitor? If not, is this evidenced based, and where?

[theralogix]

Hello-

Thanks for your question. There have been several studies comparing saw palmetto (many have used Permixon, a European brand) and finasteride, a 5-alpha reductase inhibitor. It seems that saw palmetto does not decrease PSA level, and decreases prostate size only slightly, compared to 5-alpha reductase inhibitors, which decrease size and PSA level substantially. You may be interested in reading these abstracts-
http://www.ncbi.nlm.nih.gov/pubmed/7805711 (small open-label trial, saw palmetto did not decrease DHT levels)
http://www.ncbi.nlm.nih.gov/pubmed/8876706 (large trial- saw palmetto and finasteride improved urinary symptoms; saw palmetto decreased prostate volume only slightly and did not decrease PSA levels)
http://www.ncbi.nlm.nih.gov/pubmed/9759701 (saw palmetto did decrease DHT, indicating 5-alpha reductase inhibition)

Saw palmetto has also been compared to alpha-blockers (tamsulosin)-
http://www.ncbi.nlm.nih.gov/pubmed/12074791 (both decreased symptoms, saw palmetto did not decrease PSA, and decreased prostate volume slightly)
http://www.ncbi.nlm.nih.gov/pubmed/12189744

Mechanism of saw palmetto- http://www.ncbi.nlm.nih.gov/pubmed/15543614
http://www.ncbi.nlm.nih.gov/pubmed/15540722?dopt=Abstract

As for beta-sitosterol, I am not aware of it inhibiting 5-alpha reductase, and it has not been shown to shrink the prostate, but it has been shown to decrease urinary tract symptoms. We have links to PubMed abstracts on our web site- http://www.theralogix.com/index.cfm?fa=products.prostatesr.references&dvsn=urology#mn

I don't think there are studies showing whether using Avodart and these compounds together has an additive or synergistic effect. One study looked at the use of saw palmetto and an alpha-blocker, and showed that both decreased symptoms but together did not have an additive effect. http://www.ncbi.nlm.nih.gov/pubmed/17203353?dopt=AbstractPlus

I hope this information helps. Let me know if you have further questions.

Sincerely,
Tiffany Graham, MPH, RD, LD
VP for Research and Education
Theralogix, LLC