Prostasol and venous thromboembolism.
OBJECTIVE
To create physician awareness of complementary and alternative medicine therapy use in patients with prostate cancer so that physicians can monitor for adverse events. Approximately one fourth to one third of patients diagnosed with prostate cancer reported complementary and alternative medicine use, and many of these patients are taking a supplement called "Dr. Donsbach's Prostasol."


METHODS
We discuss the cases of 2 patients with prostate cancer who were taking Dr. Donsbach's Prostasol and developed venous thromboembolic events while taking this supplement, in the absence of other obvious risk factors. We review these 2 cases and the time-line for the development of the venous thromboembolic events and use of Dr. Donsbach's Prostasol. We compared Prostasol with PC-SPES, a similar supplement that was associated with thrombosis and was ultimately taken off the market because of patient safety concerns.


RESULTS
Prostasol contains phytoestrogens that could result in both the suppression of testosterone and the predisposition to thrombosis. Both patients had suppression of their testosterone to castrate levels with an associated decrease in prostate-specific antigen at the time of their thrombotic event.


CONCLUSIONS
These cases are suggestive of an association between Prostasol use and venous thromboembolic events. Physicians should be aware of the use of this agent in their patients, although it is not known whether it would be appropriate to prescribe prophylactic low-dose warfarin therapy. If possible, additional study of complementary and alternative medicine therapies for safety and efficacy are indicated.
Clement
Jessica
J
Division of Hematology-Oncology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA. jclement@bidmc.harvard.edu
Bubley
Glenn
G
D000368:Aged; D000369:Aged, 80 and over; D000529:Complementary Therapies; D019587:Dietary Supplements; D004365:Drugs, Chinese Herbal / Q000009:adverse effects*; D017984:Enoxaparin / Q000494:pharmacology; D006801:Humans; D008297:Male; D008495:Medical Oncology / Q000379:methods; D048789:Phytoestrogens / Q000627:therapeutic use; D028321:Plant Preparations / Q000009:adverse effects; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D054556:Venous Thromboembolism / Q000209:etiology*; D020246:Venous Thrombosis / Q000209:etiology; D014859:Warfarin / Q000494:pharmacology
D004365:Drugs, Chinese Herbal; D017984:Enoxaparin; D048789:Phytoestrogens; D028321:Plant Preparations; C114209:herbal preparation PC-SPES; D014859:Warfarin