Adverse Effects and Safety of 5-Alpha Reductase Inhibitors
(Finasteride, Dutasteride): A Systematic Review.
Reasons for the current stagnation of progress include failure of the Selenium and Vitamin E Cancer Prevention Trial (SELECT) to show preventive activity of selenium and vitamin E; the failure of a high-risk phase III study to show preventive activity of selenized yeast; the refusal of the Food and Drug Administration to approve finasteride for prostate cancer prevention; and uncertainty regarding the long-term effects of treatment with 5-alpha reductase inhibitors
, according to Dr.
As we stated earlier, 5-alpha reductase inhibitor
drugs like finasteride (Proscar[R]) and dutasteride (Avodart[R]), markedly shrink prostate gland volume, thus making detection of tumors much more efficient.
Two major studies have found that drugs known as 5-alpha reductase inhibitors
(5-ARIs)--dutasteride (Avodart[R]) and finasteride (Proscar[R])--may help lower a man's risk of prostate cancer.
In PCPT, the use of the 5-alpha reductase inhibitor
finasteride (Proscar) initially led to a 25% reduced risk of prostate cancer, but the medication also was associated with an increased risk of high-grade tumors.
The PCPT found an overall 25% relative risk reduction for prostate cancer in men who took the 5-alpha reductase inhibitor
finasteride for 1-7 years.
Half of the respondents indicated they would try an alpha-blocker alone, one-third would initiate an alpha-blocker in combination with an anti-inflammatory, 11% would recommend triple therapy with an alpha-blocker, anti-inflammatory and 5-alpha reductase inhibitor
, and 6% would initiate neuromodulatory therapy (e.
Schellhammer has received research funds or support from Glaxo-SmithKiine, which markets the 5-alpha reductase inhibitor
dutasteride, and from other pharmaceutical companies.
We believe men with these precancerous conditions would be candidates for 5-alpha reductase inhibitor
chemoprevention," he says.
Alpha blocker therapy can be withdrawn in the majority of men following initial combination therapy with the dual 5-alpha reductase inhibitor
Ask your doctor these questions before using a 5-alpha reductase inhibitor
(5-ARI) to prevent prostate cancer:
Researchers also are awaiting results from a four-year study to determine whether another 5-alpha reductase inhibitor
, dutasteride (Avodart), also prevents prostate cancer.
Finasteride (Proscar[R], Propecia[R]) and dutasteride (Avodart[R]) are in a class of medications called 5-alpha reductase inhibitors
because they block the effects of the enzyme and prevent the conversion of testosterone to DHT, but they don't reduce testosterone levels.
Although medical treatment of BPH with alpha blockers and 5-alpha reductase inhibitors
may ameliorate the urinary symptoms, surgical intervention may be inevitable in some patients.
8] Two studies have shown that 5-alpha reductase inhibitors
(5ARIs) reduce the risk of prostate cancer.