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.
(3), (35) The authors of this new study emphasized that the reason that more men in the finasteride group were found with high grade disease was "detection bias." 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.
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.
The 5-alpha reductase inhibitors
are known to lower levels of dihydrotestosterone, which can contribute to prostate cancer growth.
"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Alpha blocker therapy can be withdrawn in the majority of men following initial combination therapy with the dual 5-alpha reductase inhibitor
Men taking drugs known as 5-alpha reductase inhibitors
(5-ARIs) to treat benign prostatic hyperplasia (BPH, or enlarged prostate) may face a modestly increased risk of type 2 diabetes compared with another type of BPH medication, recent evidence suggests.
Now there are three classes of medications: alpha blockers (Tamsulosin and others), 5-alpha reductase inhibitors
(Finasteride and others) and the phosphodiesterase-5 Inhibitor Tadalafil.
Adverse Effects and Safety of 5-Alpha Reductase Inhibitors
(Finasteride, Dutasteride): A Systematic Review.
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.
Dutasteride inhibits 5AR types 1 and 2.[sup.8] Two studies have shown that 5-alpha reductase inhibitors
(5ARIs) reduce the risk of prostate cancer.[sup.9,10] In men with benign prostatic hyperplasia (BPH), 5ARIs reduce serum prostate-specific antigen (PSA) levels by 50% to 66%.[sup.11,12]
There is a need for randomized controlled trials to analyze the efficacy and side-effects of combination therapy with PDE-5 inhibitors and 5-alpha reductase inhibitors
. Age, BMI and LUTS severity seem to be important parameters in determining the most appropriate candidates for PDE-5 inhibitor treatment.
The two main classes of BPH drugs: alpha blockers like Flomax and UroXatral, which relax the muscles of the bladder neck and prostate, and 5-alpha reductase inhibitors
like Proscar and Avodart, which lower levels of hormones produced by the prostate.
For men with significant enlargement, drugs called 5-alpha reductase inhibitors
(5-ARIs) are available to shrink the prostate.