Men who use the drug finasteride to treat an enlarged prostate may experience serious side effects, including worsening erectile dysfunction and decreased testosterone levels leading to hypogonadism, a condition in which there is little to no production of sex hormones.
Finasteride is also known as proscar and propecia. Men who used tamsulosin—known as Flomax—experienced none of the same adverse side effects.
Considerable controversy exists regarding the severity and persistence of the adverse effects of 5α reductase inhibitors (5α-RIs) such as finasteride. Many investigators believe that the side effects on sexual function affect only a small proportion of treated patients and resolve with continuing treatment.
Drop in total testosterone
For a new study, published online in the journal Hormone Molecular Biology and Clinical Investigation, researchers studied 470 men who were treated with finasteride and 230 men who received the alpha blocker tamsulosin for their BPH.
Both groups were followed for 45 months and were assessed for improvement of BPH symptoms. Prostate specific antigen and testosterone levels were also measured.
The effects of the drugs on the quality of life were assessed by the Aging Male Symptom scale while the effects of the drugs on erectile function were assessed by the International Index of Erectile Function.
Men treated with finasteride experienced marked and significant gradual decrease in their erectile function and had significant and progressive decline in total testosterone levels while those on the tamsulosin therapy did not.
Sexual function & overall health
Both drugs have been proven useful in treatment of lower urinary tract symptoms related to BPH.
“However, 5α reductase inhibitors exert undesirable sexual side effects and, in some cases, these effects are persistent,” says Abdulmaged M. Traish, professor of biochemistry and urology at Boston University School of Medicine.
“Since sexual function is considered an integral part of overall health, it is important that physicians are aware of the adverse side effects of this class of drugs on human health in general and on sexual function in particular. Our study emphasized that the effect on erectile function is a serious concern and needs to be considered more carefully.”
The Boston University School of Medicine’s urology department funded the work.
Source: Boston University