By age 50, about 25% of men suffer from symptoms of an enlarged prostate, a condition known as benign prostatic hyperplasia, or BPH. By age 80, up to one third experience symptoms severe enough to require treatment for BPH from such medications as dutasteride (Avodart) and finasteride (Proscar). One question men should ask is, can BPH drugs cause sexual dysfunction?
According to Dr. Abdulmaged M. Traish, a professor of biochemistry and urology at Boston University School of Medicine, almost all men taking these drugs experience side effects. Unfortunately, a study by Dr. Traish finds that some sexual side effects may be long-term or even irreversible. BPH medications may cause the inability to have or maintain an erection (erectile dysfunction), decreased sexual desire, difficulty ejaculating, or decreased volume of ejaculate.
Both dutasteride and finasteride belong to a class of medications known as 5-alpha reductase inhibitors. These drugs work by blocking production of a male hormone called androgen that causes the prostate to enlarge. However, says Dr. Traish, “We need androgen for erectile function, libido, and ejaculation, and for just feeling good.”
For the study, which was published in the March issue of the Journal of Sexual Medicine, Dr. Traish and his team evaluated the available medical literature for reports of sexual side effects associated with BPH medications. About 8% of men reported erectile dysfunction and 4.2% reported reduced libido compared to 4% and 1.8%, respectively, of men taking a placebo. Dr. Traish notes that in a small percentage of cases, the symptoms persisted even after the medication was stopped.
Dr. Irwin Goldstein, the editor-in-chief of the Journal of Sexual Medicine says, “The growing use of 5-alpha reductase inhibitors is causing concerns.” More research is needed to better understand the potential side effects.
Men who experience severe side effects from either dutasteride or finasteride should talk with their physicians about options. Alpha-blockers such as tamsulosin (Flomax) may be an alternative. This drug works by relaxing the muscles in the prostate and bladder so that urine can flow easily and is often prescribed in combination with a 5-alpha reductase inhibitor.
PubMed Health. National Center for Biotechnology Information
Reinberg S. Sexual side effects from Propecia, Avodart may be irreversible. USA Today 2011 Mar
Savage S. Popular drugs for common male health problems can affect their sexual health. Red Orbit. 2011 Mar 7
Traish AM et al. Adverse side effects of 5a-reductase inhibitors therapy: persistent diminished libido and erectile dysfunction and depression in a subset of patients. Journal of Sexual Medicine 2011 Mar; 8(3)