PDE5 inhibitors in prostate cancer: Could Viagra do more than treat ED?
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At this point, the broader benefits of PDE5i are still being studied, so they should still be discussed in terms of treating erectile dysfunction. They have a very good safety profile, and patients should not be nervous about trying them.
—Tony Chen, MD
Erectile dysfunction (ED) medications may have additional benefits for men with prostate cancer.
New research published in the World Journal of Men’s Health found that the drugs, known as phosphodiesterase 5 inhibitors (PDE5i), could offer benefits for comorbid conditions like enlarged prostate and difficulties with urination.[] The researchers also found improvements in other conditions, such as stroke, cardiovascular disease, diabetes, and even neurodegenerative conditions.
Related: ED drugs and systemic health: Could these medications offer broader benefits?“There is a large evidence base that supports the association of PDE5i with favourable clinical outcomes in several different health conditions that are also often considered co-morbidities for men with [prostate cancer]. We present this review to examine the evidence on favourable clinical outcomes associated with PDE5i use in a range of urological, cardiovascular, metabolic, and skeletal conditions. In men who have been treated for [prostate cancer], these co-morbidities are common and may even be exacerbated by treatment itself,” the study authors write.[]
Erectile dysfunction and prostate cancer
ED is common in men with prostate cancer, with more than 80% of prostate cancer patients reporting having poor or very poor erections.[]
“I would say certainly a man who's been treated for prostate cancer very often is going to have some sort of erection problem,” Alan Shindel, MD, a professor of urology at the University of California, San Francisco, tells MDLinx.
“We know that the treatments that exist for prostate cancer—prostatectomy, radiation therapy, androgen deprivation therapy—are very strongly linked to erectile dysfunction.” —Alan Shindel, MD
PDE5i are considered the first-line treatment for ED.
“I'm a proponent of the proactive approach to erectile dysfunction treatment in men with prostate cancer. In my practice, we start daily Cialis early in the treatment course, sometimes even before surgery or radiation takes place. PDE5i are an integral part of penile rehabilitation [and] prehabilitation protocols,” Tony Chen, MD, a clinical assistant professor of urology at Stanford University School of Medicine, tells MDLinx.
Dr. Chen notes that there are some important factors physicians should consider when prescribing this class of drugs.
“Nothing about a prostate cancer diagnosis specifically should dissuade a patient from using PDE5i for erectile dysfunction. The major factors that must be taken into account are cardiopulmonary comorbidities, such as recent myocardial infarction, stroke, or active use of medications like nitroglycerin. Some men with rare ophthalmologic diseases like retinitis pigmentosa should be counseled on risks [of] PDE5i.”
More research is needed to confirm the benefits
The research published in the World Journal of Men’s Health suggests that medications like Viagra could provide benefits for conditions other than ED, including heart conditions, diabetes, and stroke.[]
“In relation to the diabetes and cardiovascular trials … after adjusting for possible confounders, there was still a significant benefit in terms of mortality for the men on PDE5i. This is important because in men with low-grade cancer, CVD is the main cause of death, a fact that might be overlooked by specialist units managing men with prostate cancer and BPH,” the study authors write.
But the experts say more research is needed to support prescribing medications like Viagra for indications other than those currently approved by the FDA.
“At this point, the broader benefits of PDE5i are still being studied, so they should still be discussed in terms of treating erectile dysfunction. They have a very good safety profile, and patients should not be nervous about trying them—assuming they do not have any of the contraindications to the medication,” Dr. Chen says.