Every man over a certain age knows about “the little blue pill” or the major brands Viagra, Cialis and Levitra. These medications are part of a class of drugs called PDE5 inhibitors, which are the first effective oral products to treat erectile dysfunction (ED).

ED is a problem that commonly occurs as men get older. It can also be related to cardiovascular disease, low testosterone, diabetes, and psychological problems. PDE-5 inhibitors help increase blood flow into the blood vessels of the penis during sexual stimulation. (The drugs have no effect in the absence of sexual stimulation.)

ED can also occur as a result of prostate cancer (PCa) treatment, especially radical prostatectomy. Any whole gland treatment (surgery, radiation, cryotherapy, HIFU) can damage the nerves that control erection because of their location adjoining the sides of the gland. If ED occurs as a result of PCa treatment, PDE5 inhibitors are almost always prescribed starting at a low dose in hopes of waking Mother Nature up again. Here are 4 questions (and answers) that you should know.

1. Can PDE5 pills cause prostate cancer?

For men with no PCa history, there is no evidence that PDE5 inhibitors will cause it.[i] Viagra, Cialis and Levitra are considered among the safest medications on the drug market. Side effects that have been reported include headaches, flushing, congestion, and erections lasting more than 4 hours, but these and others are infrequent. For men with certain risk factors for high blood pressure, diabetes, and high cholesterol, doctors may use caution in prescribing PDE5 inhibitors.

2. What about if I already had prostate cancer and went through treatment?

This question basically asks if PDE5 inhibitors can increase the chance that PCa will come back. Most of the evidence suggests that no, there is no greater risk of recurrence. For example, a recent study from the 2018 American Urological Association meeting used a very large Swedish database to statistically analyze PCa patients who used the pills after treatment vs. those who did not. The authors concluded there was no reason to believe that recurrence risk was higher. Also, another demographic study from the same meeting found that use of PDE5 inhibitors “was not associated with biochemical recurrence following treatment for prostatectomy or radiation therapy.”[ii] The authors even found a small (but statistically insignificant) hint that those who used the medication had less chance of recurrence.

3. So, there’s no need to worry about using PDE5 inhibitors after prostate cancer treatment?

Well, that’s not entirely true. The two presentations mentioned above were both drawn from banked information about thousands of men from many different centers. In other words, the statistical analysis drawn from information entered in patient records showed a clear trend. However, another type of study based on ongoing observation of patients from a single highly-respected European clinic came to a conclusion that “astonished” doctors.[iii] This earlier study followed 4752 consecutive patients treated between 2000-2010 at the Martini-Clinic Prostate Cancer Center (Hamburg, Germany).[iv] Average personal follow-up was 5 years. Within that period, 16% of those who used the pills after treatment had PSA evidence of suspected recurrence vs. 11% of those who did not. This difference was statistically significant, even after correcting for possible confounders. The authors acknowledge that more study is needed, but this paper suggests the importance of closer monitoring for post-treatment PDE5 users.

4. I have ED after prostate cancer treatment – what should I do?

You should discuss with your own doctor the benefits vs. risks of PDE5 inhibitors as well as other ED treatments such as injections or vacuum erection devices. If your cancer was low-risk before treatment, you and your doctor may agree that starting with a low dose of Viagra, Cialis or Levitra is a reasonable course of action.

On the other hand, if you are at risk for prostate cancer or have been recently diagnosed, we recommend that you have a 3T multiparametric MRI of the prostate before making a treatment decision. You may qualify for a focal therapy such as Focal Laser Ablation, which has minimal-to-no risk of urinary and sexual side effects.

There is much reason for optimism in the clinical world of prostate cancer. With ongoing improvements in detection and diagnosis, matching the treatment to the disease is a more refined and effective process than ever before in history. The Sperling Prostate Center is a global leader in treating qualified patients in a way that successfully controls cancer while preserving quality of life. Contact our Center for more information.  

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[i] Machen GL, Rajab MH, Pruszynski J, Coffield KS. Phosphodiesterase type 5 inhibitors usage and prostate cancer: a match-paired analysis. Transl Androl Urol. 2017 Oct; 6(5): 879-882.

[ii] Susman, Ed. “No Let Down: Viagra Does Not Increase Prostate Cancer Recurrences.” Reported in Oncology Times. https://journals.lww.com/oncology-times/Fulltext/2016/02250/No_Let_Down__Viagra_Does_Not_Increase_Prostate.8.aspx

[iii] Mulchay, Nick. “Docs ‘Astonished’: ED Drugs Tied to Prostate Cancer Return.”Reported in Medscape News, Jan. 15, 2017. https://www.medscape.com/viewarticle/838783#vp_2

[iv]Michl U, Molfenter F, Graefen M, Tennstedt P et al. Use of phosphodiesterase type 5 inhibitors may adversely impact biochemical recurrence after radical prostatectomy. J Urol. 2015 Feb;193(2):479-83.