Daily phosphodiesterase type 5 inhibitor therapy: a new treatment option for prostatitis/prostatodynia?

40 T he management of patients with chronic pelvic pain attributed to chronic prostatitis has always been rather unsatisfactory. Even prolonged treatment with an aminoquinolone, such as ciprofloxacin, and an anti-inflammatory agent, or, alternatively an alpha-blocker, seldom results in rapid resolution of the symptoms, and is commonly completely ineffective. There is in fact a very reasonable rationale for the use of a long-acting phosphodiesterase type 5 (PDE5) inhibitor in the treatment of men with symptoms of abacterial prostatitis/prostatodynia. The underlying cause of these symptoms has long been a source of speculation. In the absence of an identifiable infective agent, the current widespread use of antibiotics as a treatment option defies logic. Over 30 years ago, Kirby et al. 1 suggested that intraprostatic reflux of urine might be an important initiating factor. In 2007, Grimsley et al. 2 suggested that PDE5 inhibitors might relax the smooth muscle in the prostatic ducts and thereby have a role in the management of prostatitis, but provided no evidence for the hypothesis. We recently encountered a patient, effectively disabled by prostatodynia, unresponsive to standard treatment, who had been taking morphine to control the pain from 2001 to 2008. He was unable to tolerate non-steroidal anti-inflammatory drugs. In 2008, he was prescribed initially 10mg, then 20mg daily, of the PDE5 inhibitor tadalafil, with immediate marked improvement of his symptoms. On cessation of the medication on four separate occasions, his symptoms returned; recommencement of treatment each time, with 5mg tadalafil daily, has resulted in similar persisting improvement of his symptoms, and he has been able to discontinue treatment with morphine. As a direct consequence of the conversation with this individual, we have prescribed tadalafil 5mg daily in several of our patients with prostatitis; so far with uniformly beneficial results. The longer-acting PDE5 inhibitor tadalafil has been proven in randomised controlled trials to be effective in the treatment of erectile dysfunction. 3 In addition, it has been shown to have a beneficial impact on lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia, who also often suffer from concomitant difficulties with erections. 4 Recently a meta-analysis of 17 trials has confirmed that tadalafil also significantly improves ejaculatory function. 5 In addition to the symptom of pelvic pain, men with chronic abacterial prostatitis/prostatodynia also frequently complain of associated LUTS and ejaculatory discomfort. Consequently treatment with tadalafil at a dose of 5mg/day for a period of time would …