2009 update on phosphodiesterase type 5 inhibitor therapy part 2: updates on optimal utilization for sexual concerns and rare toxicities in this class.
BACKGROUND
Highly selective inhibitors of phosphodiesterase type 5 (PDE5I) have been commercially available for over a decade. Our knowledge of these drugs continues to expand.


OBJECTIVE
To review recent (since 2007) developments on the utilization of PDE5I in clinical practice. The focus of this manuscript is on the use of PDE5I for sexual concerns. Also reviewed are recent reports of rare but potentially serious toxicity.


METHODS
Pubmed search utilizing the search terms "phosphodiesterase type 5 inhibitor," "PDE5 inhibitor,""sildenafil," "vardenafil," and "tadalafil." Articles were screened for their relevance to the clinical practice of sexual medicine and/or PDE5I toxicity. Publications on routine dose PDE5I for penile rehabilitation, lower urinary tract symptoms, and stuttering priapism are summarized in a separate manuscript in this series.


METHODS
Peer-reviewed publications since the last major update on PDE5I published in the medical literature.


RESULTS
Recent investigations have suggested a number of interventions to potentially improve patient compliance with PDE5I therapy. Additionally, the approval in the past year of tadalafil as a daily medication signifies a potential paradigm shift in our concept of this disorder. Daily dosing may be useful in some men; however, the other available PDE5I continue to show excellent efficacy in the management of erectile dysfunction (ED). In addition to direct effects on ED, several recent reports highlight the use of PDE5I for improvement of premature ejaculation, sexual relationship status, and sexual function in women. There have also been several recent reports of rare but serious toxicity, particularly ototoxicity, associated with PDE5I use.


CONCLUSIONS
Recent studies have suggested new ways to optimize utilization of PDE5I not only for the management of ED but also for other sexual concerns in both men and women. Rare but serious toxicities have been reported with PDE5I and, therefore, judicious counseling is indicated before prescribing these medications.
Shindel
Alan W
AW
Department of Urology, University of California, San Francisco, CA 94143-0738, USA. shindela@urology.ucsf.edu
D002243:Carbolines / Q000009:adverse effects / Q000627:therapeutic use; D002987:Clitoris / Q000187:drug effects; D004502:Education, Medical, Continuing; D005260:Female; D006311:Hearing Disorders / Q000139:chemically induced; D006801:Humans; D007093:Imidazoles / Q000009:adverse effects / Q000627:therapeutic use; D018783:Impotence, Vasculogenic / Q000188:drug therapy*; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use; D011687:Purines / Q000009:adverse effects / Q000627:therapeutic use; D020018:Sexual Dysfunctions, Psychological / Q000188:drug therapy; D019529:Sexuality / Q000187:drug effects*; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000009:adverse effects / Q000627:therapeutic use; D000068581:Tadalafil; D014227:Triazines / Q000009:adverse effects / Q000627:therapeutic use; D000069058:Vardenafil Dihydrochloride
D002243:Carbolines; D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate