Treating erectile dysfunction and central neurological diseases with oral phosphodiesterase type 5 inhibitors. Review of the literature.
BACKGROUND
Erectile dysfunction (ED) is reported in a high percentage of patients with central neurological disorders (CND).


OBJECTIVE
An up-to-date review on oral phosphodiesterase 5 inhibitors (PDE5): sildenafil, tadalafil, and vardenafil for individuals with CND and ED.


METHODS
Various questionnaires on ED, such as the International Index of Erectile Function composed of 15 questions.


METHODS
Internationally published clinical studies evaluating the efficacy and safety of PDE5 on subjects with CND and ED were selected.


RESULTS
Overall, 28 articles on PDE5 used to treat patients with CND and ED were included. With each of the three PDE5 compared to placebo or erectile baseline, literature reported significant statistical improvement (P < 0.01; P < 0.05) only in patients with spinal cord injury (SCI). PDE5 efficacy was documented for SCI patients up to 10 years. The most frequent predicable factor for PDE5 success was the presence of upper motoneuron lesion. Each of the three clinical sildenafil studies documented statistically significant improvement on erectile function in Parkinson's patients (P < 0.01; P < 0.05). Two studies reported discordant results about sildenafil's effectiveness on multiple sclerosis (MS) patients; one on tadalafil showed significant statistical efficacy on erection versus baseline (P < 0.01; P < 0.05). The only spina bifida article determined that sildenafil remarkably improved erectile function. Overall, drawbacks were mostly slight-moderate, except in subjects with multiple system atrophy where sildenafil caused severe hypotension.


CONCLUSIONS
PDE5 represent first line ED therapy only for SCI patients, though treatment results through meta-analysis were not possible. Encouraging results are reported for Parkinson's and MS patients. PDE5 use for other CND patients is limited for various reasons, such as ED and concomitant libido impairment caused by depression and/or sexual endocrinology dysfunctions, and because PDE5 may cause a worsening of neurological illness. Medical centers staffed by health professionals able to counsel patients on the possible use of PDE5 are needed.
Neuro-urology Department, University of Florence, Florence, Italy. giuseppelombardi@interfree.it
Giuseppe
G
Lombardi
Federico
F
Nelli
Maria
M
Celso
Marco
M
Mencarini
Giulio
G
Del Popolo
D002243:Carbolines / Q000009:adverse effects / Q000627:therapeutic use; D002493:Central Nervous System Diseases / Q000150:complications*; D002986:Clinical Trials as Topic; D006801:Humans; D007093:Imidazoles / Q000009:adverse effects / Q000627:therapeutic use; D018783:Impotence, Vasculogenic / Q000188:drug therapy*; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications; D010300:Parkinson Disease / Q000150:complications; D058986:Phosphodiesterase 5 Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D010879:Piperazines / Q000009:adverse effects / Q000627:therapeutic use; D011687:Purines / Q000009:adverse effects / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D016135:Spinal Dysraphism / Q000150:complications; D013450:Sulfones / Q000009:adverse effects / Q000627:therapeutic use; D000068581:Tadalafil; D016896:Treatment Outcome; D014227:Triazines / Q000009:adverse effects / Q000627:therapeutic use; D000069058:Vardenafil Dihydrochloride
D002243:Carbolines; D007093:Imidazoles; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate