http://www.medscape.com/viewarticle/537510

"The Use of Phosphodiesterase-5 Inhibitors in the Treatment of LUTS
An exciting new development in the medical therapy of LUTS and BPH is
the use of phosphodiesterase inhibitors, specifically inhibitors of
the PDE-5 isoenzyme. These drugs, which are currently approved for the
treatment of men with erectile dysfunction, work by inducing
relaxation of the smooth muscle in the cavernous tissue of the penis.
It is known that there is a considerable abundance of PDE-5 also in
the prostate presumably involved in smooth muscle tone regulation as
well. It seemed plausible that inhibition of the PDE-5 in the prostate
might lead to smooth muscle relaxation by a mechanism similar to the
one postulated for alpha receptor blocker. Indeed, in addition to
other reports, there have been noncontrolled publications emphasizing
the improvement in LUTS symptoms in men treated with sildenafil
citrate for BPH.[7,8]

At this year's meeting, the results of 3 studies on the use of PDE-5
inhibitors for the treatment of BPH/LUTS were reported. Roehrborn and
coworkers[9] presented the results of a double-blind, randomized,
parallel-group study of the effect of tadalafil on men with LUTS due
to BPH. After a 4-week placebo run-in to evaluate treatment
compliance, the 281 men who met eligibility criteria were randomized
to receive either tadalafil 5 mg for 6 weeks followed by an escalation
to 20 mg for a further 6 weeks or placebo for 12 weeks. From the
screening visit to the endpoint, tadalafil improved the IPSS by 6.2
points (5 mg) and 7.1 points (20 mg) compared with a placebo effect of
3.9 and 4.5 points, respectively (Table). Improvements in quality-of-
life scores and BPH impact indices were similar for the tadalafil and
placebo groups. However, tadalafil surprisingly had no effects on
maximum urinary flow rate or postvoid residual. The drug, which was
well tolerated, had an additional beneficial effect -- a significant
improvement in the International Index of Erectile Function (IIEF)
score....

In a very similar trial,[10] sildenafil citrate was given in doses of
50 and 100 mg at bedtime or prior to sexual activity daily to 366 men
over the age of 45 with an IIEF score of less than 25 and IPSS of
greater than 12 points. The erectile function domain of the IIEF
improved by 9.2 in the sildenafil group vs 1.9 points in the placebo
group (P < .001), and the IPSS improved by 6.3 in the sildenafil group
vs 1.9 points in the placebo group. All other measures, such as BPH
impact index and quality-of-life score, were better in men receiving
sildenafil than in those on placebo (Figure 2). However, in this as
well as in the tadalafil study, no effect was seen on maximum urinary
flow rate."

Anyone tried it?

D