© The Canadian Journal of Urology™; 21(Supplement 2); June 2014
20
Rosenberg ET AL.
TABLE 5.
Medications for benign prostatic hyperplasia/lower urinary tract symptoms (BPH-LUTS)
Drug
Brand name
Dose
Dosing
Indications
Alpha-blockers - non uroselective
Terazosin
Hytrin
1 mg-10 mg
Daily
BPH
Doxazosin
Cardura
1 mg-8 mg
Daily
BPH
Alpha-blockers - uroselective
Alfuzosin
Uroxatral (US)
10 mg
Daily
BPH
Xatral (Canada)
Silodosin
Rapaflo
8 mg
Daily
BPH
Tamsulosin
Flomax (US)
0.4 mg
Daily
BPH
Flomax CR (Canada)
Phosphodiesterase 5 inhibitors
Tadalafil
Cialis
2.5 mg (US)
Daily
BPH
Tadalafil
Cialis
5 mg
Daily
BPH and ED
Antimuscarinics - immediate release (IR)
Oxybutynin IR
Ditropan
5 mg
2-4 x/day
OAB
Tolterodine IR
Detrol
1 mg-2 mg
Twice daily OAB
Trospium chloride
Sanctura (US)
20 mg
Twice daily OAB
Trosec (Canada)
Antimuscarinics - extended release (ER)
Darifenacin ER
Enablex
7.5 mg, 15 mg
Daily
OAB
Fesoterodine ER
Toviaz
4 mg, 8 mg
Daily
OAB
Oxybutynin ER
Ditropan XL
5 mg-30 mg
Daily
OAB
Oxybutynin TDS
Oxytrol
3.9 mg = 1 patch
Twice weekly OAB
Oxybutynin 10% gel
Gelnique
100 mg = 1 g of gel
Daily
OAB
Solifenacin
Vesicare
5 mg, 10 mg
Daily
OAB
Tolterodine ER
Detrol LA
2 mg-4 mg
Daily
OAB
Trospium chloride
Sanctura XR (US)
60 mg
Daily
OAB
Beta 3 agonists
Mirabegron
Myrbetriq
25 mg, 50 mg
Daily
OAB
5 alpha reductase inhibitors
Dutasteride
Avodart
0.5 mg
Daily
BPH
Finasteride
Proscar
5 mg
Daily
BPH
the United States, Canada and Europe, only tadalafil
is approved for this,
36-40
Table 5. Although the exact
mechanism of action is unknown, it is believed that the
PDE5i increase the signaling of theNO/cGMPpathway,
which, in turn, reduces smoothmuscle tone in the lower
urinary tract.
41
It is reasonable to believe that the PDE5i
may also increase blood flow and oxidation to the
prostate and pelvic organs.
The male with BPH and no erectile function
concerns is fine to be treated with either and therefore
availability and cost are the differentiating factors.
However, the male with BPH and any degree of ED
could benefit from a medication that could treat both
situations. In a study published in 2012, Oekle et
al compared tadalafil and tamsulosin in a placebo
controlled study. They noted statistically significant,
yet similar, improvements versus placebo in BPH-
LUTS as early as 1 week which was sustained for
the 12 week study period. They also noted similar
improvement in urinary flow with both medications
through 12 weeks, although it should be noted that this
was the first study to demonstrate an improvement of
flow with the PDE5 drug class. The most significant,
yet expected, difference was that tadalafil improved
ED.
42
Common side effects of the PDE5i include
headache, back pain, dizziness and dyspepsia. They
are contraindicated in patients who use nitrates,
and should be used with caution in patients treated
with alpha-blockers, since the combination may
lead to hypotension. Tadalafil should not be used
