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2017; 63(2):95-99
(18.2% using combined therapy vs. tamsulosin alone
[p<0.05] and vs. phytotherapy alone [p<0.05]).
3
(
A
)
Alpha-blockers
These are involved in the regulation of smooth muscle
tone of prostate and bladder neck, and are critical me-
diators of lower urinary tract symptoms and the patho-
physiology of BPH-LUTS. For this reason, alpha-blockers
are first-line drugs in the treatment of BPH symptoms.
3
(
A
) Alpha-blockers currently available: doxazosin, tam-
sulosin, alfuzosin, terazosin and silodosin, the last one
not available in Brazil. Although there are small differ-
ences between alpha-blockers, they are all equally effective
and lead to a 4- to 6-point objective drop in I-PSS, enough
for most patients to report significant improvement in
symptoms. These are considered to be very efficient drugs
as monotherapy in the treatment of BPH-LUTS.
4,5
(
A
)
Patients candidate for monotherapy with alpha-blockers
are mainly those with moderate to severe LUTS and with
an impact on quality of life. Symptomatic improvement
is perceived by the patient within four weeks and may
extend over a long period.
3
(
A
) Alpha-blockers are effective
in the treatment of BPH-LUTS, but their mechanism of
action does not prevent disease progression, only relief
of symptoms.
4,5
(
A
) The most common side effects of
alpha-blockers are asthenia, dizziness and orthostatic
hypotension.
5
(
A
) Ejaculatory dysfunction (retrograde
ejaculation, reduction of seminal ejaculated volume) is
frequently reported by patients.
6
(
A
)
5-alpha-reductase inhibitors (i5ARs)
There are currently two drugs that act by inhibiting
5AR: finasteride and dutasteride. Finasteride is a selec-
tive inhibitor of type II isoenzyme, whereas dutasteride
is a non-selective inhibitor, affecting type I and II iso-
enzymes. i5ARs may be prescribed to men with lower
urinary tract symptoms and enlarged prostate (> 40
mL) or high prostate-specific antigen (PSA) levels (> 1.6
ng/mL) and may prevent disease progression, reducing
both the need for surgery and acute urinary retention.
4,7-10
(
A
)
11
(
B
) One limitation to the use of monotherapy with
i5ARs is the onset of action: improvement of BPH-LUTS
takes between 4 and 6 months of therapy. Finasteride
and dutasteride have similar efficacy in reducing pros-
tate volume and improving urinary symptoms in BPH.
12
(
B
) The most relevant adverse effects include decreased
libido, erectile dysfunction and ejaculation disorders.
One to 2% of the patients develop gynecomastia (en-
largement of the breasts with increased breast or nipple
sensitivity).
13
(
A
)
Antimuscarinic drugs
These drugs have the property of inhibiting the action of
acetylcholine and thus reducing the contractility of the
detrusor muscle. Oxybutynin, tolterodine, darifenacin
and solifenacin are currently available in Brazil. Musca-
rinic receptor antagonists should be considered in men
with LUTS who have predominantly vesical storage symp-
toms.
14
(
A
) This class of drugs should be used with caution
in men with BPH and infravesical obstruction, especially
with high post-voidal residual volume, due to the possibil-
ity of incomplete emptying and the development of acute
urinary retention.
14
(
A
) Common side effects include dry
mouth, constipation, urinary difficulties, nasopharyngi-
tis, dizziness, confusion and restlessness.
Beta-3 agonists
Beta-3 agonists, a new class of drugs for treatment of blad-
der storage symptoms, stimulates the sympathetic system
during bladder filling, promoting relaxation of the detru-
sor muscle, increasing bladder functional capacity, decreas-
ing urinary frequency and urinary urgency episodes, as well
as urinary urge. Since it does not affect the parasympa-
thetic system, there is no interference in detrusor contrac-
tion and, thus, in the voiding process, which minimizes
the risk of urinary retention. Mirabegron, a beta-3 agonist,
did not adversely affect voiding urodynamics (maximum
urinary flow and detrusor pressure at maximum urinary
flow) compared with placebo after 12 weeks of treatment
in a double blind, placebo controlled study.
15
(A)
Combination therapy (antimuscarinic drugs and alpha-1 blocker)
Combination of anticholinergic drugs and alpha-1 blocker
may reduce storage symptoms and urinary frequency, ac-
cording to a long term study.
19
Although it can increase
the risk of acute urinary retention in patients with BPH
with baseline postvoid volume > 150 mL, the rate of acute
urinary retention is reduced in patients with postvoid vol-
ume < 150 mL, around 1%.
16-19
(
A
)
Combination therapy (alpha-blocker and i5AR)
The combination of alpha-blockers and i5ARs is an effective
treatment for patients with moderate to severe LUTS, in-
creased prostate volume (> 40 mL), high PSA (> 1.6 ng/mL),
and reduced maximum urinary flow. Combination thera-
py is valid not only for relief of symptoms but also to reduce
the risk of progression of BPH, it means increase of the
symptom score, surgical treatment due urinary retention,
urinary incontinence, urinary tract infection and renal
failure.
4,7-10
(
A
)
11
(
B
) It is not recommended for treatment
lasting less than one year and should be prescribed with