© The Canadian Journal of Urology™; 23(Supplement 1); February 2016
or fistula. Urodynamics should be undertaken before
any invasive treatments are pursued for OAB.
The main role of further investigations is to exclude
an underlying cause for the symptoms. Imaging such
as plain x-ray and urinary tract ultrasound can be used
to exclude stones and bladder lesions.
Treatment
Treatment for OAB in both genders should take
a graded approach with the most conservative
measures attempted first. Any underlying medical
conditions should be managed and optimized
especially urinary tract infections, diabetes, cardiac
disease and constipation. Lifestyle modifications and
behavioral therapies should be embarked upon by
patients early andmaintained alongside various other
treatments. Weight loss, exercise, smoking cessation
and modification of fluid and caffeine intake can be
difficult for patients to successfully implement into
their lives, but these measures should be encouraged.
Behavioral therapy aims to teach patients to learn
bladder control and improve their symptoms. Timed
voiding and bladder retraining techniques can reduce
symptoms of frequency and urgency. Pelvic floor
physiotherapy is also important, especially in women.
Apart from very mild cases, pharmacotherapy is
much more efficacious than behavioral measures in
reducing symptoms and improving quality of life. The
ideal approach is to combine pharmacotherapy with
conservativemeasures to produce an optimal outcome.
A wide range of medical treatments are available
at the urologists’ disposal. Some gender differences
are apparent in our use of medical treatments for this
condition. The broad classes of drugs used to treat
OAB include anticholinergic or antimuscarinic agents,
desmopressin, tricyclic antidepressants, beta 3 agonists
and intravesical Botox injections.
17-20
Specifically in
men, the role of alpha blockers in conjunction with
anticholinergics has been extensively studied.
21,22
Male patients may also benefit from PDE5 inhibitors
for LUTS.
22
In resistant cases, sacral neuromodulation
and posterior tibial nerve stimulation have been trialed
with encouraging results.
17
End stage cases may need
to resort to augmentation enterocystoplasty but this
has now become exceedingly rare.
Anticholinergic medications
Antimuscarinic or anticholinergic agents are usually
the first line pharmacotherapy in OAB. They work by
blocking the effects of neurotransmitter acetylcholine
by binding to nicotinic and muscarinic receptors.
23
More selective anticholinergics have more affinity
for M2 and M3 receptors (the predominant receptors
in the bladder) and therefore may have a better side
effect profile. Antimuscarinics work by reducing
involuntary detrusor contractions, thereby reducing
symptoms of frequency and urgency. It also improves
bladder capacity. Traditional and more selective
anticholinergics are used in both men and women
with good results.
Some unique features of some of the anticholinergics
do exist. Darifenacin (Enablex) is highly specific for
M3 receptors. Although its effectiveness is comparable
to other OAB medications, its unique feature is its
lack of effect on cognitive function.
24,25
This is an
important issue in elderly patients that commonly have
OAB. One downside of this medication is its slightly
higher incidence of constipation as compared to other
anticholinergics.
23
Fesoterodine (Toviaz) is extensively hydrolyzed
by serum esterases to 5-HMT, being the same active
metabolite as tolterodine (Detrol). Unlike tolterodine,
fesoterodine is not metabolized by the liver, which
results in more consistent and predictable blood
levels.
23
Furthermore, two well designed trials have
shown that fesoterodine is effective and well tolerated
in the elderly and even in the fragile elderly with no
significant cognitive dysfunction.
26,27
Fesoterodine is
one of only three drugs that received a Fit for theAged
(FORTA) classification B or “beneficial” rating in the
oral drug treatment of lower urinary tract symptoms
in the elderly.
28
One particular concern in using anticholinergic
medications in men is the potential risk of acute
urinary retention (AUR), especially in men with co-
existing OAB and bladder outlet obstruction. The
safety and efficacy of anticholinergic medications used
alone or in combination with alpha blockers in men
with OAB has been reviewed in the literature. Abrams
et al studied the safety of tolterodine for the treatment
of OAB in men with bladder outlet obstruction.
21
This
study demonstrated that tolterodine was safe in men
with mild to severe bladder outlet obstruction who
also had urodynamically confirmed DO. It did not
precipitate urinary retention or worsen preexisting
LUTS with the incidence of adverse events being
comparable in both treatment and placebo groups.
Anticholinergic treatments appear to be safe and
effective in men with predominant OAB symptoms.
Combination therapy (anticholinergic drug and alpha
blocker) has been found to be more effective than
monotherapy in treating men with OAB.
18
According
to Kaplan et al, the incidence of AUR in men receiving
anticholinergic medications was low (< 3%) with no
significant changes in maximum flow rate or PVR
Eapen AND Radomski
6