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REVIEW
SA JOURNAL OF DIABETES & VASCULAR DISEASE
60
VOLUME 8 NUMBER 2 • JUNE 2011
facilitating bladder emptying when a hypotonic or atonic bladder
is the problem.
34
For impaired or absent detrusor muscle activity,
intermittent self catheterisation is recommended, with the residual
volume being maintained at less than 400 cm
3
to avoid UI.
32
Pharmocological treatment
The mainstay of treatment for patients who present with urge UI
(OAB) are anti-muscarinic agents. They act by inhibiting the binding
of acetylcholine to the muscarinic receptors in the bladder smooth
muscle and reducing the involuntary detrusor muscle contractions
without disturbing normal voiding. However, the side-effect profile
of these drugs creates problems in terms of compliance. Side
effects include dry mouth, blurred vision, somnolence, dizziness
and cognitive problems.
Both immediate-release (IR) and extended-release (ER) formu-
lations of these drugs are available. Tolterodine and oxybutinin IR
and ER preparations have been shown to be safe and efficacious.
Oxybutinin IR may not be as well tolerated as the others however.
35
Newer agents such as solefenicin have similar efficacy to the older
agents, with the ER form showing better efficacy and safety.
36
Trospium chloride, an anticholinergic with predominantly peripheral
actions and minimal central nervous system side effects, may
be considered as an alternative for patients who do not tolerate
oxybutinin well.
37
Tricyclic antidepressants such as Imipramine may be used in the
treatment of OAB. The re-uptake of noradrenalin and serotonin are
inhibited by these drugs, resulting in increased contractile effects
of noradrenalin on urethral smooth muscle and enhanced detrusor
muscle relaxation, hence increasing storage function and functional
capacity.
38
However, serious side effects may preclude its use.
Drug therapy has a limited role in treating detrusor areflexia.
Parasympathomimetic agents have been used but their side effects
(sweating, salivation, tachycardia and flushing) preclude their daily
use. Bethanechol may be useful in patients with large residual
volumes (100–500 ml). Its selective actions on the bladder have
resulted in it being used to facilitate reflex contractions in patients
with spinal cord injury.
39
Thebenefits of oestrogen in the treatment of UI is questionable.
40,41
Although oestrogen therapy may improve urge UI, there is a risk of
malignancy and vascular consequences with long-term use.
42
One
study showed that postmenopausal estrogen therapy failed to cure
stress UI but did prevent recurrent urinary tract infections.
43
Duloxetine, a new selective serotonin and norepinephrine
reuptake inhibitor has demonstrated efficacy in the treatment of
stress UI. Inhibition of the reuptake of norepinephrine and serotonin
increases pudendal nerve activity and sphincter muscle tone.
44
Surgical treatment
If behavioral and pharmacological treatments fail for stress UI,
surgical therapy is possible, the aim of which is to reduce the risk
of infection. Some of the most common surgical options are listed
in Table 4.
Historically, transurethral bladder neck resection, leaving the
external sphincter intact to preserve continence, was advocated for
an acontractile bladder. However this may lead to cystourethrocele
formation in women and there may be pre-existing external
sphincter compromise due to diabetic neuropathy, resulting in
UI.
45,46
Outlet obstruction may be reduced by unilateral pudendal
neurectomy.
34
Sacral neuromodulation is another option for OAB. In this
method, the S3–S4 nerve roots are stimulated by a pacemaker. A
study involving diabetic patients has shown a success rate of 69%;
2% for urge UI, 85.7% for urgency–frequency, and 66.7% for
those with urinary retention.
47
However the diabetic patients had
a higher incidence of device expulsion due to infection (37.5 vs
25.5%).
Conclusion
UI associated with DM is relatively common and can have different
manifestations. Urodynamic evaluation is the cornerstone
Figure 1.
An algorithmic approach to treatment.
Voiding dysfunction
Evaluation
Medical history
Physical examination
Urodynamics
Disorder of storage
Disorder of emptying
Due to the outlet
Due to bladder
Physiotherapy
Pharmacotherapy
Periurethral injection
Intermittent catheterisation
Sling insertion
Behaviour modification
Pharmacotherapy
Neuromodulation
Intermittent catheterisation
Due to the outlet
Due to bladder
