Medication Summary
The goals of pharmacotherapy are to create continence, reduce
morbidity, and prevent complications.
Anticholinergics, Genitourinary
Class Summary
Anticholinergic medications (eg, oxybutynin,
hyoscyamine, tolterodine) may be given to decrease detrusor instability and
symptoms of urgency. Intermittent catheterization and anticholinergic
management are usually used in combination to accomplish symptom-management
goals, to create continence, to eliminate vesicoureteral reflux, to prevent
UTIs, and to ensure low bladder-storage pressure. If these measures fail,
augmentation cystoplasty should be considered.
Oxybutynin chloride, a tertiary amine muscarinic receptor
antagonist, is a nonspecific relaxant on smooth muscles.
Tolterodine is a competitive muscarinic
receptor antagonist for overactive bladder. It differs from other
anticholinergics by being selective for the urinary bladder over the salivary
glands. Tolterodine has high specificity for muscarinic receptors and has
minimal activity or affinity for other neurotransmitter receptors and other
potential targets (eg, calcium channels).
Propantheline blocks the action of
acetylcholine at postganglionic parasympathetic receptor sites.
Hyoscyamine blocks the action of
acetylcholine at parasympathetic sites in smooth muscle, secretory glands, and
the CNS, which, in turn, has antispasmodic effects. Hyoscyamine is absorbed
well by the GI tract. Food does not affect absorption of this drug. Hyoscyamine
is available in sublingual form (Levsin SL, Symax SL), conventional tablets
(Levsin), and extended-release tablets (Levbid).
Neuromuscular Blockers, Botulinum Toxins
Class Summary
Agents in this class cause presynaptic paralysis of the myoneural
junction and reduce abnormal contractions.
OnabotulinumtoxinA injections are used in
some patients with overactive bladders and may benefit bladder-augmentation
candidates. Botulinum toxin may provide relief of spasticity without the
systemic adverse effects of other antispasticity agents. It binds to receptor
sites on the motor nerve terminals and, after uptake, inhibits the release of
acetylcholine, blocking transmission of impulses in neuromuscular tissue.
In treating adult patients for 1 or more
indications, the maximum cumulative dose generally should not exceed 360 U in a
3-month period. The recommended treatment dose of onabotulinumtoxinA is 200 U
per treatment, divided into 30 injections of 1 mL.