Drugs for Urinary Incontinence or Retention Flashcards
What does the treatment of urinary incontinence usually start with?
Behavioral therapy, including patient education, fluid management, bladder retraining, pelvic floor exercises, biofeedback, and timed bladder emptying
What things can cause urinary urgency?
- Stroke
- Alzheimer or Parkinson
- BPH with overflow
What is the treatment for urinary urgency/incontinence?
- anticholingerics
- oxybutynin
- tolterodine
What things can cause urinary outlet incompetence (urinary loss with cough, sneeze, laugh, etc.)?
- multigravida
- estrogen deficiency
What is the treatment for urinary outlet incompetence?
focus on muscle exercise by focusing when these things happen
- Topical estrogen
- And then give Alpha-agonists last because of potential side effects
What things cause atonic bladder?
- severe diabetic neuropathy
- stroke
What is the treatment for atonic bladder?
catheterization
What are some oral non-selective muscarinic antagonist drugs?
- Darifenacin PO
- Transdermal Oxybutynin
How are the non-selective muscarinic antagonist drugs metabolized?
Extensive hepatic metabolism involving CYP3A4/2D6 (except tropsium)
What does parasympathetic activity in the bladder cause?
Parasympathetic postganglionic axons in the pelvic nerve release acetylcholine (ACh), which produces a bladder contraction by stimulating M3 muscarinic receptors in the bladder smooth muscle.
Parasympathetic postganglionic nerves also release ATP, which excites bladder smooth muscle, and nitric oxide, which relaxes urethral smooth muscle
What does sympathetic activity in the bladder cause during filling?
Sympathetic postganglionic neurons from the hypogastric nerve release noradrenaline (NA), which activates β3 adrenergic receptors to relax bladder smooth muscle/detrusor and also activates α1 adrenergic receptors in the urethra to contract urethral smooth muscle.
What do somatic axons in the pudendal nerve do?
Also release Ach, which produces a contraction of the external sphincter striated muscle by activating nicotinic cholinergic receptors.
What is a benefit over a muscarinic antagonist like trospium for urinary incontinence?
it doesnt pass the BBB so less side effects
dry mouth common
T or F. Although M3 receptor specificity is more selective for darifenacin (muscarinic antagonist), clinical studies have not recorded a substantially better profile for this drug in clinical use, as compared to the other, non-selective, drugs like oxybutynin and tolterodine
T.
The half lives of muscarinic antagonists vary from short to long.
The reason for oxybutynin and tolterodine being available in extended release (ER) formats is to counter their otherwise short duration of clinical effect.
T or F. ER delivery reduces risk of dry mouth without any apparent loss of efficacy
T.
What are some AEs with muscarinic antagonists?
- palpitations, tachycardia, prolonged QT
- mild constipation
What are some contraindications to muscarinic antagonists?
- angle closure or narrow-angle glaucoma
- urinary and gastric obstruction
- Alzheimer’s
What else can be used in urinary incontinence?
botulinum toxin (botox)- Delivered by carefully placed injections into the urothelial wall
How long does botox help with urinary incontinence after injection?
several months
Note about botox use
The botox is more effective in patients who responded to anticholinergic drugs but couldn’t tolerate the adverse effects, as opposed to those patients who were unresponsive to the anticholinergics.
How does the botulinum toxin work?
It inhibits vesicular release of excitatory neurotransmitters and axonal expression of other SNARE-complex-dependent proteins in the urothelium /suburothelium mediating intrinsic or spinal reflexes thought to cause detrusor overactivity
What else does the botulinum toxin do?
It also causes a phenotypic change within the urothelial tissue to ablate the excitatory effect of local chemical mediators that signal via the cholinergic system to make the bladder hyper-responsive in the first instance.
What is mirabegron?
daily PO drug that promote sympathetic activity in the bladder (B3) and the urethra (a1)
How is mirabegron metabolized?
extensive hepatic metabolism (3A4 over 2D6)
What are some other sympathetic stimulating drugs in the bladder?
- Pseudoephredine
- Ephedra (ma-huang)
both used ‘off-label’
How are Pseudoephredine and Ephedra (ma-huang) metabolized?
eliminated predominantly unchanged in urine (dose reduction may be needed with renal dysfunction)
As of sympathetic stimulators in the bladder/urethra?
- HTN
- tachycardia
- anxiety, restlessness, nervousness, insomnia