Pharmacotherapy of Urinary Incontinence in the Elderly Flashcards
Causes of urge incontinence
- infection
- neurologic disorder
- diabetes
- acetylcholinesterase inhibitors
- diuretics
- lithium
- caffeine
- alcohol
Causes of functional incontinence
neurological injury
Causes of urinary retention
- Alpha 1 receptor agonist especially in men (i.e. phenylephrine, phenylpropanolamine, clonidine, guanfacine)
- Drugs with anticholinergic side effects (i.e. antihistamines, antiparkinsonian agents, antidepressants, antipsychotics)
- Beta-agonist, narcotics
Causes of urethral underactivity
- Alpha 1 receptor antagonists (in women – carvedolol, labetolol , mirtazepine, tarazosin, doxazosin)
- ACE inhibitors which induce cough
T/F; For both urge incontinence and stress incontinence, bladder training and pelvic floor muscle training are important components of therapy
True
General Principles to Guide Pharmacotherapy of Urge Incontinence (UI)
- start medications on lowest possible dose to minimize common side effects
- allow sufficient time to adequately assess efficacy
- concomitant behavioral therapy may enhance drug response
What are the anticholinergics used in UI?
- Oxybutynin
- Tolterodine
- Trospium chloride
- Solifenacin succinate (VESIcare*)
- Darifenacin hydrobromide (Enablex*)
- Fesoterodine (Toviaz*)
Oxybutynin
- Immediate Release (Ditropan* and generics) – Geriatric Patients: 2.5 to 5 mg up to three times daily. Change dose no more frequently than once per month
- Extended Release (Ditropan XL* and generics) – 5 mg once per day. Change doses no more frequently than once per month
- Transdermal patch– twice weekly (Alleged decreased anticholinergic effects)
- Gel (Gelnique*) – daily application (Alleged decreased anticholinergic effects)
Tolterodine
- Immediate Release (Detrol* and generics) – Geriatric Patients: 1 to 2 mg twice daily. Change dose no more frequently that once per month
- Extended Release (Detrol LA* and generics) – Geriatric Patients: 2 to 4 mg daily. Change dose no more frequently than once per month
Trospium chloride
- 20 mg BID
- Dose should probably be 20 mg q d in patient over 75 years of age as renal function may be decreased
- ER -> 60 mg
Solifenacin succinate (VESIcare*)
- 5mg once per day
- Drug interaction with potent 3A4 inhibitors (clarithromycin, ketoconazole, ritinovir)
Darifenacin hydrobromide (Enablex*)
- 7.5 to 15 mg once per day
- Drug interactions with potent 3A4 inhibitors
MOA of anticholinergics
Muscarinic receptor antagonists acting on the smooth muscle of the bladder to decrease bladder contractility and increase bladder capacity
Toxicity of Anticholinergics in Urge Incontinence
- Drop out rate for oxybutynin IR = 20% due most often to severe dry mouth (xerostomia) leading to taste disturbance, anorexia, difficulty chewing, esophogeal dysmotility, etc.
- Drop out rates for oxybutynin XL and the tolterodine compounds are less than 10% with dry mouth remaining the most common complaint
- Other side effects expected from anticholinergics include dry eyes, blurred vision, constipation, reflux, confusion and SVT
- Oxybutynin likely has the greatest amount anticholinergic effects
- Tolterodine probably produces troublesome CNS effects less frequently than does oxybutynin due to the fact that it is less likely to cross the blood-brain barrier
Drug interactions with the UI medicationsn
- potent CYP 3A4 inhibitors such as macrolide antibiotics (clarithromycin), imidazole antifungal agents, ritinovir –> decrease dose of tolterodine, solifenacin, darifenacin and fesoterodine by 50%
- antacids and PPIs interact with tolterodine LA