Cheryl Ritchie R.Ph.,
CGP
Janzen’s Pharmacy
Thunder Bay, ON

Medications and Urinary incontinence
Presentation Outline
 Bladder receptors – Drug activity sites
 Drugs contributing to urinary incontinence
 Drugs for treatment of urinary incontinence

Alpha Adrenergic Receptors in Bladder
–
–
Stimulation
 Sphincter contraction
– Inhibit urine flow
Block receptors
 Sphincter relaxation
– Allow urine flow

Beta adrenergic receptors in bladder


Stimulation
– Detrusor muscle relaxation
 Allows bladder filling
Block receptors
– Detrusor muscle contraction
 Facilitates bladder emptying

Muscarinic (M2 & M3 - Cholinergic)
Receptors


Stimulation
– Detrusor muscle contraction
 Facilitates bladder emptying
Block receptors
– Detrusor muscle relaxation
 Facilitates bladder filling

Medications contributing to
Incontinence
 Stress Incontinence
–
–
Alpha adrenergic blocking agents cause sphincter relaxation
 Terazosin
 doxazosin
ACE inhibitors may cause cough
 Enalapril
 Ramipril
 Lisinopril
 fosinopril

Medications contributing to Urinary
Incontinence
 Urge incontinence due to uncontrolled bladder contractions or increased urine output
–
–
Diuretics
Caffeine
– Sedative Hypnotics

Medications contributing to urinary incontinence
 Urinary retention due to decreased bladder contractions
–
–
–
–
–
–
–
Anticholinergics – oxybutynin, scopolamine
Antidepressants – amitriptyline, doxepin
Antipsychotics – chlorpromazine, prochlorperazine
Sedative hypnotics – diazepam, flurazepam
Antihistamines – diphenhydramine, hydroxyzine, chlorpheniramine
Muscle relaxants – baclofen, cyclobenzaprine
Calcium Channel Blockers – diltiazem,nifedipine, verapamil
–
–
Antiarrhytmics - quinidine
Antiparkisonian agents – trihexyphenidyl, benztropine

Medications Contributing to Urinary
Incontinence
 Urinary retention due to sphincter contraction
– Alpha adrenergic agonists
 pseudoephedrine
 Urinary retention due to detrusor muscle relaxation
– Beta adrenergic agonists
 Salbutamol
 terbutaline

Medications contributing to urinary incontinence
 If medications are a contributing factor – consider an alternative medication
 If not able to discontinue offending medication, the lowest possible dose of the aggravating medication should be used.

Medications to treat urinary incontinence - goals of treatment
 Decrease uninhibited bladder contractions
 Increase functional bladder capacity
 Decrease frequency and urgency

Drugs in the management of urinary incontinence – Points to consider
 Will adding medication improve or complicate quality of life?
 Drug therapy alone rarely cures elderly urinary incontinence sufferers.
 Ensure accurate diagnosis prior to choosing drug therapy

Drugs in treatment of urinary incontinence – stress incontinence
 Topical estrogens

– Increase sphincter tone
Duloxetine – unlabelled use
– By blocking norepinehrine reuptake may increase sphincter control

Drugs in the treatment of urinary incontinence – Urge incontinence
 Oxybutynin - Ditropan
 Tolterodine - Detrol

Drugs in the treatment of urinary incontinence – Urge incontinence
 Adverse effects of oxybutynin & tolterodine
– Dry mouth
–
–
Constipation
Dry eyes or blurred vision
– Tachycardia
– Worsening GERD
– Worsening cognitive impairment (especially with cholinesterase inhibitors)

Drugs in the treatment of urinary incontinence – Urge incontinence
 Contraindications
– Urinary and gastric retention
– Uncontrolled narrow angle glaucoma

Drugs in the treatment of urinary incontinence – Urge incontinence
 Drug interactions
– Additive effects with other anticholinergic medications
– Tolterodine only (reduce dose)
 Azole antifungals
 Cyclosporine
 Macrolide antibiotics
 Fluoxetine – if possible choose alternative SSRI

Drugs in the treatment of urinary incontinence – Urge incontinence
 Dosage form availability
– Immediate release tablet
–
–
Extended release tablet
Transdermal patch (oxybutynin only)
 Dosage form notes
– Short acting may be good choice for occasional use for special occasions
– Long-acting formulation may cause less adverse effects

Drugs in the treatment of urinary incontinence – overflow incontinence
 UI associated with benign prostatic hyperplasia
– Alpha adrenergic antagonists
 Terazosin, doxazosin
– Non-selective – monitor for hypotension especially with first dose
 alfuzocin, tamsulosin
– 5-alpha reductase inhibitors
 Finasteride, dulasteride

Drugs in the management of urinary incontinence – Points to consider
 Several weeks of drug therapy are usually required to achieve maximum effect
 If no subjective improvement in 4-6 weeks, consider
– Increase dose
– Change medication
– Discontinue medication