Drugs acting on the bladder

Anti-cholinergic agents

• Include Oxybutynin, Tolterodine, Propiverine, Solifenacin
• Result in improvement in 57-71% of women with detrusor overactivity
• There is s significant placebo effect.
• Side-effects,especially dry mouth appear to be less common with newer agents like Solifenacin.

Oxybutynin - Side-effects include:

• Nausea, constipation, diarrhoea and abdominal discomfort
• Dry mouth (88%)
• Blurred vision
• Voiding difficulties
• Headache, dizziness, drowsiness, restlessness and disorientation
• Rash, dry skin, photosensitivity
• Arrhythmia
• Angioedema

Tolterodine has similar efficacy to oxybutynin but is be better tolerated
Propiverine is also a calcium channel blocker

Solifenacin is a newer agent with organ selectivity for the bladder over the salivary gland. Similar efficacy to other agents with respect to bladder function.

Tricyclic antidepressants

• Have anti-cholinergic effects and also sedative - useful in nocturia and nocturnal enuresis. Main side-effects are drowsiness and postural hypotension

Anti-diuretic hormone DDAVP

• Effective in treatment of nocturia and nocturnal enuresis. Contraindicated in cardiac disease and women on diuretics. Side-effects include fluid retention with hyponatraemia, epistaxis, nasal congestion and rhinitis with nasal spray

Oestrogen

• Effective in relieving symptoms of uro-genital atrophy in post-menopausal women (frequency, urgency and dysuria), no evidence that it is effective in proven detrusor overactivity

Duloxetine

• Combined serotonin and noradrenaline re-uptake inhibitor
• Increased synaptic concentrations of noradrenaline and 5HT within the pudendal nerve results in increased stimulation of the urethral sphincter
• Increases sphincter activity in the storage phase of the micturiction cycle

Clinical use

• Treatment of stress incontinence - useful in women awaiting surgery or women who have not completed their family - contraindicated in pregnancy
• May be used in women who wish to avoid surgical intervention - physiotherapy remains a useful first line option
• Cannot be considered as an alternative to surgery as long-term data not available

Side-effects

• GI disturbance particularly nausea and dry mouth
• Headache, decreased libido, anorgasmia
• Withdrawal reaction is characterised by headache, nausea, paraesthesia, dizziness and anxiety - drug should not be stopped abruptly and dose should be reduced over a 2 week period

Contraindications

• Pregnancy, lactation
• Hepatic impairment
• Monoamine oxidase therapy
• Lowers seizure threshold therefore avoid in epilepsy
• Can enhance the anti-coagulant effects of warfarin
• Metabolised by the same enzymes as ciprofloxacin and fluvoxamine - avoid co-prescription
•  Avoid co-prescription with SSRIs and tricyclic anti-depressants