Overactive bladder syndrome (OAB) is the presence of urinary urgency (with or without urge incontinence) and usually with increased urinary frequency and nocturia.
It is a common condition with an overall prevalence of 16-20 per cent in patients aged over 40. In the over-75s this rises to 30-40 per cent.
OAB has a major impact on the quality of life of those affected. Discomfort aside, sufferers find they have to plan their days around the need to be close to a toilet.
Sleep disturbance can also increase the rates of falls and fractures in the elderly.
The first challenge for GPs is in the identification of patients with OAB. Only 15 per cent of sufferers seek treatment, so there is a role for case finding during opportunities such as 75 plus health checks, well women clinics and when carrying out cervical smears.
Typical symptoms of OAB are urinary urgency, urinary frequency (micturations of more than eight times a day, nocturia (urinary frequency of more than twice per night) and urge incontinence (involuntary loss of urine following a strong urge).
These can occur alone but are often combined with symptoms of stress urinary incontinence. The GP should also enquire about red flags such as pain and haematuria that might indicate alternative diagnoses. (see box below)
The examination should include abdominal palpation for masses and bladder distension. In men, a prostate examination should be carried out.
In women, a pelvic examination should look for pelvic masses, uterine prolapse, vaginal wall herniation, pelvic floor function and stress incontinence (cough test).
OAB is predominantly a clinical diagnosis, but some investigations can aid diagnosis and management.
All patients should have a urinalysis/MSU for infection and/or haematuria. A frequency/volume diary over a week can evaluate the degree of severity and detect compulsive fluid drinkers or excessive alcohol or caffeine intake. Blood tests might be warranted if the history suggests syst-emic disease.
Other tests might require referral to secondary care. Ultrasound investigations can measure residual urine and detect urinary tract and pelvic abnormalities.
Flow rate analysis in men can detect outflow obstruction. Urodynamics can distinguish the causes of OAB, but is best reserved for complex cases or where there is diagnostic doubt.
Most OAB treatments can be initiated in primary care.
Co-morbid conditions, such as UTI, constipation and diabetes should be treated first. In addition, diuretic use should be reviewed. Conservative treatment can be organised via the local continence adviser (see box).
Drug therapy can be used in conjunction with conservative therapy or if initial management fails.
A number of drugs have been used for the detrusor over-activity that causes much of OAB. However, many of them are not without problems including side-effects, in particular anticholinergic symptoms such as dry mouth and dyspepsia.
These drugs can also interact with other medications and cause cognitive changes or confusion. These effects can be problematic in the frail elderly where either lower doses or avoidance of drugs might be required.
Drug therapy is affected by poor compliance, often due to anticholinergic effects. One study showed that only 18 per cent of patients continue treatment beyond 18 months.
Oxybutynin has been the most commonly prescribed treatment, but is limited by high levels of side-effects.
The commonest complaint is dry mouth, affecting 87 per cent of users (moderate or severe in 46 per cent).
Slow-release or transdermal preparations might reduce the level of side-effects, but these remain relatively high.
More recent drugs can offer benefits over oxybutynin and lead to better compliance.
Propiverine is as effective, but better tolerated than oxybutynin. It causes around half the incidence of severe dry mouth. Anticholinergic effects diminish with time (in oxybutynin they increase).
Tolterodine does not readily cross the blood brain barrier; however 28 per cent of patients still report dry mouth. Slow-release preparations might be better tolerated.
Trospium has equivalent efficacy to oxybutynin. It does not cause CNS effects.
Solifenacin is a new long acting preparation which appears to be effective in reducing the symptoms of OAB.
Propantheline is effective for frequency but less so for other symptoms. It has low bioavailability and needs higher doses to be effective. Drugs such as tricyclics, alpha-blockers, beta-agonists and NSAIDs have limited evidence to support their use.
Referral to an urologist or urogynaecologist may be needed if there is diagnostic doubt.
Specialist investigations, such as urodynamics or cystometry can give a definitive answer and aid treatment planning. Referral is also appropriate should initial treatments fail or are not tolerated. Finally there are patients with severe refractive OAB where a surgical option might be considered.
Operations include cystoplasty operations that increase the bladder capacity; sacral neuromodulation (implantation of a pulse-generator to stimulate the S3 nerve root) and botulinum toxin injected into the detrusor.
OAB presents GPs with both a diagnostic and management challenge.
However, with careful choice of treatment and patient counselling, GPs can successfully manage most patients with the condition.
- Dr Spinks is a GP with an interest in urinary continence in Strood, Kent
CONSERVATIVE TREATMENT FOR OAB
- Lifestyle interventions, advice on weight loss, smoking and alcohol or caffeine intake.
- Pelvic floor exercises are needed if stress incon-tinence is also present. Vaginal cones may be used.
- Bladder retraining involves slowly prolonging the interval between urination by setting targets to delay urination after the first urge.
- Timed voiding is deciding urination times to reduce the impact of frequency.
- Detrusor over-activity.
- Prostatic hypertrophy/carcinoma.
- Oestrogen deficiency.
- Interstitial cystitis.
- Bladder calculus.
- Bladder tumour.
- Pelvic mass.
- Milsom I, Abrams P, Cardozo L et al. How widespread are the symptoms of an overactive bladder and how are they managed? A population-based prevalence study. BJU Int 2001; 87: 760-6
- Van der Vaart C H, De Leeuw J R, Roovers J P, Heinz A P. The effect of urinary incontinence and overactive bladder symptoms on quality of life in young women. BJU Int 2002; 90: 544-9
- Dugan E, Roberts C P, Cohen S J et al. Why older community-dwelling adults do not discuss urinary incontinence with their primary care physicians. J Am Geriatric Society 2001; 49: 462-5
- Kelleher C J, Cardozo L, Khullar V et al. A medium-term analysis of the subjective efficacy of treatment for women with detrusor instability and low bladder compliance. Br J Obstet Gynaecol 1997; 104: 988-93
- Appell R A, Abrams P, Drutz H P et al. Treatment of overactive bladder: long-term tolerability and efficacy of Tolterodine. World J Urol 2001; 19: 141-7
- Hofner K, Halaska M Primus G et al. Tolerability and efficacy of Trospium chloride in long-term treatment (52 weeks) in women with urge-syndrome: a double blind, controlled, multicentre clinical trial. Neurourol Urodyn 2000; 19: 487
- Cardozo L, Lisec M, Millard R et al. Randomized, double-blind placebo controlled trial of the once daily antimuscarinic agent solifenacin succinate in patients with overactive bladder. J Urol 2004; 172: 1919-24.