Overactive bladder
Overactive bladder is a urological condition defined by a set of symptoms: urgency, with or without urge incontinence, usually with frequency and nocturia
Nocturia , also called nycturia , is the need to get up in the night to urinate, thus interrupting sleep. Its occurrence is more frequent in pregnant women and in the elderly...

. Frequency is usually defined as urinating more than 8 times a day. The International Continence Society
International Continence Society
The International Continence Society is an international society of medical professionals, with national chapters, interested in the study of the lower urinary tract...

 is responsible for this definition. There exists, however, some controversy over the use of this term because these symptoms taken in isolation may overlap with those of other bladder conditions, including interstitial cystitis
Interstitial cystitis
Interstitial cystitis or bladder pain syndrome is a chronic, oftentimes severely debilitating disease of the urinary bladder...

, or rarely even bladder tumours.


The etiology
Etiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....

 of OAB is unclear, and indeed there may be multiple possible causes. It is often associated with overactivity of the Detrusor urinae muscle
Detrusor urinae muscle
The detrusor urinae muscle, also detrusor muscle, muscularis propria of the urinary bladder and muscularis propria, contracts when urinating to squeeze out urine. Otherwise, it remains relaxed to allow the bladder to fill...

, a pattern of bladder muscle contraction observed during urodynamics
Urodynamic testing
Urodynamic testing refers to the process of performing urodynamics. Urodynamics is a study that assesses how the bladder and urethra are performing their job of storing and releasing urine...

. Treatments for OAB are usually synonymous with treatments for detrusor overactivity. OAB is distinct from stress urinary incontinence, but when they occur together, the condition is usually known as mixed incontinence.

Earlier reports estimated that about one in six adults in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 and Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 had OAB. The prevalence of OAB increases with age, thus it is expected that OAB will become more common in the future as the average age of people living in the developed world is increasing. However, a recent Finnish population-based survey suggested that the prevalence had been largely overestimated due to methodological shortcomings regarding age distribution and low participation (in earlier reports). It is suspected, then, that OAB affects approximately half the number of individuals as earlier reported.

In 2008 researchers found that simulating the condition in rats caused overactivation of their locus coeruleus, and it is thought this could cause anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...

 and disrupted sleep in humans.


Treatment for OAB includes lifestyle modification (fluid restriction, avoidance of caffeine
Caffeine is a bitter, white crystalline xanthine alkaloid that acts as a stimulant drug. Caffeine is found in varying quantities in the seeds, leaves, and fruit of some plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants...

), bladder retraining, antimuscarinic drugs (e.g. darifenacin
Darifenacin is a medication used to treat urinary incontinence. It used to be marketed by Novartis; however in 2010 US rights for were sold to Warner Chilcott for 400 million US$....

, hyoscyamine
Hyoscyamine is a tropane alkaloid. It is a secondary metabolite found in certain plants of the Solanaceae family, including henbane , mandrake , jimsonweed , tomato and deadly nightshade...

, oxybutynin
Oxybutynin is an anticholinergic medication used to relieve urinary and bladder difficulties, including frequent urination and inability to control urination , by decreasing muscle spasms of the bladder. It competitively antagonizes the M1, M2, and M3 subtypes of the muscarinic acetylcholine...

, tolterodine
Tolterodine is an antimuscarinic drug that is used to treat urinary incontinence.It is marketed by Pfizer in Canada and the United States by its brand name Detrol. In Egypt it is also found under the trade names Tolterodine by Sabaa and Incont L.A...

, solifenacin
Solifenacin is a urinary antispasmodic of the antimuscarinic class. It is used in the treatment of overactive bladder with or without urge incontinence. It is manufactured by Astellas and co-marketed by Astellas and GlaxoSmithKline.- Mechanism of action :Solifenacin is a competitive muscarinic...

, trospium
Trospium chloride is a muscarinic antagonist urinary antispasmodic. It has been developed and patented by Robert Pfleger and is sold under the brand name Sanctura in the US, Tropez OD in India,Trosec in Canada, Regurin and Flotros in the United Kingdom and Spasmex in Germany, Russia, Turkey,...

), and various devices (Urgent PC Neuromodulation System, InterStim). Botulinum toxin A (Botox) is approved by the FDA in adults with neurological conditions, including multiple sclerosis
Multiple sclerosis
Multiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...

 and spinal cord injury
Spinal cord injury
A spinal cord injury refers to any injury to the spinal cord that is caused by trauma instead of disease. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence...

. Botulinum Toxin A injections into the bladder wall can suppress involuntary bladder contractions by blocking nerve signals and may be effective for up to 9 months. The antimuscarinic fesoterodine
Fesoterodine is an antimuscarinic drug developed by Schwarz Pharma AG to treat overactive bladder syndrome . It was approved by the European Medicines Agency in April 2007 and was approved by the US Food and Drug Administration on October 31, 2008.Fesoterodine is a prodrug...

 was recommended for approval by the European Medicines Agency
European Medicines Agency
The European Medicines Agency is a European agency for the evaluation of medicinal products. From 1995 to 2004, the European Medicines Agency was known as European Agency for the Evaluation of Medicinal Products.Roughly parallel to the U.S...

in February 2007. A surgical intervention involves the enlargement of the bladder using bowel tissues, although generally used as a last resort. This procedure can greatly enlarge urine volume in the bladder.

Support Resources

Information Resources

  • Overcoming Overactive Bladder
  • Interstitial Cystitis Survival Guide
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