Mild sedatives are sometimes helpful in this process, as are α-blockers (e.g., prazosin, phenoxybenzamine, tamsulosin), which reduce urethral tone. Although cholinergic medications such as bethanechol chloride are successful in making strips of bladder muscle contract in a laboratory, there is little evidence that such drugs are helpful clinically (148).
Most patients with disorders of bladder sensation experience pain rather than lack of bladder sensation. As with the treatment of most chronic pain disorders, the cause of most painful bladder conditions is unknown, and the therapies used are only partially successful. As a result, disorders of bladder sensation are among the most frustrating urogynecologic conditions to manage.
Bladder pain syndrome, often termed interstitial cystitis, is a poorly defined heterogeneous syndrome, and diagnostic criteria are changing continuously. The International Continence Society standardization report recommends adapting the term bladder pain syndrome, rather than interstitial cystitis, and defines painful bladder syndrome as “an unpleasant sensation (pain, pressure, discomfort) perceived to be related to the urinary bladder associated with lower urinary tract symptom(s) of more than 6 weeks duration, in the absence of infection or other identifiable causes” (15). Urgency and pain are the defining characteristics of bladder pain syndrome (149). Several factors have inhibited advances in the understanding of interstitial cystitis, including the lack of specific diagnostic criteria, the lack of specific histopathologic changes, the unpredictable ﬂuctuation in symptoms, and the marked variability among patients in terms of symptoms, objective findings, and treatment responses (150).
The National Institute of Diabetes, Digestive, and Kidney Diseases (NIDDK) developed a research definition for interstitial cystitis that requires objective findings of glomerulations or a classic Hunner’s ulcer during hydrodistention of the bladder and subjective symptoms of bladder pain or urinary urgency in the absence of other urogenital pathology (151). Strict application of NIDDK criteria in one study would have misdiagnosed more than 60% of patients thought to definitely or possibly have interstitial cystitis (152). Many clinicians have challenged the clinical utility of the NIDDK research criteria, and most conceptualize interstitial cystitis as the end point on the spectrum of painful bladder disorders (153).
The prevalence of bladder pain syndrome varies widely depending on the diagnostic criteria utilized. When mild and moderately severe cases are considered, the syndrome is not rare (154). Estimates of prevalence in the United States range from 52 per 100,000 women in the population-based Nurses Health Study to as high as 1 in 4.5 women “with accurate diagnostic records” (155,156). The prevalence appears to be 6 to 15 times more common among women than men (155,157). The identification of risk factors for bladder pain syndrome is particularly challenging because of the typically long delay in diagnosis (154). The Interstitial Cystitis Database study confirms many of the previous epidemiologic observations: affected individuals are predominately female (92%), white (91%), and report an average age of symptom onset of 32.2 years (150,155).