INTERSTITIAL CYSTITIS

     Interstitial cystitis (IC) is a condition which manifests as bladder/suprapubic/pelvic pain, urgency, frequency, nocturia and dysuria.  The cause of IC is unknown.  Female patients are affected much more frequently than male patients, and the majority of patients are Caucasian.  The chronicity and severity of pain often interferes with the patient’s quality of life.  These patients have often been treated repeatedly for cystitis despite negative cultures and a poor response to antibiotic therapy.  The diagnosis is established via cystoscopy and hydrodistention, which reveals petechial hemorrhages, linear cracks and/or ulcerations (Hunner’s ulcers) of the bladder mucosa; however, this requires a urology referral and an invasive procedure.  Primary care physicians may spare the time required for a consult by performing the potassium sensitivity test.  The patients bladder is catheterized and then first distended with 40 cc of water.  The level of discomfort is recordered, and then the bladder is drained and filled with 40 cc of a potassium solution.  At this point, the level of discomfort is again recorded.  Patients suffering from interstitial cystitis will report a significant increase in discomfort with the infusion of the potassium solution.  Prior to initiating an evaluation it is prudent to exclude bacterial cystitis or prostatitis, and in appropriate cases, bladder malignancies as possible etiologies.  Other conditions to consider include chemical cystitis, radiation cystitis, tuberculous cystitis and endometriosis.  When the diagnosis seems certain, an empiric trial of therapy may be prudent.

     Urinalysis may reveal hematuria or pyuria.  Urine cultures will be sterile.  Urine cytology is useful to eliminate bladder cancer as the cause of symptoms in appropriate patient populations.  Vaginal wet mounts with NaCl and 10% KOH are useful to eliminate infection with trichomonas, yeast and bacterial vaginosis.  Cystometry can be used to evaluate patients.  When patients fail to experience an urgency to void on filling of the bladder, the diagnosis may be excluded.  Cystoscopy with bladder hydrodistention is the most effective means of establishing the diagnosis and may prove therapeutic.

     Therapy includes avoidance of caffeine containing beverages, alcohol, and foods that may decrease the urine pH (citrus fruits, tomatoes, etc).  Symptoms may respond to hydroxyzine (25-100 mg QHS), amitripyline (25-75mg QHS) plus an NSAID, or pentosan polysulfate (200 mg BID for females and 200 mg TID for males-the doses are eventually lowered as tolerated to 100 mg QAM and 200 mg QPM for females and 200 mg BID for males).  Often times hydrodistention itself may prove therapeutic in some patients.  Intravesical therapies include dimethyl sulfoxide weekly for 6 weeks, sodium oxychlorosene, silver nitrate, heparin, capsaicin, lidocaine, and bacille Calmette-Guerin (BCG) vaccine.  Combination therapy (i.e. intravesical pentosan polysulfate and heparin) is often more successful than single agent regimens.  Since it often takes a period of trial (be sure to allow each therapy adequate time to have an effect) and error to determine which therapy is effective for an individual patient, physicians should have a honest and lengthy discussion at the outset of initiating therapy so patients do not become discouraged.  If no therapy proves completely effective, experimentation with different combinations of agents should be employed.  Refractory cases may get some relief after consultation with a pain clinic specialist.  Narcotics should be considered in persistent cases of pain after all other options have been exhausted.