The generalist’s guide to interstitial cystitis

Normal bladder capacity under anesthesia is 1,000 cc, but it is reduced in women with interstitial cystitis. Bladder capacity of 450 cc or less under anesthesia indicates a more contracted bladder and a later-stage disease. Glomerulations, petechiae, fissures, or (rarely) Hunner’s ulcers typically are visible, regardless of bladder volume. However, the presence of glomerulations does not necessarily make the diagnosis, because they can be found in asymptomatic women. Further, cystoscopic observations do not always correlate with the severity of symptoms (nor does positive biopsy always reflect interstitial cystitis).

Hydrodistention is not only diagnostic, but also can be therapeutic, as sympathetic nerve fiber density decreases afterward.¹¹ However, the need for this procedure is under debate, due to the limitations described above. A bladder capacity less than 1,000 cc with the presence of glomerulations or petechiae and fissures, with or without the Hunner’s ulcers, constitutes a definitive diagnosis.

Cystoscopy under anesthesia is recommended because medical treatment can be costly and cause significant side effects. An accurate diagnosis should precede therapy to avoid misdirected therapy in a patient who does not have interstitial cystitis. Moreover, cystoscopy can rule out bladder neoplasms or other diseases. Some bladder carcinomas have been missed in women treated empirically for interstitial cystitis.¹²

Cystoscopic images “paint a thousand words.” When a woman sees her cystoscopy images, the picture indeed “paints a thousand words.” For many women, the images “justify” their symptoms and confirm that the disease is real.

CASE Don’t treat a UTI without a positive culture

“M.P.” is a healthy 44-year-old G2P2 with a history of recurrent UTIs. Approximately 14 months ago, while on vacation, she began having symptoms of urinary frequency, urgency, and lower abdominal pain that were relieved with voiding. She called her primary care physician, who prescribed levofloxacin and phenazopyridine over the phone for a presumed UTI. Since the patient was out of town, a urine culture was not obtained.

When M.P. returned from vacation, her symptoms recurred, so she underwent urinalysis, including culture and sensitivity, and began a 7-day course of nitrofurantoin (100 mg twice daily). When her symptoms did not improve by day 4, a second course of levofloxacin was given. The urine culture was sterile. As her physician recommended, M.P. increased her fluid intake, including water and cranberry juice. She also avoided sexual relations, since they exacerbated her symptoms, which improved overall but did not clearly abate.

Three months later her symptoms returned in full force.

How would you treat this patient?

Interstitial cystitis can produce symptoms consistent with a lower UTI, but urine cultures will be negative and the response to antibiotics will be minimal. Many patients call their physicians and report “another UTI.” However, if the woman is healthy with no history of renal disease or diabetes, consider interstitial cystitis. Obtain urine culture results from other physicians, if possible, to determine whether bacterial infection was ever confirmed.

Cranberry juice is acidic and may exacerbate urgency and pain.

What to tell patients

The Interstitial Cystitis Association (ICA) encourages patients to become involved in their own care. The ICA was formed in 1984 by women with painful bladder symptoms who had been told by their physicians that nothing was wrong. The organization provides patients with clinical research updates, clinical trial opportunities, and literature and information.

Once the diagnosis is confirmed, patient education and counseling are imperative. Compliance is critical.

There is no cure for interstitial cystitis; the disease is chronic, with relapses and remissions. Although it does not progress once it develops fully, improvement is slow, usually occurring after 3 months or more of treatment. No single treatment works for all patients, so empiric trials with various agents may be needed. Treatment often is multimodal, and the rationale for each therapy should be explained.

Have the patient keep a voiding diary before and after treatment, as well as during any flare-up, to provide evidence of improvement and identify triggers. Also instruct her to pay attention to any foods or activities that exacerbate her symptoms (eg, caffeine, sexual activity).

Treatment

Does a change in diet help?

Some foods and beverages apparently exacerbate symptoms, although the link between foods and symptoms has not been fully investigated. About 53% of patients with interstitial cystitis associate symptom aggravation with dietary factors, especially acidic foods and beverages.⁵ Dietary restrictions should be attempted for 1 to 2 weeks to determine which foods to avoid.

Gillespie¹³ found elevated urine levels of tryptophan metabolites in women with hypersensitive bladders, compared with controls.

Tryptophan metabolites may disrupt the glycosaminoglycan layer of the bladder epithelium, as seen in a study involving rabbit bladders.¹⁴