Pilot study of sequential oral antibiotics for the treatment of interstitial cystitis

Purpose: Interstitial cystitis is a chronic disease of unknown etiology cha racterized by bladder pain, urgency and frequency. Although a single microb e has not been implicated as a cause of interstitial cystitis, several grou ps noted various organisms in the urine of some women with interstitial. cy stitis and some patients reported that antibiotics decrease symptoms. Conse quently we performed a prospective, randomized, double-blinded, placebo con trolled pilot study of sequential oral antibiotics. Materials and Methods: We randomized 50 patients with interstitial cystitis to receive 18 weeks of placebo or antibiotics, including rifampin plus a s equence of doxycycline, erythromycin, metronidazole, clindamycin, amoxicill in and ciprofloxacin for 3 weeks each. Results: Intent to treat analysis demonstrated that 12 of 25 patients (48%) in the antibiotic and 6 of 25 (24%) in the placebo group reported overall improvement (p = 0.14), while 10 and 5, respectively, noticed improvement i n pain and urgency (p = 0.22). In the antibiotic group 20 participants (80% ) had adverse effects compared with 10 (40%) in the placebo group (p = 0.00 9). Conclusions: Our findings suggest that these antibiotics alone or in combin ation may sometimes be associated with decreased symptoms in some patients but they do not represent a major advance in therapy for interstitial cysti tis.