Clinical features of tiaprofenic acid (surgam) associated cystitis and a study of risk factors for its development

A case-control study was performed to describe the clinical course and iden tify risk factors predisposing to the development of tiaprofenic acid assoc iated cystitis. Cases were identified from reports to the Australian Advers e Drug Reactions Advisory Committee and a two-year (1995-1996) national sur veillance programme. Definition of a case was onset of symptoms of cystitis while taking tiaprofenic acid with pyuria (>10 WBC/mu l) and/or hematuria (>10 RBC/mu l), and no evidence of urinary tract infection. Definitions of "prescriber-matched" and "unmatched" controls were those who had been presc ribed tiaprofenic acid by the same prescriber within 12 months of the case without developing cystitis or were identified from the databases of local pharmacies of the cases respectively. 81 of 109 identified cases and 109 of 184 potential controls completed a standardised interviewer-administered q uestionnaire. Median time between the commencement of tiaprofenic acid and symptom onset was 6.3 months (range 0.1-47.1 months). Median interval betwe en presentation to doctor and drug cessation was 3.0 months (range 0-24.5 m onths). In half the patients, symptoms resolved within 14 days of ceasing t herapy. Increasing age was a risk factor for the development of tiaprofenic -acid associated cystitis, age >70 years-odds ratio 3.2 (95% confidence int erval 1.3-7.9) compared with age <55 years. Patients taking aspirin had a r educed risk (odds ratio 0.3, 95% confidence interval 0.1-0.9). Dose and amo unt of fluid consumed per day were not related to the risk of cystitis. Ear lier recognition of tiaprofenic acid associated cystitis can potentially re duce the morbidity related to this condition. Apart from an increased risk among older patients, it is likely that this condition represents a drug re action that cannot be predicted from clinical variables. (C) 2000 Elsevier Science Inc. All rights reserved.