Aims: Recent epidemiologic studies have examined the risk of maculopathy with pentosan polysulfate sodium (PPS), a drug indicated for the treatment of interstitial cystitis. However, results have been contradictory. Thus, we quantified the risk of maculopathy with PPS with a focus on risk with duration of use.
Methods: We used a new user, retrospective cohort study with an active comparator. We created a cohort of mutually exclusive 6221 PPS users and 89 744 amitriptyline users, a tricyclic antidepressant also used for the treatment of pain secondary to interstitial cystitis. Subjects were selected from the PharMetrics Plus database (IQVIA, Durham, NC) from 2006 to 2020. Cohort members were followed to the first event of the study outcome (maculopathy) or end of enrolment. A Cox regression model was constructed to adjust for potential confounders.
Results: The mean follow-up was 3.0 years for PPS users and amitriptyline users. The adjusted hazard ratio (HR) for maculopathy in PPS users was 2.64 (95% confidence interval [CI]: 1.90-3.68). The HR for the sensitivity analysis that combined maculopathy and age-related macular degeneration (AMD) was 1.38 (95% CI: 1.16-1.65). A cumulative duration-response pattern was observed, with use greater than 3 years having a 9.5-fold risk of maculopathy (HR = 9.56, 95% CI: 3.60-25.37) compared to a 2.3-fold risk of maculopathy with use for 1 year or less (HR = 2.27, 95% CI: 1.50-3.43). The number needed to harm for the first 4 years of use was 250.
Conclusions: The results of this study suggest an increased risk of maculopathy with PPS use, particularly with longer duration of use.
Keywords: drug toxicity; epidemiology; interstitial cystitis; maculopathy; pentosan polysulfate sodium.
© 2022 British Pharmacological Society.