P008 Hydroxychloroquine-related adverse events, attrition and reasons for cessation over 5 years at a district general hospital: estimating future ophthalmology screening service use

Abstract

Abstract Background/Aims Hydroxychloroquine (HCQ) is used widely in the management of rheumatic diseases and is considered to be generally well tolerated. HCQ ocular toxicity is a dose- and time-related reaction. The Royal College of Ophthalmologists (RCOphth) noted a low rate of drug discontinuation as a result of baseline testing (< 4%) and that prevalence data for HCQ ocular toxicity was based on treatment duration >5 years. The RCOphth updated their ocular toxicity screening guideline in 2020. A major change was removal of requirement for baseline screening, with screening commenced at 5 years of treatment unless risk factors are present. Though the number of patients starting HCQ treatment and the UK prescribing data could be estimated, the proportion of patients remaining on treatment for >5 years was stated to be unknown. We reviewed departmental HCQ prescribing, adverse event and attrition data over 5 years from Bolton NHS Foundation Trust, a district general hospital which serves a population of nearly 300,000. Methods Patients were identified as newly commencing HCQ if they had a shared care agreement in the calendar year 2016. Adverse events, attrition rates and reasons for cessation were obtained through review of hospital records over 5 years. Results In the 2016 calendar year, 100 patients commenced HCQ. The mean age was 58, and 70% patients were female. The most common indication was rheumatoid arthritis (75%). At 1 year, 30% of patients had stopped taking HCQ. At 5 years 57% of patients had stopped taking HCQ. The most common reason for cessation at 1 year was gastrointestinal symptoms (30%), and remained the most common reason at 5 years (19%). Eye symptoms were documented as reason for cessation in 7% of patients at 1 year, and 5% of patients at 5 years. On review of records, none of these were thought to be attributable to HCQ, though it was not recommenced. There were no patient deaths directly attributable to HCQ use. Conclusion A significant proportion of patients (57%) stopped taking HCQ after 5 years. The rate of attrition was highest within 12 months, which then almost doubled by 5 years. Centres wishing to estimate the workload related to HCQ retinopathy screening can capture their prescribing for patients newly starting HCQ and/or their catchment population numbers to estimate the Ophthalmology activity related to this 5 years' hence. This may help to fund and staff adequately to successfully carry out this drug safety activity. Disclosure D. Barahman: None. C. Saleh: None. A. Paul: None.