Hydroxychloroquine

Key points

• Hydroxychloroquine is used in the management of rheumatoid arthritis and systemic/discoid lupus erythematosus; pharmacologically similar to chloroquine (used to treat certain types of malaria)
• Key adverse effect: bull's-eye retinopathy, which may cause severe and permanent visual loss
• RCOphth monitoring recommendations (2018, revised 2020): a BASELINE retinal assessment ideally within 6 months and definitely within 12 months of starting, then ANNUAL screening from 5 years of therapy onwards · the tests used are colour retinal photography and spectral-domain OCT
• Retinopathy is more common than previously thought — around 7.5% of long-term users, rising with dose and duration · risk is increased by doses above 5 mg/kg/day, concurrent tamoxifen, and renal impairment · stopping the drug is the only intervention that prevents further damage
• BNF advice: ask about visual symptoms and monitor visual acuity annually using a standard reading chart