The nurse monitors for which adverse effect in a client with systemic lupus erythematosus (SLE) who is taking hydroxychloroquine?

Retinal toxicity is the most serious and well-documented adverse effect associated with long-term hydroxychloroquine use. Hydroxychloroquine, an antimalarial drug commonly prescribed for systemic lupus erythematosus and rheumatoid arthritis, can accumulate in the retinal pigment epithelium over time, leading to irreversible damage known as hydroxychloroquine-induced retinopathy or bull's-eye maculopathy. Because the damage can be permanent and may progress even after the drug is discontinued, routine ophthalmologic examinations — typically annually after the first five years of use — are recommended for all clients on this medication. Ototoxicity is not a primary concern with hydroxychloroquine, though it is associated with aminoglycosides and quinine derivatives. Renal toxicity is not a recognized adverse effect of hydroxychloroquine. Pulmonary fibrosis is associated with other agents used in rheumatologic conditions, such as methotrexate and amiodarone, but not with hydroxychloroquine. Students sometimes confuse hydroxychloroquine's side-effect profile with other anti-rheumatic drugs, but the defining surveillance requirement for this medication is regular eye examinations to detect early retinal changes before irreversible vision loss occurs.