Plaquenil, hydroxychloroquine (HCQ), is an anti-malarial medication that has been proven to be useful in the treatment of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and other inflammatory and autoimmune diseases. In Sjögren’s, Plaquenil is used to treat many symptoms of Sjögren’s including fatigue, joint symptoms of arthritis and arthralgias (joint pain), dry mouth and dry eyes. Similar to its use in systemic lupus erythematosus, many clinicians feel that it is useful in reducing general Sjögren’s “disease activity.”
One of the reasons that physicians feel comfortable in prescribing Plaquenil is its low risk to benefit ratio. This means that the side effects of Plaquenil are mild and infrequent compared with its potential benefits. As with any medication, allergic reactions including skin rashes and non-allergic reactions can occur. The side effect that is of greatest concern is retinal toxicity.
Retinal toxicity of Plaquenil may manifest itself with subtle disturbances of the retinal pigment epithelium which may eventually lead to complete destruction of the macula in the form of bull’s-eye maculopathy.
Several risk factors may increase the likelihood of retinal toxicity from Plaquenil such as, age of greater than 60 years, daily dose more than 6.5 mg/kg; use of the drug more than 5 years, obesity, preexisting retinal disease and, renal or liver failure. Early detection of the maculopathy is of critical importance to discontinue Plaquenil in order to stop or slow retinal damage. Unfortunately, clinically evident early structural changes can be subtle and usually preceded by abnormalities in functional tests such as visual field examination, multifocal electroretinography (mfERG), fundus autofluorescence (FA) imaging, and optical coherence tomography.
Recent findings suggest that Plaquenil toxicity can develop among patients that are taking the drug at a daily dose lower than the suggested “safe” dose and/or have been on Plaquenil for shorter than five years. Unfortunately, cessation of Plaquenil intake may not be a remedy since not infrequently, patients will develop objective evidence of progression despite discontinuation of the drug. Thus, the possibility of toxicity should not be disregarded and close monitoring of the ocular findings is required.
As a precaution, patients treated with Plaquenil are advised to get a baseline eye exam prior to starting the drug and then annually thereafter
This information provided by Neil I. Stahl, MD & Tongalp H. Tezel, MD was first printed in the The Moisture Seeker, SSF's patient newsletter for members.