It is generally well tolerated, but retinopathy is a concern. Retinopathy is rare, but is sight threatening, generally irreversible and may progress even after cessation of therapy. Although a number of risk factors have been proposed (such as duration of therapy and cumulative dose), the many exceptions (e.g. Chloroquine phosphate and pregnancy Chloroquine still effective for malaria prophylaxis guatamala Evaluation with electroretinogram ERG 5. Determine the frequency of surveillance examinations. For example, if a patient has taken 250 milligrams of plaquenil per day for three years, the cumualtive dose is 273,750 milligrams. This equals 273.75 grams of plaquenil and is below the 1,000 gram threshold for developing toxic maculopathy. Another. The mfERG, first described by Sutter and Tran 24, can be an efficient tool to diagnose spatially restricted retinal disorders and has been shown to be an objective test for functional retinal. Hydroxychloroquine is in a class of drugs called antimalarials. It is used to prevent and treat acute attacks of malaria. It is also used to treat discoid or systemic lupus erythematosus and rheumatoid arthritis in patients whose symptoms have not improved with other treatments. Novel technologies such as optical coherence tomography (OCT), fundus autofluorescence (FAF) and multifocal electroretinogram (mf ERG) may provide the earliest structural and functional evidence of toxicity in these stages. Retinopathy on low-dose HCQ, or no retinopathy after a very large cumulative dose of HCQ) highlight our limited understanding of the disease process. Plaquenil fullfield erg severe Erg eog - SlideShare, Assessing hydroxychloroquine toxicity by the multifocal ERG. Taking plaquenil while having infectionsHydroxychloroquine lichen planopilaris Find user ratings and reviews for Plaquenil oral on WebMD including side effects and drug interactions, medication effectiveness, ease of use and satisfaction Plaquenil oral Reviews and User Ratings Effectiveness, Ease.. Hydroxychloroquine MedlinePlus Drug Information. ERG findings in patients using hydroxychloroquine SpringerLink. At this point, full-field ERG should be considered to exclude diffuse photoreceptor loss. SUMMARY. Hydroxychloroquine is an effective and relatively safe drug that can cause retinal toxicity in a minority of patients. Early diagnosis is important to stop treatment and prevent possible further damage. The electroretinogram ERG. The global or full-field electroretinogram ERG is a mass electrical response of the retina to photic stimulation. The ERG is a test used worldwide to assess the status of the retina in eye diseases in human patients and in laboratory animals used as models of retinal disease. Hydroxychloroquine should be used with extreme caution in patients with psoriasis or porphyria because it has been shown to precipitate severe attacks. Use hydroxychloroquine in patients with these conditions only if the potential benefit to the patient outweighs the possible risk.