Chloroquine retinopathy is a form of toxic retinopathy (damage of the retina) caused by the drugs chloroquine or hydroxychloroquine, which are sometimes used in the treatment of autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus. This eye toxicity limits long-term use of the drugs. Presentation
The risk of toxicity is low for individuals without complicating conditions during the first five years of treatment using less than 6.5 mg/kg/day of hydroxychloroquine or 3 mg/kg/day of chloroquine, and/or cumulative doses of less than 1000 gram and 460 gram (total dose), respectively. Some physicians suggest that lean body weight is more accurate when calculating daily dosage.Most patients are routinely given 400 mg of hydroxychloroquine daily (or 250 mg chloroquine). This dose is considered acceptable. Early stage
The earliest signs of toxicity include bilateral paracentral visual field changes (best detected with a red test object) and a subtle granular depigmentation of the paracentral RPE. Advanced stage
With continued drug exposure, there is progressive development of a bilateral atrophic bulls-eye maculopathy and paracentral scotomata, which may in severe cases ultimately spread over the entire fundus, causing widespread retinal atrophy and visual loss. Pathophysiology
Both agents bind to melanin pigment in the RPE, and this may serve to concentrate the drugs or to prolong their adverse effects. Diagnosis
Patients and their primary care physicians must be made fully aware of the ophthalmic risks and the need for regular screening examinations to detect retinal toxicity at an early stage.
Belinostat (trade name Beleodaq, previously known as PXD101) is a histone deacetylase inhibitor drug developed by TopoTarget for the treatment of hematological malignancies and solid tumors.It was approved in July 2014 by the US FDA to treat peripheral T-cell lymphoma.In 2007 preliminary results were released from the Phase II clinical trial of intravenous belinostat in combination with carboplatin and paclitaxel for relapsed ovarian cancer. Final results in late 2009 of a phase II trial for T-cell lymphoma were encouraging. Belinostat has been granted orphan drug and fast track designation by the FDA, and was approved in the US for the use against peripheral T-cell lymphoma on 3 July 2014. It is not approved in Europe as of August 2014.The approved pharmaceutical formulation is given intravenously. : 180   Belinostat is primarily metabolized by UGT1A1; the initial dose should be reduced if the recipient is known to be homozygous for the UGT1A1*28 allele. : 179 and 181 


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