Pattern of Retinopathy: Although the locus of toxic damage is parafoveal in many eyes, Asian patients often show an extramacular pattern of damage. Dose: We recommend a maximum daily HCQ use of 5.0 mg/kg real weight, which correlates better with risk than ideal weight. Chloroquine and quinine are commonly used to treat Treatment of cutaneous lupus erythematosus with acitretin and hydroxychloroquine Enantiomer-specific analysis revealed genotype-dependent enantio-selective metabolism, with nearly 40% greater R- vs S-metoprolol metabolism in ultra-rapid and extensive metabolizers. This study demonstrates a marked effect of CYP2D6 metabolizer phenotype on metoprolol pharmacokinetics and confirms enantiomer specific metabolism of metoprolol. The cytochrome P450 2D6 CYP2D6 enzyme is predominantly involved approximately 70-80% in the hepatic metabolism of metoprolol. 1, 2 Since the first description of a CYP2D6 sparteine-debrisoquin polymorphism in the mid-1970’s, substantial genetic heterogeneity has been reported with close to 100 different polymorphisms identified. Hydroxychloroquine is a well-tolerated medication for various rheumatologic and dermatologic conditions. Its main side effects are gastrointestinal upset, skin rash, headache, and ocular toxicity1. Within the eye, hydroxychloroquine can adversely impact the cornea, ciliary body, and retina1 Risk of Toxicity: The risk of toxicity is dependent on daily dose and duration of use. There are no similar demographic data for CQ, but dose comparisons in older literature suggest using 2.3 mg/kg real weight. Hydroxychloroquine metabolism cyp Cytochrome P450 - Wikipedia, META-ANALYSIS OF CYP2D6 METABOLIZER PHENOTYPE AND. Chloroquine and proguanil side effectsProphylaxis of malaria chloroquine Recommendations on Screening for Chloroquine and Hydroxychloroquine Retinopathy Retinal toxicity from chloroquine CQ and its analogue, hydroxychloroquine HCQ, has been recognized for many years. Chloroquine toxicity remains a problem in many parts of the world, but is seen less frequently in the United States where the drug largely has been replaced by HCQ. Recommendations on Screening for Chloroquine and.. Hydroxychloroquine toxicity - EyeWiki. Mechanisms of action of hydroxychloroquine and chloroquine.. Cytochrome P450 CYP is a hemeprotein that plays a key role in the metabolism of drugs and other xenobiotics Estabrook, 2003. Understanding the CYP system is essential for advanced practitioners APs, as the consequences of drug-drug interactions can be profound. Hydroxychloroquine Hydroxyzine Imatinib Levomepromazine Methadone Metoclopramide Mibefradil Midodrine Moclobemide Nefazodone Norfluoxetine Paroxetine Perphenazine Propafenone Propoxyphene Propranolol Quinacrine Quinidine. Cytochrome P450 CYP450 Enzyme Inhibitors Drug Reference Table. The proposed mechanism is inhibition of CYP450 2D6 hepatic metabolism by hydroxychloroquine. In a randomized, double-blind, crossover study, seven healthy subjects with CYP450 2D6 extensive metabolizer phenotypes took 400 mg hydroxychloroquine or placebo twice daily for 8 days, and 100 mg metoprolol orally on the ninth day. Average metoprolol.