Whole blood hydroxychloroquine: Does genetic polymorphism of cytochrome P450 enzymes have a role?

Hydroxychloroquine Screening Guidelines: Best Evidence, Controversies, and Future Areas of Research

“…They also noted a wide range of blood levels at each prescribed dose, which was partly attributed to differences in adherence, and potential genetic polymorphisms affecting final blood levels. 38 HCQ blood levels may play a potentially useful role in guiding dosing in minority groups mentioned above. For example, one cross-sectional study by Pedrosa and colleagues looked at 108 patients with lupus nephritis who were prescribed HCQ based on the 2016 AAO RBW-based guidelines.…”

“…One prospective cohort study by Petri et al 37 found that more elevated mean and maximum HCQ blood levels (measured by liquid chromatography-tandem mass spectrometry) were predictive of HCQ retinopathy. They also noted a wide range of blood levels at each prescribed dose, which was partly attributed to differences in adherence, and potential genetic polymorphisms affecting final blood levels 38 …”