Importance for patients with CKD
Many patient factors can affect how the body absorbs HCQ, Dr. Garg said, so finding the right level that is safe and maximizes benefit individually is important.
The findings are particularly important for patients with chronic kidney disease (CKD) of stage 3 or higher, Dr. Garg said.
The authors write that because kidneys clear more than half of all HCQ, impaired kidney function could boost HCQ blood levels, risking toxicity.
“Our study found a sixfold higher odds of having supratherapeutic HCQ blood levels in patients with CKD stage ≥ 3,” they write.
Dr. Garg added that if blood levels cannot be analyzed in all patients, they could be prioritized in patients with CKD stage 3 or above because these patients are at “higher risk of being underdosed with arbitrary reductions in HCQ doses and carry higher risk of toxicity if HCQ doses are not adjusted.”
More research will uncover other high-risk groups who would benefit most from close monitoring of HCQ blood levels, she said.
The study was supported by an award from the University of Wisconsin–Madison, and by an award to the institution from the National Institutes of Health National Center for Advancing Translational Sciences. Dr. Garg and coauthors as well as Dr. Petri report no relevant financial relationships.
A version of this article first appeared on Medscape.com.