. Author manuscript; available in PMC: 2021 Nov 11.

Published before final editing as: J Rheumatol. 2020 May 11:jrheum.200493. doi: 10.3899/jrheum.200493

Table 1.

Average hydroxychloroquine concentrations in clinical studies compared to lowest target EC50 concentration

Study	Population	Sample Size	Mean (SD) HCQ (mg/L) All Doses	Mean (SD) HCQ (mg/L) 400 mg Dose	Target Plasma HCQ (mg/L) EC50 0.72 uM
Balevic¹⁵ (serum)	Pregnant adults, rheumatic diseases (North America)	50	0.305-0.424 (0.193-0.261)	0.319- 0.441 (0.195-0.281)	0.48
Balevic (serum)	Children, systemic lupus (North America)	131	Baseline: 0.3 (0.229); 12-month: 0.287 (0.211)	N/A
Morita¹³ (plasma)	Adults, cutaneous or systemic lupus (Japan)	90	0.136-0.197 (0.045-0.079)	0.192 (0.046)
Mok¹⁴ (serum)	Adults, systemic lupus (China)	276	0.202-0.437 (0.152-0.281)	0.437 (0.281)

EC50: half-maximal effective concentrations; HCQ: hydroxychloroquine; SD: standard deviation; uM: micro-molar