Analysis of HCQ dosing, suggesting that high initial doses followed by low and sparse doses may offer significant benefits to patients by decreasing the viral load without reaching levels considered to produce adverse effects.
For instance, the dosing scheme proposed for a 70kg adult with moderate COVID-19 symptoms would be 600mg upon diagnosis, 400mg after 12h, 300mg after 24h, 200mg after 36h, followed by 200mg BID for 4 days, followed by 200mg OD for 5 days.
Suboptimal dosing regimens that do not fully account for the long half-life of HCQ or the patient characteristics are likely contribute to either limited efficacy where therapeutic levels take too long to reach, or significant adverse effects due to excessive dosage.
Karatza et al., 9/16/2020, peer-reviewed, 4 authors.