- Hydroxychloroquine (HCQ) is an antimalarial drug that can be administered orally to treat conditions like malaria, lupus, and rheumatoid arthritis. - It is absorbed rapidly in the gastrointestinal tract, distributed widely in tissues, and eliminated mainly through the kidneys. The half-life is 32-50 days. - HCQ works by accumulating in lysosomes and increasing their pH. This blocks toll-like receptors on dendritic cells and reduces inflammation. - Potential side effects include nausea, diarrhea, skin rash, retinopathy, and cardiac issues. It can interact adversely with some medications like insulin, digoxin, and antacids. Overdose may