Table 2.
Parameter | Chloroquine | Hydroxychloroquine |
---|---|---|
Discovery year | 1934 | 1946 |
Basic compound | 4-aminoquinoline | 4-aminoquinoline |
Drug class | Anti-malarial | Anti-malarial |
Drug formula | C18H26ClNO3 | C18H26ClNO3O |
Molecular weight | 320 g/mol | 336 g/mol |
Chemical nature | Weak base | Weak base |
Salt for therapeutics | Phosphate | Sulfate |
Availability | 250 mg (150 mg base); 500 mg (300 mg base) |
200 mg (155 mg base) |
Brand name | Aralen (US) | Plaquenil (US) |
Absorption | Upper intestinal tract; 2–4 hr; 89%; not affected by food |
Upper intestinal tract; 2–4 hr; 74%; not affected by food |
Bioavailability | 0.7–0.8 | 0.7–0.8 |
Distribution | Large: 60 000 L | Large: 47 257 L |
Terminal half-life | 45 ± 15 d | 41 ± 11 d |
Residence time | ≈ 900 h | ≈ 1300 h |
Metabolism | Unmetabolized 62%; rest is dealkylated in liver; enzyme cytochrome 450; active metabolite desethylchloroquine 39% |
Unmetabolized 58%; rest is dealkylated in liver; enzyme cytochrome 450; active metabolites desethylchloroquine (18%) and desethylhydroxychloroquine (16%) |
Clearance | Kidney (51%) and liver | Kidney (21%) and liver |
Toxicity | ||
Animal | 2–3 times more toxic than chloroquine (albino rats) | Safer |
Cardiac | Same | Same |
Ophthalmic | More (≈ 20% in 5–7 years) | Less (≈ 1% in 5–7 years) |
Drug-drug interaction | Same | Same |
Pregnancy and lactation | Safe | Safe |
Indication | ||
Malaria treatment | Yes | Yes |
Malaria prophylaxis | Yes | Yes |
Rheumatology | Not recommended | Drug of choice |
Status for COVID-19 | ||
In vitro antiviral activity | Less potent in vitro | Hydroxychloroquine is more potent in vitro than chloroquine |
Treatment | Used in studies | Used in studies |
Prophylaxis | - | Yes (ICMR) |