Antimalarial / DMARD

Hydroxychloroquine sulfate

Brand names: Plaquenil

Adult dose

Dose: 200–400mg/day, max 5 mg/kg/day actual body weight

Route: PO

Frequency: OD or BD

Clinical pearls

RA, SLE, discoid LE
RCOphth: baseline ophthalmic exam at start, screen annually after 5 years (sooner if risk factors)

Contraindications

Pre-existing maculopathy
Hypersensitivity to 4-aminoquinolines
Caution in psoriasis (may worsen), porphyria, G6PD deficiency

Side effects

Retinopathy (dose- and duration-dependent)
GI upset
Skin pigmentation
Pruritus
QT prolongation
Cardiomyopathy (rare, long-term)
Hypoglycaemia

Interactions

Digoxin (raised levels)
Antiepileptics
Antacids (reduce absorption)
QT-prolonging drugs

Monitoring

Annual ophthalmic screening from 5 years
FBC
LFTs

Reference: BNF; NICE NG100 (RA); RCOphth/BSR retinopathy screening guidelines; https://bnf.nice.org.uk/drugs/hydroxychloroquine-sulfate/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways