Antimalarial DMARD Pregnancy: Considered safe in pregnancy for SLE/RA — stopping increases risk of disease flare.

Hydroxychloroquine

Brand names: Plaquenil

Adult dose

Dose: 200–400 mg once daily (max 5 mg/kg/day ideal body weight)

Route: Oral (take with food)

Frequency: Once or twice daily

Max: 5 mg/kg/day (actual body weight for overweight patients; ideal body weight for all patients)

RA/SLE/Sjögren's: 200–400 mg/day. Dose based on ideal body weight (IBW) to avoid retinopathy — max 5 mg/kg/day IBW. Take with food to reduce GI side effects. Onset of action: 3–6 months.

Paediatric dose

Dose: 5 mg/kg

Route: Oral

Frequency: Once daily

Max: 5 mg/kg/day (max 400 mg/day)

JIA/SLE (≥6 years): 3–5 mg/kg/day (max 5 mg/kg/day — max 400 mg/day). Annual ophthalmology review from start of treatment.

Dose adjustments

Renal

Use with caution; dose reduction may be required in severe renal impairment.

Hepatic

Use with caution in severe hepatic impairment.

Paediatric weight-based calculator

Patient weight (kg)

JIA/SLE (≥6 years): 3–5 mg/kg/day (max 5 mg/kg/day — max 400 mg/day). Annual ophthalmology review from start of treatment.

Clinical pearls

Annual retinal screening (ophthalmology) after 5 years of treatment — or immediately if risk factors
Dose based on ideal body weight to prevent retinopathy — max 5 mg/kg/day IBW
Well tolerated — often used as anchor DMARD alongside MTX in RA (triple therapy)
COVID-19 clinical trials: not shown to be effective
G6PD testing before starting (especially in high-risk populations)

Contraindications

Pre-existing maculopathy or retinal field changes
Hypersensitivity to hydroxychloroquine or chloroquine
G6PD deficiency (haemolysis risk)

Side effects

GI upset (nausea, diarrhoea — take with food)
Retinopathy (toxicity — cumulative dose >1000g or duration >5 years; annual screening)
Rash and skin hyperpigmentation (sun-exposed areas)
Headache
Corneal deposits (reversible)
Haemolysis in G6PD deficiency

Interactions

Antacids — reduce hydroxychloroquine absorption (take 4 hours apart)
Digoxin — increases digoxin levels
QT-prolonging drugs — additive QT prolongation risk
Anti-diabetics — enhanced hypoglycaemic effect

Monitoring

Ophthalmology: baseline then annually from year 5 (or sooner if risk factors)
LFTs and FBC annually
Blood pressure

Reference: BNFc; BNF; BSR Monitoring Guidelines; RCOphth Hydroxychloroquine Guidelines 2020. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways