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Antimalarial / Immunomodulator (Obstetric Use) Pregnancy: Safe in pregnancy — extensive data from SLE pregnancies; benefit outweighs theoretical risk; neonatal drug exposure is low

Hydroxychloroquine

Brand names: Plaquenil

Adult dose

Dose: 200-400 mg once daily (max 5 mg/kg/day ideal body weight)
Route: Oral
Frequency: Once daily or divided twice daily
Max: 400 mg/day (or 5 mg/kg/day ideal body weight — whichever is lower — to reduce retinopathy risk)
SLE in pregnancy, antiphospholipid syndrome (APS), Sjögren's syndrome in pregnancy; should be continued throughout pregnancy — abrupt discontinuation significantly increases SLE flare risk

Paediatric dose

Dose: 5 mg/kg/day mg/kg
Route: Oral
Frequency: Once daily
Max: 400 mg/day
Paediatric SLE (specialist use)

Dose adjustments

Renal

No dose adjustment for mild-moderate impairment; use with caution in severe renal impairment

Hepatic

Use with caution in hepatic impairment — hepatic metabolism

Paediatric weight-based calculator

Paediatric SLE (specialist use)

Clinical pearls

  • Hydroxychloroquine in SLE pregnancy: reduces disease flare rate, neonatal lupus incidence (particularly congenital heart block in anti-Ro/La antibody-positive mothers — NEJM 2020 hydroxychloroquine trial for neonatal lupus prevention), and preterm birth risk — should be continued throughout pregnancy and not stopped peripartum
  • MHRA retinopathy screening protocol: baseline ophthalmological examination before or at initiation, then annual screening after 5 years of use (or earlier if risk factors: renal impairment, high dose, pre-existing macular disease) — cumulative dose >5 mg/kg/day is the key risk factor
  • Antiphospholipid syndrome in pregnancy: hydroxychloroquine used as adjunct alongside low-dose aspirin + LMWH in refractory obstetric APS — reduces thrombotic risk and improves placental function
  • Neonatal lupus: anti-Ro/SSA antibody-positive mothers have 2% risk of complete congenital heart block — hydroxychloroquine reduces this risk (PATCH trial data); fetal cardiac monitoring (weekly ECG from 16-26 weeks) recommended regardless
  • COVID-19 clinical trials (RECOVERY 2020, SOLIDARITY WHO): hydroxychloroquine showed no benefit and potential harm in COVID-19 — reinforces that its therapeutic benefits are immunomodulatory (SLE/APS), not antiviral

Contraindications

  • Pre-existing retinopathy
  • Known hypersensitivity to 4-aminoquinolines
  • Caution in G6PD deficiency

Side effects

  • Retinopathy (dose and duration dependent — MHRA mandatory ophthalmological screening)
  • Nausea/GI upset (take with food)
  • Headache
  • Rash
  • QTc prolongation (less than chloroquine)
  • Myelosuppression (rare)

Interactions

  • QTc-prolonging drugs — additive risk; avoid with azithromycin, antipsychotics
  • Antiepileptics — hydroxychloroquine may lower seizure threshold
  • Ciclosporin — hydroxychloroquine increases ciclosporin levels; monitor

Monitoring

  • Annual ophthalmological exam (retinal OCT after 5 years)
  • FBC (periodically)
  • Fetal cardiac monitoring if anti-Ro/La positive
  • SLE disease activity (SLEDAI)
  • Complement levels (C3/C4), anti-dsDNA

Reference: BNFc; BNF 90; MHRA hydroxychloroquine retinopathy guidance 2020; Izmirly et al. NEJM 2020 (PATCH trial); BSR/BHPR SLE in Pregnancy Guideline (2022); EULAR APS Guidelines (2019). Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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