Hydroxychloroquine

How it works

Hydroxychloroquine accumulates in lysosomes and interferes with antigen processing and toll-like receptor signalling, producing immunomodulatory and anti-inflammatory effects that reduce lupus disease activity.

Prescribing in practice

• It is regarded as compatible with pregnancy and breastfeeding and stopping it abruptly can precipitate a maternal lupus flare, so continuation is usually advised after specialist discussion.
• Long-term use carries a risk of irreversible retinal toxicity, warranting baseline and periodic ophthalmic screening.
• Rare cardiac conduction effects and QT prolongation can occur, with caution where other QT-prolonging drugs are co-prescribed.

Monitoring

Arrange retinal screening per ophthalmology recommendations for long-term users and monitor maternal disease activity through the pregnancy.

Counselling the patient

• Keep taking this medicine in pregnancy unless your specialist tells you otherwise, as stopping can worsen your condition.
• Attend your eye screening appointments and report any change in vision.
• It is taken regularly to control your condition rather than for immediate symptom relief.

Evidence & guidelines

Rheumatology and obstetric guidance supports continuing hydroxychloroquine in pregnancy for lupus, reflecting evidence that it reduces flares and adverse pregnancy outcomes.