For patients · Medication guide

Hydroxychloroquine

Plaquenil, HCQ, antimalarial

Are you a clinician? See the clinical version of this page.

The short versionHydroxychloroquine is the foundation medicine for lupus, and nearly everyone with lupus is advised to take it unless there is a reason they cannot. It calms the overactive immune process behind the disease, lowers the chance of flares, and protects organs over the long term. It is taken by mouth and works slowly, so it can take weeks to months to feel the full benefit.
How you take it

Taken as tablets with food or a glass of milk. It works slowly, over weeks to a few months. Because a rare but serious effect on the eyes is dose-related, the dose is kept in a safe range for your body weight and you will have regular eye checks.

It can take 4 to 12 weeks, sometimes longer, to feel the benefit.

Tests while you take it

You should have a baseline eye exam within the first year, then yearly eye checks after 5 years of use (sooner if you have kidney problems or take certain other medicines). Report any change in vision.

What to know

How it is used in lupus

Hydroxychloroquine is recommended for nearly everyone with lupus and is usually taken for the long term, even when the disease is quiet, because stopping it makes flares more likely. Please do not stop it on your own; talk with your rheumatologist first.

Common side effects

Most people tolerate it well. The more common effects are mild stomach upset and, less often, skin rash or changes in skin colour. Serious effects are uncommon, but long-term use carries a small risk of changes at the back of the eye, which is why regular eye checks matter.

Tests and monitoring

You will have blood tests for your blood counts, liver, and kidneys before you start and from time to time after that. Because the medicine can rarely affect the retina at the back of the eye, you also need an eye check when you start, then a yearly eye screen beginning no later than 5 years of use. If you have a heart rhythm condition, you may also have a heart tracing (ECG).

Important cautions

Hydroxychloroquine is one of the few lupus medicines usually continued right through pregnancy and breastfeeding, and staying on it is often encouraged. Your reviewed pregnancy guidance is on the separate pregnancy page. Tell your team if your vision changes.

+Planning a pregnancy? This medicine has separate, reviewed reproductive-health guidance. See the pregnancy guide for this medicine.
iThis page helps you prepare a conversation with your care team. It does not replace individual medical advice. Always confirm your own plan with your rheumatology team.
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What to watch for