Hydroxychloroquine: what to know and how to stay safe

Hydroxychloroquine (often called HCQ) treats autoimmune conditions like lupus and rheumatoid arthritis. It can help control symptoms, but it also has specific risks you should watch for—especially when starting or stopping the drug. This page gives clear, practical steps you can use right away.

Who needs monitoring and which tests matter

If you take HCQ long term or stop it suddenly, you need a simple plan. Start with a baseline visit: tell your doctor about other medicines, heart problems, kidney issues, or vision changes. Common baseline tests include a complete blood count (CBC), liver function tests (LFTs), basic kidney tests (creatinine), and electrolytes. If you take other QT‑prolonging drugs or have heart disease, ask for an ECG before changes.

Eye safety is a big deal with HCQ. Get an eye exam within the first year on the drug. If your daily dose is higher than 5 mg per kg of real body weight, or you have kidney disease or take tamoxifen, you may need earlier and more frequent retinal screening. Most people without risk factors can move to annual eye checks after five years, but follow your ophthalmologist’s advice.

Stopping HCQ: what to watch for and how to act

Don’t stop HCQ on your own. The drug sticks around in the body for weeks, so some effects continue after you stop. If your doctor decides to stop it, ask what symptoms to expect and which labs you’ll get and when. A common plan is to recheck basic blood tests within two to four weeks and earlier if you have new symptoms.

Seek urgent care if you get sudden visual changes (blurry vision, loss of central vision), signs of heart trouble (fainting, rapid irregular heartbeat), severe rash, or breathing problems. For mild side effects—nausea, headache, mild muscle aches—track them in a daily note and report patterns to your prescriber.

Make a habit of keeping a current medication list and sharing it at every visit. Over‑the‑counter drugs, herbal remedies, and supplements can interact or worsen side effects. If you’re switching to another treatment for your condition, ask how the new drug compares and whether extra monitoring is needed.

Want more detail? Our guide on monitoring side effects and lab tests when stopping hydroxychloroquine walks through specific timelines, eye exam details, and real examples of monitoring plans. Use that if you need step‑by‑step checks to share with your doctor.

Final practical tip: bring a written list of symptoms and all medicines to appointments, get baseline labs and an eye exam, and call your clinician right away for sudden vision or heart symptoms. Staying informed makes HCQ safer and keeps your treatment on track.