Hydroxychloroquine vs Chloroquine: Key Differences and Uses

When it comes to treating malaria and certain autoimmune diseases, hydroxychloroquine, a modified version of chloroquine with a better safety profile. Also known as Plaquenil, it's commonly used for lupus and rheumatoid arthritis. chloroquine, the original compound developed in the 1930s. Also known as Aralen, it’s still used in some parts of the world for malaria but has largely been replaced by hydroxychloroquine in the U.S. and Europe due to its higher risk of eye damage. Both drugs belong to the same family—4-aminoquinolines—and work by interfering with how parasites and immune cells function. But they’re not interchangeable, and the choice between them can affect your safety and outcomes.

The biggest difference lies in how your body handles them. Hydroxychloroquine stays in your system longer and builds up more slowly, which means fewer severe side effects. Chloroquine hits harder and faster, making it more effective against some malaria strains—but also more dangerous. Long-term use of chloroquine carries a much higher risk of retinal toxicity, which can lead to permanent vision loss. That’s why doctors now prefer hydroxychloroquine for chronic conditions like lupus, even though it’s slightly less potent against malaria. For travel to high-risk areas, chloroquine might still be recommended if the local malaria parasite hasn’t developed resistance—but that’s becoming rare. In fact, most malaria strains today are resistant to both drugs, so they’re no longer first-line for prevention or treatment in many countries.

Both drugs are also used off-label for autoimmune conditions, but hydroxychloroquine is the clear winner here. It’s the go-to for reducing joint pain, skin rashes, and fatigue in lupus patients. Studies show it can even lower the risk of flares and blood clots in these patients. Chloroquine is rarely prescribed for this anymore because of its toxicity profile. What’s more, hydroxychloroquine interacts less severely with other common medications like statins or blood pressure pills. If you’re on multiple drugs, that matters. Neither drug is safe to take without medical supervision, and both require regular eye exams if used long-term. But if you’re comparing them side by side, hydroxychloroquine is the safer, more modern choice for most people.

What you’ll find below are real comparisons and patient experiences from people who’ve used both drugs—some for malaria, others for autoimmune conditions. You’ll see how dosing differs, what side effects actually show up in daily life, and why some doctors still prescribe chloroquine despite the risks. There are also posts about drug interactions, generic availability, and how these meds fit into broader treatment plans. No fluff. Just facts you can use to talk to your doctor or understand your own treatment better.