Mefloquine: What It Is, How It's Used, and What You Need to Know

When traveling to areas where malaria is common, mefloquine, a synthetic quinoline antimalarial drug used to prevent and treat malaria caused by Plasmodium parasites. Also known as Lariam, it's one of the few oral medications that can stop malaria before it starts. Unlike some other antimalarials, mefloquine is taken once a week, which makes it easier to stick with during long trips. But it’s not for everyone — and knowing who it’s right for (and who it’s not) can make all the difference in staying healthy.

Mefloquine works by interfering with the malaria parasite’s ability to break down hemoglobin in red blood cells, which is how it survives and multiplies. It’s mainly used in regions where other drugs like chloroquine have stopped working due to resistance. You usually start taking it one to two weeks before entering a malaria zone, keep taking it weekly while you’re there, and continue for four weeks after leaving. This schedule is critical — missing doses or stopping early can leave you unprotected.

But here’s the catch: mefloquine can cause serious side effects. Some people report dizziness, nausea, or trouble sleeping. Others experience vivid dreams, anxiety, or even mood changes like depression or hallucinations. These aren’t rare — the FDA has issued warnings about neuropsychiatric risks, especially in people with a history of seizures, mental illness, or heart rhythm problems. If you’ve ever had depression, anxiety, or seizures, talk to your doctor before taking it. There are safer options, like doxycycline or atovaquone-proguanil, that don’t carry the same brain-related risks.

It’s also not recommended for pregnant women, children under 5 kg, or people with liver disease. And if you’re planning to fly or operate heavy machinery, mefloquine might not be the best choice — dizziness and balance issues can show up even after you’ve been taking it for weeks.

What you’ll find in the posts below isn’t a list of random drug guides. It’s a focused collection of real-world comparisons and safety checks for medications used in complex health situations. You’ll see how drugs like deflazacort, bicalutamide, and lamotrigine are weighed against alternatives, how dosing changes based on age or condition, and how side effects are managed in practice. Mefloquine fits right in — it’s not just a pill you pop. It’s a decision that requires context, timing, and awareness of your own health history. These articles help you ask the right questions before you take anything — even if it’s meant to keep you safe.