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

When you're traveling to a region where malaria is common, mefloquine, a prescription antimalarial medication used to prevent and treat malaria caused by Plasmodium parasites. Also known as Lariam, it's one of the few drugs still widely used for long-term protection in areas with resistant strains. Unlike some other malaria pills, mefloquine is taken once a week, which makes it easier to stick with—but it’s not for everyone. If you have a history of seizures, depression, or anxiety, your doctor will likely skip this one. It’s not a casual choice; it’s a calculated one.

Mefloquine works by killing the malaria parasite in your blood after it’s been passed to you by a mosquito bite. It’s often used in parts of Africa, Southeast Asia, and South America where other drugs like doxycycline or atovaquone-proguanil might not work as well. But it’s not just about effectiveness. The real conversation around mefloquine is about its side effects. Some people report vivid dreams, dizziness, or trouble sleeping. In rare cases, it can cause serious neurological or psychiatric reactions—like confusion, hallucinations, or severe anxiety. That’s why the CDC and WHO recommend it only when alternatives aren’t suitable, and why many travel clinics now offer other options first.

It’s also important to know when to start and stop taking it. You usually begin one to two weeks before your trip, keep taking it weekly while you’re there, and continue for four weeks after you return. Missing a dose or stopping early can leave you unprotected. And if you’re buying it overseas, make sure it’s from a trusted source. Fake antimalarials are a real problem in some countries, and taking the wrong pill can be deadly.

There’s a reason you’ll find posts here about tracking drug recalls, managing side effects from diuretics like indapamide, or comparing antibiotics like Bactrim and Cefaclor. Mefloquine fits right into that same conversation: it’s a powerful tool, but it demands awareness. You need to know what you’re taking, why you’re taking it, and what to watch for. This collection doesn’t just list facts—it gives you the real-world context you need to make smart decisions. Whether you’re planning a trip, managing a past reaction, or just trying to understand why your doctor chose this drug over another, you’ll find practical, no-fluff guidance below.