If you or someone you know is taking Lariam (mefloquine) for malaria prevention, you probably wonder what side effects to expect. Knowing the typical reactions and the rare but serious ones can help you stay safe and act fast if something goes wrong.
Most people feel only mild issues. The most frequent complaints are stomach upset, nausea, and loss of appetite. Some users get headaches, dizziness, or trouble sleeping. You might also notice dry mouth or a metallic taste. These symptoms usually start in the first few days and fade within a week or two.
If you notice a rash, mild itching, or a feeling of being “off,” keep an eye on it. In many cases it clears up without extra treatment, but you should tell your doctor if it sticks around.
While the common side effects are annoying, certain reactions need a doctor’s attention right away. Watch for severe dizziness, confusion, or any changes in mood like anxiety, depression, or strange thoughts. Hallucinations, panic attacks, or sudden aggression are red flags.
Heart‑related symptoms such as a fast or irregular heartbeat, chest pain, or shortness of breath also require immediate care. If you develop a high fever, persistent vomiting, or severe abdominal pain, call your health provider.
Women who are pregnant, breastfeeding, or planning to become pregnant should talk to a doctor before starting Lariam. Some studies link the drug to fetal issues, so professional guidance is key.
People with a history of mental health problems, epilepsy, or heart disease are at higher risk for serious side effects. Let your doctor know about any past conditions, even if they seem unrelated.
To reduce the chance of side effects, take Lariam exactly as prescribed. Swallow the tablet with a full glass of water, ideally with food to lessen stomach upset. Avoid alcohol while you’re on the medication, as it can worsen dizziness and nausea.
If you miss a dose, take it as soon as you remember unless it’s close to the next dose. In that case, skip the missed one—don’t double up.
Storing Lariam at room temperature, away from direct sunlight, helps keep it stable. Keep it out of reach of children.
When you finish the course, follow up with your doctor, especially if any lingering symptoms persist. Sometimes a short taper or a switch to a different malaria drug is needed.
Bottom line: most users experience only mild, short‑lived effects, but serious reactions can happen. Knowing what to watch for, staying in touch with your health team, and taking the pill correctly makes the safest experience possible.
Learn what Lariam is, how it prevents malaria, proper dosing, common side effects, and safety advice for travelers in a clear, practical guide.