Mefloquine is a prescription antimalarial medication, formerly known as Lariam. It is used to prevent and treat malaria, a serious parasitic disease spread by infected mosquitoes. The medication works by targeting and eliminating malaria parasites in the blood.
Mefloquine for Malaria Prevention
For adults traveling to malaria-risk areas, the dose of mefloquine for prevention is 250 milligrams (mg) taken once a week. The medication should be started at least one to two weeks before entering the area. Pediatric dosing is determined by a child’s weight:
Children weighing over 45 kg receive the adult dose.
Those between 30-45 kg take 187.5 mg weekly.
Those between 20-30 kg take 125 mg weekly.
Those between 10-19 kg take 62.5 mg weekly.
Children weighing 5-9 kg receive 5 mg per kg of body weight weekly.
Continue taking mefloquine weekly during the entire stay in the malaria-risk area. After leaving, continue weekly doses for four additional weeks to ensure effectiveness against any remaining parasites. Taking the tablet with food can help minimize stomach upset. For children, the bitter taste can be masked by crushing the tablet and mixing it with a small amount of sweet food like honey or chocolate syrup. Take the dose on the same day each week.
Mefloquine for Malaria Treatment
For adults, the total dose for malaria treatment is 1250 mg. This can be given as a single dose, or split into two parts: an initial 750 mg dose followed by 500 mg six to twelve hours later. Splitting the dose may help reduce the occurrence or severity of potential side effects.
For children aged six months and older, the treatment dose is based on body weight, 20 to 25 mg per kilogram of body weight. This dose can be given as a single amount or divided into two doses 6 to 8 hours apart. The pediatric dose should not exceed the adult dose. If vomiting occurs within 30 minutes of taking a dose, a full repeat dose should be given; if vomiting occurs between 30 and 60 minutes, an additional half-dose is recommended. Treatment for malaria should be managed by a healthcare professional after a confirmed diagnosis; self-treatment is not advised.
Important Considerations Before Use
Individuals with a history of psychiatric conditions, including active depression, generalized anxiety disorder, psychosis, or schizophrenia, should not take mefloquine. People with a history of seizures or certain heart conditions, such as irregular heartbeat or conduction problems, should also avoid this medication. Mefloquine can exacerbate these conditions.
Mefloquine can cause side effects, particularly neuropsychiatric effects. Common psychiatric reactions include abnormal dreams, insomnia, anxiety, and depression. More serious effects, though rarer, can include hallucinations, paranoia, agitation, confusion, and suicidal thoughts or behavior. These symptoms can begin at any time during treatment and may persist for weeks, months, or even years after discontinuing the drug.
Other common side effects include nausea, vomiting, diarrhea, headaches, dizziness, muscle pain, fever, and skin rash. Taking the medication with food can help lessen gastrointestinal upset. Mefloquine can also interact with other medications, potentially increasing the risk of side effects or affecting how other drugs work. Discuss all current medications with a healthcare provider before starting mefloquine to assess for potential interactions. The decision to use mefloquine should be made in consultation with a healthcare professional who can evaluate individual risks and benefits.