What are the side effects of Mefloquine (Lariam) for malaria prophylaxis?

From the Guidelines

Mefloquine (Lariam) is associated with significant side effects, including neuropsychiatric effects, and its use for malaria prophylaxis should be carefully considered due to these potential risks. The side effects of Mefloquine can include nausea, vomiting, dizziness, headache, and sleep disturbances such as vivid dreams or insomnia. More concerning are the neuropsychiatric side effects, which can include anxiety, paranoia, depression, hallucinations, and psychosis, as noted in a study published in the BMJ 1. These mental health effects can occur in some users and may persist for months or even years after stopping the medication. Mefloquine can also cause heart rhythm abnormalities in some individuals. Due to these potential serious side effects, patients should be screened for psychiatric conditions, seizure disorders, and cardiac problems before starting mefloquine.

Some key points to consider when prescribing Mefloquine for malaria prophylaxis include:

• The medication is typically taken once weekly (250mg tablet for adults), starting 2-3 weeks before travel to a malaria-endemic area, continuing during the stay, and for 4 weeks after leaving, although specific guidelines may vary 2.
• Mefloquine is not suitable for children and during pregnancy and lactation, and it is expensive, as highlighted in a study published in the BMJ 1.
• Photosensitisation is uncommon but sometimes severe and prolonged, and excessive exposure to sun should be avoided.
• If neuropsychiatric symptoms develop, the medication should be discontinued immediately and an alternative antimalarial used instead.

It's essential to weigh the benefits and risks of Mefloquine for malaria prophylaxis, considering the potential side effects and the individual patient's health status, as recommended by the CDC and other health organizations 3.

From the FDA Drug Label

Mefloquine may cause serious side effects, including: • liver problems Call your healthcare provider right away if you have unexplained symptoms such as nausea or vomiting, stomach pain, fever, weakness, itching, unusual tiredness, loss of appetite, light colored bowel movements, dark colored urine, yellowing of your skin or the white of your eyes The most common side effects of mefloquine include: • nausea • vomiting • diarrhea • abdominal pain • headache The most common side effects in people who take mefloquine for treatment include: • muscle pain • fever • chills • skin rash • fatigue • loss of appetite • irregular heart beat Tell your doctor if you have any side effect that bothers you or that does not go away These are not all the possible side effects of mefloquine. Mefloquine can cause serious side effects, including:

1. Heart problems Do not take halofantrine (used to treat malaria) or ketoconazole (used for fungal infections) with mefloquine or within 15 weeks of your last dose of mefloquine. You may get serious heart problems that can lead to death. Do not take quinine (Qualaquin) or quinidine (used to treat malaria or irregular heart beat) with mefloquine. You may get serious heart problems Mefloquine may cause serious problems with the electrical system of your heart, called QT prolongation.
2. Mental problems. Symptoms of serious mental problems may include severe anxiety, paranoia (feelings of mistrust towards others), hallucinations (seeing or hearing things that are not there), depression, feeling restless, unusual behavior or feeling confused Some people who take mefloquine think about suicide (putting an end to their life). Some people who were taking mefloquine committed suicide. It is not known if mefloquine was responsible for those suicides. If you have any of these serious mental problems you should contact your doctor right away as it may be necessary to stop taking mefloquine and use a different medicine to prevent malaria. 3 Problems with your body’s nervous system. Do not take quinine (Qualaquin) or chloroquine (Aralen) (used to treat malaria) with mefloquine. You may have a greater risk for convulsions (seizures) Symptoms of serious nervous system problems may include dizziness, a feeling that you or things around you are moving or spinning (vertigo), loss of balance, ringing in your ears (tinnitus), convulsions (seizures) in people who already have seizures, or you are unable to sleep (insomnia) These serious mental and nervous system side effects can go on for months or years after mefloquine is stopped or may become permanent in some people.

The side effects of Mefloquine (Lariam) for malaria prophylaxis include:

• Serious side effects: liver problems, heart problems, mental problems, and problems with the body's nervous system
• Common side effects: nausea, vomiting, diarrhea, abdominal pain, headache, muscle pain, fever, chills, skin rash, fatigue, loss of appetite, and irregular heart beat
• Mental problems: severe anxiety, paranoia, hallucinations, depression, feeling restless, unusual behavior, and suicidal thoughts
• Nervous system problems: dizziness, vertigo, loss of balance, tinnitus, convulsions, and insomnia It is essential to contact a doctor right away if any of these side effects occur, as it may be necessary to stop taking mefloquine and use a different medicine to prevent malaria 4, 5, 6.

From the Research

Mefloquine Side Effects for Malaria Prophylaxis

• The side effects of mefloquine (Lariam) for malaria prophylaxis include: + Abnormal dreams + Insomnia + Anxiety + Depressed mood + Nausea + Dizziness + Discontinuation of the drug due to adverse effects 7
• Compared to atovaquone-proguanil, mefloquine users were more likely to report: + Abnormal dreams (RR 2.04, 95% CI 1.37 to 3.04) + Insomnia (RR 4.42, 95% CI 2.56 to 7.64) + Anxiety (RR 6.12, 95% CI 1.82 to 20.66) + Depressed mood (RR 5.78, 95% CI 1.71 to 19.61) 7
• Compared to doxycycline, mefloquine users were more likely to report: + Abnormal dreams (RR 10.49, 95% CI 3.79 to 29.10) + Insomnia (RR 4.14, 95% CI 1.19 to 14.44) + Anxiety (RR 18.04, 95% CI 9.32 to 34.93) + Depressed mood (RR 11.43, 95% CI 5.21 to 25.07) 7
• The choice of antimalarial agent depends on how individual travelers assess the importance of specific adverse effects, pill burden, and cost 7

Comparison with Other Antimalarial Agents

• Atovaquone-proguanil and doxycycline are the best tolerated regimens, and mefloquine is associated with adverse neuropsychiatric outcomes 8
• Primaquine is the most effective presently available prophylactic for P. vivax malaria and comparable to such regimens as doxycycline, mefloquine, and atovaquone-proguanil for the prevention of P. falciparum malaria 9
• Atovaquone-proguanil appears to provide causal (liver schizont stage) prophylaxis for P. vivax, but is ineffective against late, hypnozoite reactivation-related attacks 10