What are the side effects of Mefloquine (Lariam)?

From the Guidelines

Mefloquine can cause several side effects, including vomiting, dizziness, and neuropsychiatric effects, and its use is typically reserved for cases where first and second-line treatments are contraindicated or not available, as stated in the most recent guidelines 1.

Common Side Effects

• Vomiting
• Dizziness
• Neuropsychiatric effects, such as anxiety, paranoia, depression, hallucinations, and psychosis

Less Common Side Effects

• Vivid dreams or nightmares
• Insomnia
• Balance problems
• Heart rhythm abnormalities

Important Considerations

• Mefloquine is not recommended for patients with a history of neuropsychiatric disorders, seizure disorders, or heart rhythm problems 1.
• The drug should be used with caution in patients with liver impairment, as stated in earlier guidelines 1.
• If symptoms such as mood changes, anxiety, restlessness, or confusion occur, patients should contact their healthcare provider immediately.

Treatment Guidelines

• Mefloquine is considered a third-line treatment for uncomplicated malaria in adults in non-endemic settings, according to the most recent guidelines 1.
• The recommended dosage is 3 tablets (750 mg salt) on the first day, followed by 2 tablets (500 mg salt) after 8-12 hours.

From the FDA Drug Label

Mefloquine can cause serious side effects, including:

1. Heart Problems.
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 • feeling confused
3. Problems with your body’s nervous system 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 sound in your ears (tinnitus) • convulsions (seizures) in people who already have seizures (epilepsy) • convulsions (seizures) in people who take quinine or chloroquine (used to treat malaria) with mefloquine • Unable to sleep (insomnia) Mefloquine may cause serious side effects, including: • liver problems 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

The side effects of mefloquine include:

• Heart problems: such as QT prolongation, which can lead to death
• Mental problems: such as severe anxiety, paranoia, hallucinations, depression, and suicidal thoughts
• Nervous system problems: such as dizziness, vertigo, loss of balance, tinnitus, convulsions, and insomnia
• Liver problems
• Common side effects: such as nausea, vomiting, diarrhea, abdominal pain, headache, muscle pain, fever, chills, skin rash, fatigue, loss of appetite, and irregular heart beat 2 2

From the Research

Side Effects of Mefloquine

• Mefloquine has been associated with rare but severe neuropsychiatric adverse reactions, including anxiety, depression, hallucinations, and psychosis 3, 4.
• Common neuropsychiatric adverse effects of mefloquine can occur in up to 40% of patients, such as dizziness, sleep disturbances, anorexia, ataxia, and fatigue 4.
• More serious adverse reactions are rare, but can include panic attacks, convulsions, acute psychosis, paranoid delusions, suicidal ideation, and disorders of mood: major depressive episode and manic excitation 4.
• The incidence of such neuropsychiatric effects is 1/10,000 to 1/15,000 during prophylactic treatment 4.
• Risk factors for mefloquine-induced neuropsychiatric toxicity include a personal or family history of psychiatric disorders, alcohol consumption, and concomitant use of other drugs such as quinine 4.

Neuropsychiatric Adverse Reactions

• Mefloquine can cause serious and potentially lasting neuropsychiatric adverse reactions, including psychiatric and neurologic symptoms 5.
• Drug regulators have required updates to mefloquine labels to warn that the drug should be discontinued at the onset of neurologic or psychiatric symptoms 5.
• A systematic comparison of international drug safety labeling found complete or partial agreement in prescribing and patient recommendations for reactions in 11 (50%) of 22 neuropsychiatric high level group terms 6.

Comparison with Other Antimalarial Drugs

• Accumulating data have indicated that mefloquine is the only commonly used antimalarial drug that has clear indications of serious neurological and/or psychiatric side effects 7.
• A more systematic approach to assess the neuropsychiatric adverse effects of new or repurposed antimalarial drugs is needed to ensure that these life-saving tools remain available and can be prescribed with appropriate caution and medical judgment 7.