Mefloquine (neuropsychiatric adverse reactions)

• the prevalence of neuropsychiatric adverse reactions is between 1 in 10,000 and 1 in 20,000 users of prophylactic mefloquine
• risk is generally higher in females than males
• mefloquine is contraindicated in patients at risk of seizures, epilepsy or psychiatric disease
• mefloquine chemoprophylaxis should be used with caution in airline pilots
• neuropsychiatric adverse reactions account for about 1/4 of side-effects associated with mefloquine
  • 41% of neuropsychiatric adverse reactions occur within one week of starting to take mefloquine
  • 69% of neuropsychiatric adverse reactions occur within two weeks of starting to take mefloquine
  • 78% of neuropsychiatric adverse reactions occur within three weeks of starting mefloquine chemoprophylaxis
• the commonest symptoms are:
  • vertigo, dizziness and headaches
  • mood changes are a frequently reported symptom
• serious adverse reactions include psychotic episodes, seizures, ataxia, hallucinations and depression

Roche have stated that (3):

• Lariam (mefloquine) may induce potentially serious neuropsychiatric disorders
  
  
• the most common neuropsychiatric reactions to mefloquine include abnormal dreams, insomnia, anxiety, and depression. Additionally hallucinations, psychosis, suicide, suicidal thoughts and self-endangering behaviour have been reported
  
  
• do not use mefloquine for malaria chemoprophylaxis in patients with any active or a history of psychiatric disturbances
  
  
• due to the long half-life of mefloquine, adverse reactions may occur and persist up to several months after discontinuation of the drug
  
  
• healthcare professionals should react promptly to signs of neuropsychiatric reactions with mefloquine chemoprophylaxis. Mefloquine should be discontinued immediately and replaced by alternative malaria prophylaxis medication
  
  
• advise patient that if they experience a neuropsychiatric reaction such as suicidal thoughts; self-endangering behaviour; severe anxiety; feelings of restlessness, confusion, or mistrust towards others; visual/auditory hallucinations; depression; or changes to their mental state during mefloquine chemoprophylaxis, they should stop taking mefloquine immediately and seek urgent medical advice

Reference:

• Prescribers' Journal (1999), 39 (3), 161-5.
• Health protection agency 2007. Guidelines for malaria prevention in travelers from the United Kingdom
• Roche (October 2013). Direct Helathcare Professional Communication on Larium (mefloquine) for malaria chemoprophylaxisis and the risk of neuropsychiatric adverse reactions