Lariam® (mefloquine): everything there is to know about this antimalarial

What is malaria?

Malaria is a disease caused by a parasite of the genus Plasmodium, essentially transmitted to humans by the bite of a mosquito, itself infected after biting an infected person. The female mosquito injects the parasite into her host while drinking the blood she needs to lay her eggs. Male mosquitos do not bite.

In 2017, there were an estimated 219 million cases of malaria worldwide.

Malaria has spread to 91 countries around the world, particularly in the tropical areas of Africa, Latin America and Asia.

Contamination between two individuals is only possible in the following cases:

• From a pregnant woman to her child, via the placenta,
  
• Via blood transfusion, from an infected person to another. People who have travelled to an area where malaria is circulating cannot temporarily donate blood.
  

In people who have not been immunised against malaria, symptoms may appear between 8 and 30 days after the bite. These symptoms include:

• fever,
  
• headaches,
  
• muscle aches,
  
• general weakness,
  
• vomiting,
  
• diarrhoea,
  
• coughing.
  

Typical cycles of alternating fever, intense sweating and trembling may occur.

When travelling to an endemic area, one must take precautions to prevent malaria. It is necessary to see a doctor who will instruct you on how to avoid being bitten by mosquitos (long clothing, repellents, mosquito nets, etc.), and prescribe anti-malarial drugs.

What is mefloquine (Lariam®) and why is it prescribed? 

There are various antimalarial drugs that may be used during a trip to an endemic zone, or for treating the already present infection.

Preventive treatment (medical prescription is mandatory) depends on the country, the duration of the trip and the person who is travelling (medical history, age, intolerances, etc.).

Lariam® is an antimalarial drug containing mefloquine. It is marketed in a tablet form and its mode of action is based on the eradication of 4 types of parasite responsible for malaria: Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae and Plasmodium ovale.

It is indicated as a preventive treatment against malaria and should be taken 10 days before travelling to a malaria-endemic area. It is used as a last resort when other available drugs are contraindicated or ineffective against the parasite due to its resistance.

Before prescribing this medication, the doctor must ensure that the benefits of Lariam® outweigh the risks of taking it.

In addition, this treatment can be prescribed as a cure for malaria when the disease has been contracted in an area where the parasite is resistant to chloroquine.

What are the side effects of mefloquine (Lariam®)? 

Side effects frequently reported after taking Lariam® include vomiting, nausea, abdominal pain, diarrhoea and dizziness. These side effects mainly appear at the start of treatment.

Lariam® can also cause skin rashes, associated with itching, as well as more serious reactions such as anaphylactic shock, which can be life-threatening if not treated quickly. Anaphylactic shock is a medical emergency.

Lariam® can also cause respiratory problems such as difficulty breathing or lung infection, as well as cardiovascular problems, visual disturbances, muscle damage, burns and tingling of the skin.

If you notice one or more of these symptoms after taking Lariam®, you should contact your doctor as soon as possible.

In addition, neuropsychiatric side effects have been reported, such as:

• anxiety and depression,
  
• abnormal dreams and nightmares,
  
• panic attacks,
  
• mental confusion,
  
• mood swings,
  
• hallucinations,
  
• psychosis,
  
• paranoia
  
• suicidal thoughts, etc.
  

If you experience neuropsychiatric effects, it is recommended that you discontinue treatment and see a doctor as soon as possible. These symptoms may last from several months to several years after the last treatment dose.

What are the alternatives to mefloquine (Lariam®)? 

Chemoprophylaxis (disease prevention) with mefloquine (Lariam®) is a less widely used therapeutic solution than the atovaquone/proguanil combination (Malarone® and generics) and doxycycline. It nevertheless remains an option when other treatments cannot be used.

Lariam® is contraindicated for the prevention of malaria in patients who have suffered or are suffering with psychiatric disorders (depression, generalised anxiety, suicidal thoughts, etc.) or who have a history of convulsions.

Since 2013, the European Medicines Agency (EMA) has implemented a plan to reduce the risks associated with mefloquine by providing a guide for prescribers and a patient alert card for people taking Lariam®, which should be kept with them during the duration of treatment.