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Mefloquine FAQs

What is mefloquine?

Mefloquine is an anti-malarial medication that can be used for both prevention and treatment of malaria. Up until September 2018, it was one of only three medications approved by the Australian Therapeutic Goods Administration (TGA) for malaria prevention and is currently used around the world. In the ADF mefloquine it is only used when another antimalarial medication is not appropriate.

Is mefloquine safe?

Mefloquine was first registered with the Therapeutic Goods Administration in 1988 for the treatment of malaria and in 1993 for malaria prophylaxis. Since then there have been over 35 million prescriptions of mefloquine world-wide. The TGA is responsible for monitoring/evaluating the safety and efficacy of therapeutic products and manages any risks associated with individual products. When registering mefloquine for use in Australia, the TGA assessed that it was a safe and effective medication suitable for use as malaria prophylaxis.

However all medicines have some side effects and mefloquine is not suitable for everyone. Mefloquine has known side effects and precautions need to be taken in individuals with particular health conditions, including any mental health condition or seizure disorder. In Defence mefloquine is only ever prescribed by a qualified medical practitioner in accordance with both the TGA approved product information and our own health policy. Defence health policy incorporates all TGA recommendations and builds on that advice to ensure that the ADF’s medical protocols remain consistent with best practice.

What are the side effects of mefloquine?

For most people taking mefloquine side effects are minor and the medication is generally well tolerated. When taken for malaria prevention, the predominant side effects are neuropsychiatric – sleep problems, vivid dreams, anxiety, and depressive symptoms. Trouble sleeping and vivid dreams are the most common of these, occurring in around 13% of people.

Uncommonly, people taking mefloquine can experience agitation, restlessness, mood swings, panic attacks, confusion, hallucinations, aggression, psychosis and suicidal ideation. These symptoms occur in less than 1% of people taking mefloquine.

Other neurological symptoms, such as dizziness and headache are relatively common, occurring in up to 10% of people. Uncommonly (less than 1%), balance problems and seizures can occur. People who have, or have had, any mental health condition or seizure disorder should not take mefloquine.

How long do side effects last?

Usually, if someone experiences side effects from mefloquine, it happens soon after starting it. That is one of the reasons it is started before deployment so that this can be monitored and the medication stopped if necessary.

Side effects usually go away within days or weeks after stopping mefloquine. In rare cases, side-effects may persist for months or longer. In some people, the effect may be permanent.

Because mefloquine is long acting, it is possible that some people may first have side effects in the weeks after stopping mefloquine. New side effects have not been known to occur once mefloquine has completely left the body.

Does mefloquine interact with other medications?

Like all drugs mefloquine can interact with other medications. Mefloquine can affect the action of some antifungals, anticonvulsants, heart medications and other antimalarials. It is important that the prescribing doctor is made aware of any other medications the person is taking before prescribing mefloquine.

Why does the ADF use mefloquine if it can have such serious side effects?

Malaria is a deadly disease and anti-malarial medications are a crucial component of malaria prevention in deployed troops as it is not possible to completely avoid mosquito bites. For individuals who cannot take other anti-malarial medications, mefloquine provides a necessary alternative.

Prescribing information for doctors and consumer medicine information for patients explain the possible side effects and advise who should not take mefloquine. ADF members are individually assessed by medical personnel before they are prescribed mefloquine and are briefed about what signs and symptoms to watch for. They are also advised to report any symptoms to a health practitioner immediately. Side effects to a medication usually occur early. By starting mefloquine before deployment, any side effects that develop can be seen and managed.

Both the TGA and the ADF monitor adverse reactions to medications through their adverse event reporting systems.  The TGA requires that the manufacturer revise the product information and the consumer medicine information if new information becomes available.

Does mefloquine cause post traumatic stress disorder (PTSD)?

There is no evidence that mefloquine causes or triggers post traumatic stress disorder (PTSD). In some cases neuropsychiatric side-effects from mefloquine may have some similarity to those of an acute stress reaction; however a diagnosis of PTSD requires the exclusion of medications as a cause of symptoms.

The vast majority of ADF members have never been prescribed mefloquine. Centralised medicines dispensing information has only been available in the ADF since 2000 and records show that between July 2000 and end 2017, approximately 1,982 ADF personnel have been prescribed mefloquine. Most of these prescriptions were as part of the AMI studies in Timor Leste from 2000-2002 (a total of 1,319 soldiers).

On average, less than 25 ADF members will be prescribed mefloquine each year. The following table shows how many ADF members were prescribed mefloquine from 2010-2016.

Number of ADF members prescribed mefloquine 2010-2017

Year Number of ADF members
2010 25
2011 26
2012 13
2013 20
2014 35
2015 15
2016 5
2017 2

Is taking mefloquine a precondition for overseas deployment?

Deployment to any area of operations involves appropriate force health protection, to minimise the chance of injury or illness.  This will often include particular vaccines or medications.  Deployment to malarious areas involves ADF members taking anti-malarial medication.  For some individuals mefloquine will be the most suitable medication. However Defence health policy requires ADF members be properly informed of the potential side-effects of mefloquine and the drug may only be prescribed after the member has consented.

How commonly is mefloquine used in Australia and around the world?

Mefloquine is one of four anti-malarial medications approved by the TGA for travel to malarious areas in our region. It is used around the world for both prevention and treatment of malaria and is included in anti-malarial guidelines published by:

The World Health Organization International Travel and Health
The US Centers for Disease Control and Prevention
The Public Health Agency of Canada
The United Kingdom Advisory Committee on Malaria Prevention

Can ADF personnel refuse to take mefloquine?

Yes, ADF personnel may refuse to take mefloquine. However, if they are deploying to a malarious area, then they will be required to take an anti-malarial medication to protect them against malaria. If mefloquine is the only suitable medication, and they do not want to take it, they would not be able to deploy.

Is mefloquine used by civilians?

Yes, mefloquine is prescribed for civilians travelling overseas to malarious areas. It is popular as it is taken as a once weekly dose rather than daily.

The following table shows how many prescriptions were written each year in Australia from 2010-2017.

Estimated Australian Civilian Prescription Data

Anti-malarial 2010 2011 2012 2013 2014 2015 2016 2017
Mefloquine 14,149 16,512 13,674 14,030 13,770 12,713 11,457 TBA
(Source: Australian statistics on medicines/Roche Products Pty Limited)

What is the ADF response to reports the US Food and Drug Administration (FDA) has issued warnings regarding the potential neurological and psychiatric side effects associated with the use of mefloquine?

Both the TGA in Australia and the FDA in the United States routinely issue warnings on medicines, as detailed in the product information for prescribers and the consumer medicine information for patients.

In 2013, the FDA updated its advice regarding neurological side effects of mefloquine. The FDA added a warning label to the medication stating that neurological side effects may persist or become permanent in some people. These side effects include dizziness, loss of balance or ringing in the ears. The possibility of long term dizziness, balance problems and ringing in the ears was already recognised in product information published by the TGA.

Has the US military banned mefloquine?

The US military retains mefloquine as an option for malaria prevention and continues to use it when it is the only suitable anti-malarial for a particular individual. They describe it as ‘drug of last resort’ while the ADF uses the term ‘third line agent’. In practice however this means the same thing: mefloquine is only to be prescribed when there is no other suitable anti-malarial. Elements of the US Special Forces suspended the use of mefloquine in 2013 in response to the updated FDA advice; however have since resumed using mefloquine as a ‘drug of last resort’.

If mefloquine is safe, why did the UK Parliament investigate it? Why won’t Australia do the same?

The UK House of Commons Defence Committee recently completed an inquiry into the use of mefloquine by the British armed forces. The subsequent report recommended that any future prescribing of mefloquine to UK military personnel be restricted:

  • Only to those who are unable to tolerate any of the available alternatives;
  • Only after a face-to-face Individual Risk Assessment has been conducted; and
  • Only after the patient has been made aware of the alternatives and has been given the choice between Lariam and another suitable anti-malarial drug.

These recommendations are very much in line with the existing ADF policy, one that the ADF has had in relation to mefloquine for some years. In the ADF mefloquine is only prescribed if other medications are unsuitable. Further to this, our health policy requires ADF members be properly informed of the potential side-effects of mefloquine and the drug may only be prescribed by a qualified medical practitioner after the member has provided their informed consent.

The report also recommended that the UK Ministry of Defence create a single point of contact for all current and former personnel who have concerns about their use of mefloquine. In Australia this has already been done, with the development of this website and the creation of a specific email address for individuals to contact us directly about their concerns (

How many ADF personnel have suffered lasting side-effects?

Most ADF members who have taken mefloquine did so as part of the AMI studies in Timor Leste from 2000-2002 (a total of 1,319 soldiers). The outcomes of the trials were published in peer reviewed medical journals. There were no permanent neurological adverse events identified during the trials.

Is the ADF aware of claims that mefloquine can have severe and fatal side effects?

Defence maintains a list of ADF members known or suspected of having died by suicide whilst serving. This list has been cross checked against ADF prescribing data on mefloquine since July 2000. As at 30 April 2019, two of the individuals on that list had been prescribed mefloquine by Defence more than 15 years prior to their deaths.

How can I find out if I was prescribed mefloquine while serving in the ADF?

Mefloquine is an anti-malarial that is taken once a week. If an ADF member was prescribed a weekly anti-malarial then it was most likely mefloquine. If the medication was taken daily then it was definitely not mefloquine.

Centralised prescribing information is available from 2000, prior to that all records were paper based or maintained on local systems.

Current ADF members can request this information from their supporting Defence health facility (if the prescription occurred after 2000).

Ex-serving members who are concerned about the anti-malaria medication they may have taken in the past may request a copy of their health records by submitting a request to the Defence Archives Centre at More information is available from Defence Service Records site.

What support is available for current and former members who believe they have been adversely affected by mefloquine?

If any ADF member, past or present, is concerned that they might be suffering side-effects from the use of mefloquine they should present to their usual medical practitioner for assessment and treatment as appropriate. 

With medications like mefloquine, most side-effects commence soon after commencing the medication and resolve fully soon after ceasing the medication.  Rarely, side effects may first appear shortly after ceasing the medication.  Symptoms that first develop months to years after ceasing an anti-malarial medication are most unlikely to be related to past anti-malarial use and much more likely to be due to other causes. This is because once the medication has completely left the body, it has no effect.

Any ADF member who feels that their health problems may be related to any aspect of their military service is encouraged to submit a claim to the Department of Veterans’ Affairs.

Claims should be made directly to DVA and more information is on the DVA website. A number of ex-service organisations provide advocate services to assist members with the submission of claims for liability to DVA.

DVA has also set up a dedicated phone line 1800 MEFLOQUINE (1800 633 567) for veterans with enquiries, including support available.

Where can I get more information?

Recent publications regarding mefloquine are available in the additional resources section of this site.