The Quinoline Era
How two military antimalarial drugs were administered to thousands of Australian soldiers — and what happened when the trials ended.
Between the late 1990s and the early 2000s, the Australian Defence Force administered mefloquine and tafenoquine to thousands of soldiers deployed to Bougainville and East Timor. Many of those soldiers were participating, knowingly or not, in formal clinical drug trials. The era left a neurological legacy that is still unfolding today.
A Chronology
Origins: The US Army Drug Programme
The Walter Reed Army Institute of Research (WRAIR) develops mefloquine as part of a military programme targeting chloroquine-resistant malaria in South-East Asian conflict zones. The drug is designed for soldiers, tested on soldiers, and ultimately deployed to soldiers worldwide.
Mefloquine Enters the Market
Commercialised by F. Hoffmann-La Roche, mefloquine is released following limited civilian clinical testing. It becomes the first-line antimalarial prophylactic for US and UK military forces, and the second-line drug for the ADF. The first reported case of mefloquine encephalopathy emerges before the decade is out.
Tafenoquine Trials Begin: Bougainville
The ADF’s Army Malaria Institute (AMI) begins formal tafenoquine trials on personnel deployed to Bougainville. Subjects receive doses of up to 1,200 mg over three days. Tafenoquine is not yet registered for civilian use anywhere in the world.
East Timor: The Peak of the Trial Period
ADF deployments to East Timor become the central site of both mefloquine and tafenoquine administration. An estimated 1,319 personnel are enrolled in mefloquine trials. Loading doses of mefloquine reach up to 1,500 mg per week — six times the approved prophylactic dose.
Fort Bragg: A Warning the World Ignored
Within six weeks at Fort Bragg, North Carolina, four US soldiers returning from Afghanistan kill their wives. Three subsequently die by suicide. The US Army and CDC investigate but attribute the cluster to PTSD and reintegration stress. Mefloquine’s pharmaceutical role is not systematically examined.
WRAIR Finding: Tafenoquine More Neurotoxic Than Mefloquine
Scientists at the Walter Reed Army Institute of Research publish in-vitro findings establishing tafenoquine as the only antimalarial drug more neurotoxic than mefloquine. No longitudinal follow-up health studies are initiated for the 1,540 ADF tafenoquine trial subjects. None have been conducted to this day.
The FDA Black Box Warning
The US Food and Drug Administration issues its strongest possible safety warning for mefloquine, stating explicitly that neuropsychiatric adverse reactions — including psychosis, paranoia, hallucinations, depression, and suicidal ideation — may persist for months or years after the drug is stopped, and may in some cases become permanent. Australia does not initiate a review of the affected ADF cohort.
The RMA Determination: A Door Closed
The Repatriation Medical Authority determines there is insufficient evidence to link quinoline exposure to acquired brain injury — a determination made without examining veterans’ medical records and without neurotoxicology expertise. The decision forecloses the main pathway by which veterans could access appropriate care and compensation.
Senate Inquiry Submissions
Major Stuart McCarthy (QVFA) and Professor Jane Quinn submit detailed evidence to the Senate Foreign Affairs, Defence and Trade References Committee documenting the scale, severity, and institutional neglect of quinoline-related harm in the ADF.
The Royal Commission: A Partial Reckoning
The Royal Commission into Defence and Veteran Suicide tables its Final Report in September 2024. Volume 4, Chapter 22 addresses mefloquine and tafenoquine directly, recommending a dedicated brain injury program for affected veterans. In December 2024, the Australian Government accepts 104 of 122 recommendations. Spouses and family members remain outside the scope of any proposed program.
The Drugs
Two quinoline compounds sit at the centre of this era. Both were developed by the US military. Both are now recognised by major regulatory agencies as carrying substantial neuropsychiatric risk. Both were administered to Australian soldiers — in clinical trial conditions — without the informed consent or follow-up care those conditions require.
Mefloquine
A synthetic quinoline antimalarial commercialised by F. Hoffmann-La Roche in the 1980s. Used as a weekly prophylactic, the standard approved dose is 250 mg per week. ADF trial subjects received loading doses of up to 1,500 mg per week.
Formally recognised adverse effects include:
- Very common (>10% of users): abnormal dreams, insomnia
- Common (1–10%): anxiety, depression, visual impairment, vertigo
- Uncommon: hallucinations, aggression, psychosis, paranoia, delusional disorder, depersonalisation, mania, suicidal ideation, memory impairment, long-term vestibular disorders
“Neuropsychiatric adverse reactions may persist after mefloquine has been discontinued. In some cases, symptoms have been reported to continue for months or years after mefloquine has been stopped.”
Tafenoquine
A newer quinoline compound also developed by WRAIR, trialled on over 1,540 ADF subjects before receiving civilian registration anywhere in the world. In 2009, WRAIR’s own scientists established it as the only antimalarial drug more neurotoxic than mefloquine.
Despite this finding, no longitudinal follow-up health studies have ever been conducted on the original ADF trial cohort. The TGA’s adverse event database (DAEN) holds ADF trial reports including completed suicide, suicidal ideation, brain injury, and chronic psychiatric disorders.
Individuals with poor or intermediate CYP2D6 enzyme function — estimated at 12–23% of Caucasian populations — may be unable to clear quinoline compounds from the brain before toxic concentrations accumulate. Every ADF tafenoquine trial subject who voluntarily underwent CYP2D6 testing returned a poor or intermediate metaboliser result.
What the Era Left Behind
When the deployments ended and the trials concluded, the Army Malaria Institute closed its files. The soldiers went home. No systematic health follow-up was initiated. No outreach program was established. No family support framework was created.
What the quinoline era left behind was thousands of men carrying neurological injuries that had not been diagnosed, would not be treated, and would not be recognised — living in homes with partners and children who had no way of understanding what had changed, or why.
The QVFA submission to the Australian Senate documents the downstream consequences: family breakdown, unemployment, homelessness, incarceration, and suicide. Coronial inquests into veteran suicides have been completed without coroners receiving the relevant AMI trial records.
The absence of documented case series linking quinoline toxicity to domestic harm is not evidence that the harm is small. It is evidence that no institution has ever looked. The cases exist. The framework for seeing them does not.