A group of MPs in Britain have suggested that the controversial anti-malaria drug Larium should be banned from use in the military.
The Defence Select Committee launched an investigation into the drug's use after reports of severe side effects including depression and anxiety.
The Committee's report says that Lariam, which is also known as Mefloquine, should only be issued after a face-to-face assessment has been carried out and as a last resort - if the patient cannot take an alternative.
The troops should also be made aware of other anti-malarial drugs so they can choose which to take, they added.
The committee's findings could open the way for hundreds of civil cases from military personnel who have suffered the effects of the drug.
The committee's chairman, Dr Julian Lewis MP, said the British Ministry of Defence (MoD) had been irresponsible.
"It seems quite clear that not only is the MoD unable to follow the manufacturer's guidelines for prescribing the drug in all instances, but a number of troops discard their Lariam rather than risk its potentially dangerous side effects.
"It is our firm conclusion that there is neither the need, nor any justification for continuing to issue this medication to service personnel unless they can be individually assessed, in accordance with the manufacturers' requirements.
"And - most of the time - that is simply impossible, when a sudden, mass deployment of hundreds of troops is necessary."
The MoD responded by saying: "The vast majority of deployed personnel already receive alternatives to Lariam and, where it is used, we require it to be prescribed after an individual risk assessment.
"We have a duty to protect our personnel from malaria and we welcome the committee's conclusion that, in some cases, Lariam will be the most effective way of doing that."
The British military no longer gives Lariam to pilots or divers, but continues to issue it to soldiers and sailors.
Most NATO countries have stopped using Lariam but the once-a-week pill is issued to around 2,500 UK military personnel each year in accordance with Public Health guidelines in England.