Question to the Ministry of Defence:

To ask the Secretary of State for Defence, if he will assess the effect of the use of Lariam on the quality of performance of military personnel on operations.

Mefloquine (commercially known as Lariam) is an effective anti-malarial that is used by many militaries to protect their personnel while on operations. There is no defined caveat from any advisory body in the world that suggests the use of mefloquine should be restricted in military personnel or people who handle weapons.

Although there is no evidence that mefloquine impairs function, in accordance with guidance from Public Health England, the Civil Aviation Authority and others, the drug is not used by military aircrew. Mefloquine is also not used by divers, as its side effects could potentially be confused with decompression or narcosis events.

In October 2015, the results were published of a Ministry of Defence questionnaire-based study of anti-malarial use by UK Service personnel training in Kenya during 2012 and 2013. This found that significantly more doxycycline than mefloquine users reported that one or more adverse effects had interfered with their ability to do their job.