In a questionnaire-based study, Richard Frith from Auckland Hospital, New Zealand, and colleagues surveyed 1782 students in their first year at the University of Auckland. Just under 60% of students who responded were aware of the use of nitrous oxide for recreational use; 12% of students reported that they had used it for this purpose, and 3% were regular users (once a month or more).
Nitrous oxide capsules are used in domestic appliances (such as processors to aerate cream) and are therefore readily available from hardware stores. Regular inhalers of the gas refer to this behaviour as 'nanging' - a phrase coined to represent the repetitive sound distortions induced by use of this drug. Nitrous oxide blocks the action of vitamin B12 which accounted for the spinal damage reported in the Lancet case report last year.
Richard Frith comments: "Our results show a previously unrecognised high prevalence of recreational nitrous oxide use in first-year university students at Auckland University. Generally, few students were aware of the potential acute or chronic ill effects from use of this substance. Potential harm from nitrous oxide is not included routinely in drug education programmes. Moreover, with an increasing proportion of vegetarianism, many young people have a higher risk of vitamin B12 deficiency, further increasing their risk of subacute combined degeneration of the spinal cord. The high prevalence of such use should alert physicians to the possibility of nitrous-oxide use in young people who present with subacute myelopathy, but are otherwise healthy."
Contact: Dr Richard Frith, Department of Neurology, Auckland Hospital, Auckland, New Zealand;
T) 64-9379-7440;
F)64-9307-8912;
E) richardf@adhb.govt.nz
Journal
The Lancet