Medical marijuana initiatives - Are they justified? How successful are they likely to be?

The principal constituent of cannabis, Delta(9)-tetrahydrocannabinol (THC), is moderately effective in treating nausea and vomiting, appetite loss, and acute and chronic pain. Oral THC (dronabinol) and the synthetic cannabinoid, nabilone, have been registered for medical use in the US and UK, but they have not been widely used because patients find it difficult to titrate doses of these drugs. Advocates for the medical use of cannabis argue that patients should be allowed to smoke cannabis to relieve these above-mentioned symptoms. Some US state governments have legislated to allow the medical prescription of cannabis, but the US federal government has tried to prevent patients from obtaining cannabis and threatened physicians who prescribe it with criminal prosecution or loss of their licence to practise. In the UK and Australia, committees of inquiry have recommended medical prescription (UK) and exemption from criminal prosecution (New South Wales, Australia), but governments have not accepted these recommendations. The Canadian government allows an exemption from criminal prosecution to patients with specified medical conditions. It has recently legislated to provide cannabis on medical prescription to registered patients, but this scheme so far has not been implemented. Some advocates argue that legalising cannabis is the only way to ensure that patients can use it for medical purposes. However, this would be contrary to international drug control treaties and is electorally unpopular. The best prospects for the medical use of cannabinoids lie in finding ways to deliver THC that do not involve smoking and in developing synthetic cannabinoids that produce therapeutic effects with a minimum of psychoactive effects. While awaiting these developments, patients with specified medical conditions could be given exemptions from criminal prosecution to grow cannabis for their own use, at their own risk.

Estimation of body fatness from body mass index and bioelectrical impedance: comparison of New Zealand European, Maori and Pacific Island children

Objective: To compare percentage body fat (%BF) for a given body mass index (BMI) among New Zealand European, Maori and Pacific Island children. To develop prediction equations based on bioimpedance measurements for the estimation of fat-free mass (FFM) appropriate to children in these three ethnic groups. Design: Cross-sectional study. Purposive sampling of schoolchildren aimed at recruiting three children of each sex and ethnicity for each year of age. Double cross-validation of FFM prediction equations developed by multiple regression. Setting: Local schools in Auckland. Subjects: Healthy European, Maori and Pacific Island children (n = 172, 83 M, 89 F, mean age 9.4 +/- 2.8(s. d.), range 5 - 14 y). Measurements: Height, weight, age, sex and ethnicity were recorded. FFM was derived from measurements of total body water by deuterium dilution and resistance and reactance were measured by bioimpedance analysis. Results: For fixed BMI, the Maori and Pacific Island girls averaged 3.7% lower % BF than European girls. For boys a similar relation was not found since BMI did not significantly influence % BF of European boys ( P = 0.18). Based on bioimpedance measurements a single prediction equation was developed for all children: FFM (kg) = 0.622 height (cm)(2)/ resistance +0.234 weight (kg)+1.166, R-2 = 0.96, s. e. e. = 2.44 kg. Ethnicity, age and sex were not significant predictors. Conclusions: A robust equation for estimation of FFM in New Zealand European, Maori and Pacific Island children in the 5 - 14 y age range that is more suitable than BMI for the determination of body fatness in field studies has been developed. Sponsorship: Maurice and Phyllis Paykel Trust, Auckland University of Technology Contestable Grants Fund and the Ministry of Health.