Highlights of this issue

Opioid overdose

Figure. Photo by: The Image Bank

Drug overdose is a major cause of illness and death among illicit drug users. Fischer and colleagues interviewed 679 illicit opioid users from 5 Canadian cities and found that homelessness, noninjection use of hydromorphone in the previous 30 days and drug treatment in the previous 12 months were predictors of overdose. The authors rationalize that homelessness, a powerful social determinant of negative health status, is associated with poor health outcomes for drug users; that noninjection use of hydromorphone may have served as a proxy for the concurrent use of benzodiazepine by the subjects in their sample; and that treatments such as detoxification and methadone maintenance may lower users' drug tolerance and facilitate unfavourable drug interactions, thus increasing the risk of overdose.

See page 235

Obesity in preschool children

Obesity has become a major public health problem in both adults and children. Canning and colleagues have found that the problem may start in children as young as 3 years of age. In a province-wide study in Newfoundland and Labrador, the authors measured body mass indices of preschool children and found that 26% were overweight or obese.

See page 240

In a related commentary, Willms points out that although obesity is certainly a pressing problem, there may be problems in interpreting the data for children 3–5 years of age: conventional definitions of obesity and overweight may not accurately classify children who are of Asian descent or who are particularly short or tall.

See page 243

Vitamin B₁₂ deficiency

Figure. Photo by: Christine Kenney

Andrès and colleagues review the causes and clinical manifestations of vitamin B₁₂ (cobalamin) deficiency in elderly people. The complex metabolic pathway of the vitamin and the corresponding causes of deficiency are illustrated, and the authors remind us that the most common causes of deficiency are related to intestinal malabsorption and to the autoimmune destruction of gastric mucosa that characterizes pernicious anemia.

See page 251

In Synopsis

Figure. Photo by: WHO / P. Virot

What is the balance between access to new medications and patient safety? Lexchin discusses the tensions involved in reducing the time required for drug approval by Health Canada (page 229). Polio continues to spread in west and central Africa, prompting a warning from the World Health Organization (page 231). A clinical trial comparing saline and albumin for the resuscitation of critically ill patients finds similar outcomes (page 232). A man with an atypical pulmonary lesion is found to have a bacterial infection (page 233).