Highlights

Seasonal variation of leg cramps

Nocturnal leg cramps display striking seasonal variability, with incidence highest in summer and lowest in winter. This time-series analysis used population health services data from British Columbia for new quinine prescriptions dispensed to 31 339 patients over six years, as well as Internet search data from Google Trends for the United States and Australia over eight years, as surrogates for the occurrence of leg cramps. Why this common musculoskeletal disorder should vary in this manner deserves further investigation, say the authors. See Research, page 248

Quinine sulfate is widely used off label to treat nocturnal leg cramps in Canada. Although modestly effective for this indication, the drug has many potential moderate and severe adverse effects. Other drugs and nonpharmacologic measures are also effective. A time-limited trial of quinine could be an option for fully informed patients experiencing frequent, severe cramps that disrupt their sleep only if other potential causes have been ruled out and less harmful approaches tried, says Hogan. See Commentary, page 237

Quality indicators of pharmacotherapy

Polypharmacy, potentially inappropriate medications and anticholinergic medications are each associated with increased risk of admission to hospital; two of these are also associated with fracture-specific admission risk. These findings from a large cohort of older people from The Taiwanese National Health Insurance Database support results from smaller studies and afford opportunities for risk reduction. See Research, page E130

Antibiotics, spironolactone and death

Among older patients taking spironolactone, those prescribed trimethoprim–sulfamethoxazole had twice the odds of sudden death compared with patients prescribed amoxicillin. Co-prescription of ciprofloxacin and spironolactone was also associated with an increased risk of sudden death. This nested case–control study used population health services data from Ontario to identify 328 patients aged 66 or older taking spironolactone who experienced sudden death within 14 days after receiving a co-prescription for trimethoprim–sulfamethoxazole or another study antibiotic and 1171 matched controls. When appropriate, clinicians should consider alternative antibiotics for patients receiving spironolactone, say the authors. See Research, page E138

Use of intravenous immunoglobulin

Intravenous immunoglobulin exerts anti-inflammatory and immune-modulating effects through broad and possibly synergistic mechanisms. It is useful for some conditions. Gilardin and colleagues discuss its utility in this clinical review article. See Review, page 257

Diabetes in long-term care settings

An 80-year-old frail woman living in a long-term care residence is seen for a periodic health examination by her family physician. She has type 2 diabetes. How does her frailty affect targets for glycemic control? Does she require medication? How worried should her physician be about hypoglycemia? Tessier and Meneilly address these and other questions in this look at managing diabetes in frail older patients. See Decisions, page 269

Human myiasis in Canada

Travel to exotic locations is not required to acquire human myiasis infestation. MacFadden and colleagues report two cases — one acquired locally and the other acquired through travel — of this infestation by fly larvae. See Cases, page 272

Dyspepsia

The authors of this Choosing Wisely Canada article highlight five important points in the diagnosis and management of dyspepsia. These range from who should have endoscopy to testing for Helicobacter pylori infection. See Five things to know about …, page 276