October 10, 2012

Benzodiazepine Use Increases Dementia Risk for Older Patients

Older patients who begin taking benzodiazepine for anxiety and insomnia are at far greater risk of developing dementia over the next 15 years than their cohorts who never took the drug, according to a new study.

In a caution to pharmacists and other health care providers, the authors note that, because of the 50% greater risk, "considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects, indiscriminate widespread use should be cautioned against.”

The study, published online recently by BMJ, the British Medical Journal, points out that the use of benzodiazepines by patients older than 65 is widespread in many countries, such as France, where 30% of that age group use it, Canada and Spain with 20%, and Australia with 15%.

Benzodiazepines are also commonly used in the U.S. and the United Kingdom but at somewhat lower rates, according to the study, which also notes that many patients take the drug for years despite guidelines suggested that its use be limited to a few weeks.
French researchers conducted a 20-year study of 1,063 men and women—average age 78—who were all free of dementia at the start. Out of the control group, 253 (23.8%) cases of dementia were confirmed, 30 in the 95 subjects who began taking benzodiazepine and 223 in nonusers.

The authors report that new initiation of the drug was associated with shorter dementia-free survival, with the chance of developing dementia at 4.8 per 100 person years in the exposed group compared to 3.2 per 100 person years in the nonexposed group. Factors potentially affecting dementia, such as age, gender, educational level, marital status, wine consumption, diabetes, high blood pressure, cognitive decline, and depressive symptoms were used to adjust the rates.

“Benzodiazepines remain useful for the treatment of acute anxiety states and transient insomnia,” the researchers maintain. “However, increasing evidence shows that their use may induce adverse outcomes, mainly in elderly people, such as serious falls and fall-related fractures. Our data add to the accumulating evidence that use of benzodiazepines is associated with increased risk of dementia, which, given the high and often chronic consumption of these drugs in many countries, would constitute a substantial public health concern.”

Health care providers should assess expected benefits, limit prescriptions to a few weeks, and avoid uncontrolled use, they advise. The authors also call for more research to "explore whether use of benzodiazepine in those under 65 is also associated with increased risk of dementia and that mechanisms need to be explored explaining the association."

U.S. Pharmacist Social Connect