The role of benzodiazepines in elderly suicides

In Sweden, suicides by drug poisoning have decreased in the population at large during the past two decades. However, drug poisoning suicides increased among the elderly during this period. Suicides by benzodiazepine poisoning increased in this age group despite a reduction in prescription sales of these drugs. This study aims therefore to determine the role of benzodiazepines in suicide late in life.

Information concerning all definite suicides and deaths due to "undetermined" causes recorded among Swedish citizens aged 65 and above during 1992 - 96 was obtained from the Cause-of-Death Register. Death certificates were scrutinized to determine the type of drug employed in drug-related suicides. Results of the post mortem screening for drugs and alcohol were then examined.

A benzodiazepine was implicated in 216/548 (39%) of the drug poisoning suicides recorded among the elderly. Death certificates revealed that a benzodiazepine was the sole agent in 72% of these cases. Flunitrazepam or nitrazepam were implicated in 90% of the single benzodiazepine suicides. In addition to the suicides classified as drug poisonings, 82 cases were found in which a drug may have contributed to the cause of death. Benzodiazepines predominated. The terminal cause of death was drowning, often in the victim's own bathtub, in three-quarters of these cases. The annual fatality ratios for the newer benzodiazepine-like hypnotics zopiclone and zolpidem appear to be on the rise.

Benzodiazepines, especially the hypnotics flunitrazepam and nitrazepam, are common in drug poisoning suicides in the elderly and should be prescribed with caution for this age group.