Rest easy if you're taking sleeping pills

‘SLEEPING PILLS linked to increased death risk” was typical of the headlines following the publication of research in BMJ Online last month. It certainly caused a stir, and to judge from readers’ responses, no little anxiety.

One correspondent said he was so alarmed by the research that he “decided to immediately cease further use and has been having a hard time since through lack of sleep . . . I noted criticism of the article in the BMJ from various sources on the website. However, if the results are even 50 per cent correct, there appears to be a possible tripling of the chances of death within my age group (55-65) and substantially increased risk of cancer compared to those not taking such drugs.”

There are many people in this country who rely on taking a “sleeper” to achieve something that approximates to a good night’s sleep. Most hypnotic drugs are benzodiazepines and so are considered to cause addiction within as little as 14 days’ use.

Prescribing guidelines now advise against their use for longer than two weeks at a time; however, many were prescribed long-term treatment years before these guidelines were introduced and have experienced immense difficulty attempting to wean themselves off the medication. So there is a cohort of older people in particular who require regular prescriptions for sleeping tablets because they are now “hooked” on them.

What did the research show? The US authors tracked the survival of more than 10,500 people with a range of underlying conditions, who were prescribed sleeping pills for an average of 2.5 years between 2002 and 2007. They then compared this group’s survival with a similar group who had not been taking sleeping pills over the same period and found some sleeping pills were associated with a fourfold increased risk of death. And the authors claim to have found a greater prevalence of cancer among those taking the pills.

The most important point to make about this research is that it did not find that hypnotic drugs cause premature death. At best, it found an association and even at that, the research is open to some criticism.

Because people with insomnia who didn’t take sleeping tablets were not included in the control group, it could be argued that it is the insomnia and not hypnotics that is contributing to excess deaths. People with a sleep disorder are more likely to have an underlying disease that contributes to higher mortality. If the insomnia was due to depression, might this increase the risk of suicide among those taking hypnotic drugs? And sedative drugs make people drowsy and therefore more at risk of falls.

But probably the biggest hole in the research was the failure to examine the actual causes of death in detail. This would have enabled some logical cause-and-effect theories to be explored.

And the researchers are on especially rocky ground when it comes to linking sleeping tablet use with a greater risk of developing cancer. For starters, most cancers are slow growing, so the 2.5-year follow-up period of this study is not long enough to draw any conclusions. As a correspondent to the journal noted: “We are sceptical as to whether the incident cancers are indeed related to hypnotic use, as it is plausible that hypnotic users had an undiagnosed cancer before hypnotic prescription, and developed cancer independently of hypnotic use.”

The best that can be said about the research is that it raises questions that require more detailed studies to answer. Doctors no longer prescribe long-term sleeping tablets for patients presenting with insomnia for the first time, so the authors’ conclusions are irrelevant to those people given the drugs for the short-term relief of trauma.

For patients who have been taking hypnotics for years, the study is not robust enough to warrant going “cold turkey”.

By all means, discuss the issue with your GP at your next routine consultation, but there is no reason to abruptly stop taking the tablets.