Benzodiazepines and Chronic Pain

Several months ago, I wrote about studies examining the use of benzodiazepines by chronic pain patients (CPP). The results of the studies indicated that benzodiazepines are frequently prescribed to this population contrary to what are considered current best practices.

There are now more recently published studies that also support this view and which add to the reasons I gave in my previous column as to why the presence of chronic pain and the prescription of opioids are usually contraindications for prescribing benzodiazepines.

The pharmacy benefit company Express Scripts examined 6.8 million patients who filled at least one prescription for an opioid from 2009 through 2013.¹ They found that of the patients taking opioids for more than 30 days (suggesting the presence of chronic pain), almost 30% were prescribed a benzodiazepine during the same month. The apparent overprescription of benzodiazepines may be at least partly due to the poor coordination of care, which is indicated by the fact that a majority of patients were prescribed the two drugs by two or more physicians.

An Australian study of medication usage by 224 CPP found that 80% were taking opioids and 30% were taking benzodiazepines.² Using a measure to assess the potential detrimental effect of medications, it found that patients taking these two classes were at highest risk for detrimental effect.  

Another Australian study examined benzodiazepine use among 1,220 CPP and the effect it had on their physical and mental health.³ One-third of the subjects reported using benzodiazepines within the month prior to entering the study, and 17% reported using at least one of these drugs daily.

The most important conclusion from this study is its finding that benzodiazepine use was associated with many other problems. Compared with non-users, benzodiazepine users reported greater levels of pain and lower feelings of self-efficacy. They were more likely to be taking higher doses of opioids, as well as antidepressants or antipsychotics and to have a history of a diagnosed mental disorder. They were also more likely to report use of illicit drugs and an alcohol use disorder, in addition to being more likely to use emergency healthcare services at a greater rate.  

These findings further support the view that benzodiazepine use should generally be avoided by CPP. Further, the findings certainly fit with our knowledge that benzodiazepines can interfere with the analgesic effects of opioids and can cause hyperalgesia.

The likelihood of illicit drug use and alcohol use disorders might indicate that the benzodiazepines are being used to treat these problems, but it is also possible that their usage reflects an additional substance use disorder.

Overall, these three studies further demonstrate that benzodiazepines continue to be erroneously prescribed to many CPP and that this has many potential negative effects on their health. The fact that physicians can continue to frequently prescribe them to these patients despite all the evidence that this should not be done is disturbing.

Although it didn’t look specifically at benzodiazepine use among CPP, another new study using a different prescription database found that benzodiazepines are overprescribed in the United States, especially to older patients for whom their use is generally contraindicated, and that they are often being prescribed for far longer periods than is recommended or considered to be safe.⁴

Since we assume that most physicians are trying to do their best for their patients, what explains so many of them doing something potentially injurious?

I could be that, despite the common knowledge that benzodiazepines can be abused and cause addiction, physicians are pressured to prescribe, against their better judgment, by aggressive patients who in fact are protecting their source of supply.

However, I think the main reason is simply physician ignorance about how little benefit these drugs have for most patients, including those with chronic pain, and the potential harm the drugs can cause. That the study on benzodiazepine use in the U.S. found that psychiatrists, who receive the most training in the therapeutic use of benzodiazepines, are the most likely of all physicians to prescribe them appropriately, indicates just how important education is.⁴

References:

1. The Express Scripts Lab. A Nation in Pain. Available at: http://lab.express-scripts.com/publications/a-nation-in-pain. Accessed December 23, 2014.

2. Giummarra MJ, Gibson SJ, Allen AR, et al. Polypharmacy and chronic pain: harm exposure is not all about the opioids. Pain Med. 2014 Oct 3. [Epub ahead of print] http://www.ncbi.nlm.nih.gov/pubmed/25280054

3. Nielsen S, Lintzeris N, Bruno R, et al. Benzodiazepine use among chronic pain patients prescribed opioids: associations with pain, physical and mental health, and health service utilization. Pain Med. 2014 Oct 3. [Epub ahead of print] http://www.ncbi.nlm.nih.gov/pubmed/25279706

4. Olfson M, King M, Schoenbaum M. Benzodiazepine use in the United States. JAMA Psychiatry. 2014 Dec 17. [Epub ahead of print] http://archpsyc.jamanetwork.com/article.aspx?articleid=2019955