Pain, Sleep, and Opioids

Of all the problems that accompany chronic pain, among the most common is difficulty with sleep. Even though patients with chronic pain often report that lying down is the most comfortable position for them, this doesn’t necessarily translate into good sleep.

In trying to address sleep problems occurring in patients with chronic pain, we face a number of challenges. The first is that we still lack clear guidelines on how to best address them. Practitioners will find very little specific guidance in the literature and usually must depend upon the more general guidelines on managing sleep disorders.

Another challenge is that medications commonly used to treat pain can have a disruptive effect on sleep. This can be overlooked because many healthcare providers and probably most laypeople tend to view sedation as being synonymous with improving sleep. However, this is far from true.

When considering what’s good for sleep, it is important to remember that sleep is not a uniform activity throughout the course of the night, but instead, a series of cycles involving different levels of wakefulness. Just because a medication may put one to sleep doesn’t mean it will provide restful sleep if it disrupts the normal sleep cycles.

Opioids are an excellent example of a class of medication that have sedative effects but are not especially beneficial for sleep. Although we have known this for years, a new study once again highlights this.¹

The study evaluated patients at a US Department of Veterans Affairs medical center and compared the sleep of those with chronic pain who were taking opioids with those who had chronic pain but were not taking opioids, as well as with a control group whose members didn’t have chronic pain and weren’t taking opioids. Sixty-eight percent of the opioid users had been taking the medications every day for 3 months or longer.

Those taking opioids were found to have more impaired sleep, including worse subjective sleep quality, sleep latency, and sleep disturbance, compared with the other two groups. They were found to be more likely to be diagnosed with sleep apnea and taking other medications to aid sleep. They also reported having more severe pain and depression than those with chronic pain who weren’t using these medications.

The results of this study reinforce what we already know about sleep, pain, and medications. A study I did a number of years ago found that patients with chronic pain who were taking both opioids and benzodiazepines had worse sleep than those taking one or the other, who, in turn, had worse sleep than those with chronic pain who were taking neither.²

The current study is subject to the same limitation as my study. It is possible that the patients who were taking more medications had more pain and this, rather than the medications, resulted in poorer sleep. This is certainly a plausible explanation for some patients. However, there is other research that suggests that the medications may be playing a more significant role than is commonly thought.

Although both opioids and benzodiazepines cause sedation, they can also disrupt the normal sleep cycles, especially REM and stages 3 and 4 of non-REM sleep. What makes this disruption even worse is that it has been found that these are the same stages of sleep already most likely to be disrupted in people with acute or chronic pain.

It is also important to remember that though pain can affect sleep, the reverse can also be true. Multiple studies have demonstrated that simply by disrupting the normal sleep cycles, widespread pain similar to that reported by patients with fibromyalgia can be precipitated in asymptomatic, healthy volunteers.

Thus, the very medications we may be prescribing to aid in sleep can not only be having the opposite effect and making it worse, but also, as a result of this, can actually be exacerbating the pain.

Unfortunately, the current study did not seek to identify the types of sleep medications the participants were taking. It would be useful to know if this finding applies to all sleep medications or only those in certain classes such as benzodiazepines.

The study’s finding of the increased frequency of sleep apnea in patients taking opioids is an interesting one and is especially important, as this disorder is potentially life-threatening. Based on this result, the authors recommend that patients prescribed opioids on a long-term basis be screened for this problem.

I agree with this recommendation. Certainly all patients for whom opioids may be needed on an extended basis should be asked about a history of sleep apnea and of any previous problems with sleep. For those with other possible symptoms of this disorder, such as loud snoring, or those who have risk factors, such as being overweight, it may be worthwhile to obtain a consultation with a sleep expert. Obviously, for those at risk or for those who already suffer from sleep apnea, it would be important to consider either factor when making the decision of whether to prescribe opioids on an ongoing basis.

The increasing use of extended-release/long-acting (ER/LA) opioids makes it especially important that we watch for sleep apnea in patients. Opioids can cause respiratory depression the leading cause of death from opioid overdoses), and since the ER/LA opioids maintain a consistent blood level of medication throughout the night, patients with sleep apnea are at risk for serious problems.

How do you manage sleep issues with your patient with chronic pain? 

References:

1. Morasco BJ, O’Hearn D, Turk DC, Dobscha SK. Associations between prescription opioid use and sleep impairment among veterans with chronic pain.Pain Med. 2014 Jun 14. [Epub ahead of print]

2. King SA, Strain JJ. Benzodiazepine use by chronic pain patients. Clin J Pain. 1990;6:143-147.