By Bianca Nogrady
Opioids for chronic noncancer pain may improve sleep quality, but this could come with the cost of excessive daytime sleepiness, increased sleep-disordered breathing and quicker onset of REM sleep, research suggests.
A systematic review and meta analysis, published in Sleep Medicine Reviews, examined data from 18 studies – 12 of which were randomised controlled trials – and 3746 patients with chronic noncancer pain.
The most common therapies used for pain management were oxycodone and transdermal fentanyl.
The analysis found that while people with chronic noncancer pain reported calmer sleep with less body and leg movements, fewer night time awakenings and a better quality of sleep, they also reported increased severity of sleep-disordered breathing. There was also the suggestion of an increase in excessive daytime sleepiness.
The authors stressed that while the balance of evidence suggested sleep improvements with opioid therapy, the magnitude of improvements was small and the ‘meaningfulness’ of the improvements was not addressed by many of the included studies.
‘A high level of caution is required for the interpretation of the results, given the potential publication bias towards positive findings with studies of greater precision producing smaller or no effect,’ they wrote.
Commenting on the findings, Dr Gabrielle Campbell, Senior Research Fellow at the National Drug and Alcohol Research Centre at UNSW Sydney, said the challenge with meta analysis of this issue was the heterogeneity and complexity of the patient population.
‘Chronic pain is the combination of biological, psychological and social factors, so for some people where the chronic pain is mainly biological, medical interventions may help, but if there are other psychological and social factors present, medication is not going to be enough,’ Dr Campbell told Pain Management Today.
She said people with chronic pain also tend to have a range of comorbidities, such as sleep apnoea, that could affect how opioids influence their sleep quality, and that the impact of opioids on sleep quality had to be examined at the level of the individual patient.
Sleep Med Rev 2019; 45: 105-126.