Oxycodone for pain in fibromyalgia in adults

Bottom line

There is no good evidence to support or refute the suggestion that oxycodone, alone or in combination with naloxone, reduces pain in fibromyalgia.

Background

Fibromyalgia is a complex disorder characterised by widespread pain, fatigue, poor sleep, low mood, and other bodily symptoms. Common pain-relieving medicines such as paracetamol and ibuprofen are not usually considered effective. Opioid painkillers are commonly used to treat fibromyalgia, but there is uncertainty over how good they are.

Opioid painkillers are drugs like morphine. Morphine is derived from plants, but many opioids are also made by chemical synthesis rather than being extracted from plants. Oxycodone is a semi-synthetic opioid, manufactured from the opioid alkaloid thebaine, and is widely available.

This review replaces part of a review originally published in 2014, which examined how well oxycodone worked in pain in fibromyalgia and some other medical conditions. In this review, we examined only pain in fibromyalgia. In the previous review, we did not find any evidence that oxycodone is, or is not, of value in treating pain in fibromyalgia.

Study characteristics

In July 2016, we searched for clinical trials where oxycodone, either alone or in a fixed-dose combination with naloxone, was used to treat pain due to fibromyalgia in adults. We did not find any studies that met the requirements for this review.

Key results

There was no information from randomised controlled trials on the benefits or harms of oxycodone when used to treat pain in fibromyalgia.

Quality of the evidence

We rated the quality of the evidence as very low because there were no studies. Very low quality evidence means that we are very uncertain about the results.

Authors' conclusions: 

There is no randomised trial evidence to support or refute the suggestion that oxycodone, alone or in combination with naloxone, reduces pain in fibromyalgia.

Read the full abstract...
Background: 

This review replaces part of an earlier review that evaluated oxycodone for both neuropathic pain and fibromyalgia, which has now been split into separate reviews for the two conditions. This review will consider pain in fibromyalgia only.

Opioid drugs are commonly used to treat fibromyalgia, but they may not be beneficial for people with this condition. Most reviews have examined all opioids together. This review sought evidence specifically for oxycodone, at any dose, and by any route of administration.

Objectives: 

To assess the analgesic efficacy and adverse events of oxycodone for treating pain in fibromyalgia in adults.

Search strategy: 

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE for randomised controlled trials from inception to 25 July 2016. We also searched the reference lists of retrieved studies and reviews, and searched online clinical trial registries.

Selection criteria: 

We planned to include randomised, double-blind trials of eight weeks' duration or longer, comparing oxycodone (alone or in fixed-dose combination with naloxone) with placebo or another active treatment. We did not include observational studies.

Data collection and analysis: 

The plan was for two independent review authors to extract data and assess trial quality and potential bias. Where pooled analysis was possible, we planned to use dichotomous data to calculate risk ratio and numbers needed to treat for one additional event, using standard methods.

Main results: 

No study satisfied the inclusion criteria. Effects of interventions were not assessed as there were no included studies. We have only very low quality evidence and are very uncertain about estimates of benefit and harm.