Opioid rotation in chronic non-malignant pain patients - A retrospective study

Background: The clinical advantage of opioid rotation is probably due to incomplete cross-tolerance favouring analgesia more than adverse effects. The objectives of opioid rotation in chronic non-malignant patients are 1): rotation between different long-acting opioids (LAO) to improve analgesia and reduce side-effects, and 2): rotation from short-acting opioids (SAO) to LAO to establish stable analgesia in order to minimise withdrawal symptoms, risk of tolerance and addiction. Methods: A retrospective analysis of 37 rotations between different LAO and 59 rotations from SAO to LAO. Results The main reason for opioid rotation was insufficient pain relief. Opioid rotations resulted in significantly better pain control in 59% (CI95=49-76%) of the patients rotated between different LAO and 73% (CI95 =60-84%) of the patients rotated from SAO to LAO. During rotations symptoms of withdrawal and overdosing were relatively frequent in both groups. No significant dose changes were seen when rotating between different LAO. However, the consequence of rotation from SAO to LAO was a 74% increase in the opioid dose (CI95 =30-117%). Conclusion: Opioid rotations between different LAO resulted in better pain control and fewer side-effects at dose levels predicted to be equianalgesic. The majority of the patients rotated from SAO to LAO obtained improved analgesia, but the cost was a 74% increase in the opioid dose.