Article Text
Abstract
Background Opioid-induced hyperalgesia (OIH) is a clinical phenomenon, characterised by increasing pain in patients who are receiving increasing doses of opioids. Many doctors are unaware of this phenomenon, often leading to a long latency between the classic presentation of the syndrome and its eventual recognition and treatment. There is no recognised management strategy for the treatment of OIH and several interventions have been used, with varying success.
Aim To review and assess the management of opioid-induced hyperalgesia in palliative patients.
Methods Electronic databases, grey literature, clinical trials registries and handsearching for studies describing OIH. Full papers were obtained if relevant and studies graded.
Results 30 papers were included in the analysis, including case reports and case series of a total of 54 patients. Clinical features included worsening or more widely distributed pain. 50% of patients also had myoclonus, 35% allodynia, and 15% agitation. 1 patient (2%) suffered a seizure. Ten different interventions were used for the management of OIH, with many patients receiving more than one intervention simultaneously. The most commonly used strategies included opioid discontinuation or reduction, adding the NMDA receptor antagonist methadone, or opioid rotation, most commonly to an opioid with a lower equivalent dose. The most effective strategies for managing OIH were opioid dose reduction, opioid rotation and discontinuation of opioid.
Conclusions Reasonable approaches to manage patients suspected of having OIH include reduction of opioid dose, discontinuation of opioid, opioid rotation, or instituting multi-modal analgesia with adjuvant therapies such as the NMDA receptor antagonist methadone, and spinal anaesthetic techniques where appropriate.