Objectives: To provide a guide to the use and limitations of continuous opioid therapy (COT, or daily scheduled opioids) for refractory daily headache, based on the best available evidence and expert clinical experience.
Background: There has been a dramatic increase in opioid administration over the past 25 years, with limited evidence of efficacy for either pain reduction or increased function, and increasing evidence of adverse effects, including headache chronification. To date, there has been no consensus on headache-specific guidelines for selecting patients for COT, physician requirements, and treatment monitoring.
Methods: A multidisciplinary committee of physicians and allied health professionals with extensive experience and expertise in the administration of opioids to headache patients, undertook a review of the available evidence from the research and clinical literature (using the PubMed database for articles through December 2009) to develop headache-specific treatment recommendations. This guide reflects the opinions of its authors and is not an official document of the American Headache Society.
Results: The guide identifies factors that would qualify or disqualify the use of COT, including, determination of intractability prior to initiating COT, requisite experience of the prescriber, and requirements for a formal monitoring system to assess appropriate use, safety, efficacy, and functional impact. An appendix reviews the available evidence for efficacy of COT in chronic headache and noncancer pain, paradoxical effects (opioid-induced hyperalgesia, medication overuse headache, opioid-related reduction in triptan and nonsteroidal anti-inflammatory drug efficacy), other adverse effects (nausea and constipation, insomnia and sleep apnea, respiratory depression and sudden cardiac death, reductions in sex hormones, issues during pregnancy, neurocognitive functioning), and issues related to comorbid psychiatric disorders.
Conclusions: Only a select and very limited group (estimate of 10-20%) of refractory headache patients who meet criteria for COT respond with convincing headache reduction and functional improvement over the long-term. Conservative and empirically based guidelines will help identify those patients for whom a COT trial may be appropriate, while protecting their welfare and safety.