Breakthrough pain in chronic non-cancer pain: Fact, fiction, or abuse

Abstract

Treatment of chronic non-cancer pain with opioid therapy has escalated in recent years, resulting in exploding therapeutic use and misuse of prescription opioids and multiple adverse drug events. Breakthrough pain is defined as a transient exacerbation of pain experienced by individuals who have relatively stable and adequately controlled baseline cancer pain. Further, the definition of breakthrough pain, prevalence, characteristics, implications, and treatment modalities have been extensively described for chronic cancer pain. However, the literature for breakthrough pain in chronic non-cancer pain including its terminology, prevalence, relevance, characteristics, and treatments, have been poorly described and continue to be debated. The philosophy of breakthrough pain in chronic non-cancer pain raises multiple issues leading almost all patients to be on high dose long-acting opioids, followed by supplementing with short-acting drugs, instead of treating the patients with only shortacting drugs as required. Consequently, the subject of breakthrough pain in chronic non-cancer pain is looked at with suspicion due to the lack of evidence and inherent bias associated with its evaluation, followed by escalating use and abuse of opioids. Multiple issues related to the concept of breakthrough pain in chronic non-cancer pain evolve around extensive use, overuse, misuse, and abuse of opioids. In the era of eliminating opioids or significantly curtailing their use to only appropriate indications, the concept of breakthrough pain raises multiple questions without any scientific evidence. This review illustrates that there is no significant evidence for any type of breakthrough pain in chronic non-cancer pain based on available literature, methodology utilized, and response to opioids in chronic non-cancer pain. The advocacy for increased usage of opioids in the treatment of chronic pain dates back to the liberalization of laws governing opioid prescription for the treatment of chronic non-cancer pain by state medical boards in the late 1990s, and is exploding with new pain management standards for inpatient and outpatient medical care implemented by the Joint Commission on Accreditation of Health Care Organizations in 2000, and the advocacy by many physicians and organizations for increased use of opioids. This comprehensive review critically evaluates the available evidence of breakthrough pain in chronic non-cancer pain including its existence, prevalence, and managing symptoms which are described as breakthrough pain or episodic pain.