Updates & Features
Lack of clear and consistent definition for chronic neuropathic intractable or refractory pain
October 2018
What are the implications for a lack of a clear definition?
PainSolve Editorial Team
Unmet need in chronic neuropathic pain treatment
Most patients with chronic neuropathic pain are treated with medications as the mainstay of therapy, and yet most medically treated patients continue to report ongoing pain. A recent evidence-based review of medical therapy for neuropathic pain concluded that “existing pharmacologic treatments for neuropathic pain are limited, with no more than 40-60% of patients obtaining partial relief of their pain.”1 This means that roughly half of all patients with common conditions, such as diabetic peripheral neuropathy, lumbar radiculopathy or postsurgical neuropathic pain will not have sufficient improvement with conservative pain care measures.2
What is refractory and intractable pain?
Chronic neuropathic pain not responding to multiple treatment options is often called “refractory” or “intractable” pain. According to medical dictionary, intractable pain is “Chronic pain that is difficult or impossible to manage with standard interventions”, whereas the term refractory stands for “not responding to treatment”. Both terms are generally used synonymously. However, different definitions have been given in the literature, and whilst these definitions share some common features, issues arise when they are not used consistently across publications and there is divergence across sources.3 Treatments often state specific indications for either refractory or intractable pain, which can cause confusion for clinicians. For example, in 2004, Ziconotide (Prialt®) was approved by the FDA for treatment of severe refractory pain, and more recently in 2015 the spinal cord stimulation system (Senza System) was approved for intractable pain of the trunk and/or limbs.
Refractory or intractable – choose your words carefully
The term “intractable” may have a negative association for both the treating physician and the patient, because it gives the impression that the pain cannot be adequately relieved anymore. For the clinician it may also mean: “I am not going to treat you because it is not going to work”. The term “refractory” may be understood as pain which is not adequately controlled by some treatments but may be relieved by others.
The importance of a clear definition
A continued pharmacological drug rotation, strong opioids, spinal cord stimulation or intrathecal drug delivery are indicated for patients with chronic refractory or intractable pain.2,4 However, the lack of clear definition makes it challenging for the clinicians to decide when to prescribe more invasive treatment options. There are guidelines for chronic pain management, but there are no guidelines for the treatment of chronic refractory or intractable pain.
A consistent, clinically relevant definition of chronic refractory or refractory neuropathic pain would facilitate selection of appropriate interventions to enhance patient outcomes, as well as provide a foundation for future clinical research. A clear definition would also allow the prevalence of patients within different chronic neuropathic pain indications to be assessed.
References
- Dworkin RH, et al. Pain 2007; 132: 237-51
- Lamer TJ, et al. Mayo Clin Proc 2016; 91: 246-58
- Deer TR, et al. Neuromodulation 2014; 17: 711-5
- Wallace MS. Expert Rev Neurother 2006; 6: 1423-8