The WHO Pain Ladder: Do We Need Another Step?
Editor’s Note:The World Health Organization (WHO) Pain Ladder has been an enduring guide for over 25 years. Its simple, progressive steps of 1) anti-inflammatory agents, 2) weak opioids, and 3) strong opioids is still fundamentally sound. In this article, Pergolizzi and Raffa present a thoughtful and detailed set of recommendations to modify the 3-step process. No doubt all of us have some thoughts about modifying the “WHO Pain Ladder,” based on the many new physical, interventional, and pharmacologic measures that have come forward since 1986. My message is that too many purveyors of potent opioid pharmaceuticals and invasive interventions have promoted and championed the use of these therapies, which have well-known complications, without first attempting regimens that are less onerous. Practical Pain Management desires that all pain practitioners make 2014 a year in which they develop and practice a “WHO Pain Ladder” protocol that is modified with some new measures to give our patients their best chance at a wide range of safe alternatives before resorting to potent opioids and invasive interventions.
The World Health Organization (WHO) created a practical pain ladder diagram in 1986 to help guide clinicians treating cancer pain throughout the world.1 The pain ladder was designed intentionally to be extremely simple: there are 3 rungs to the ladder, corresponding to increasing pain intensity. The clinician prescribes medications as pain worsens, moving from one rung to the next. Few medical guidelines have had the profound effect on care and the longevity of the 3-step WHO pain ladder, and the unofficial adoption of the WHO ladder for use in other pain syndromes, including nonmalignant pain, speaks to its relevance and utility.2
Over the years, however, the WHO pain ladder has been criticized with varying degrees of fairness. The soundest critique of the pain ladder is that it was created in 1986 and has not been modified since that time, despite intervening breakthroughs in our understanding of pain, pain control, and the introduction of new methods to treat pain.3 For example, opioid analgesics have expanded to include new agents, fast-acting and controlled-release formulations, and fixed-dose combination products. New approaches to pain control, such as neuromodulation, nerve blocks, intrathecal drug administration, and non-pharmaceutical protocols also have been developed. Today we have a better understanding of the multiple mechanisms underlying cancer pain and the phenomenon known as breakthrough pain.
Therefore, the authors propose some changes to the 1986 pain ladder to bring it up to date (Table 1). First, we wish to emphasize fixed-dose combination products, such as acetaminophen and hydrocodone, as important Step 2 agents. Second, the designation of “weak” and “strong” opioids may not be as meaningful as understanding the characteristics of specific opioid agents and their appropriate doses. Finally, the authors propose that a fourth rung be added to the ladder to allow for interventional pain management efforts, such as peripheral nerve blockade and neurolysis, which may be appropriate for the 10% to 15% of cancer patients who develop severe to very severe intractable pain. In addition, breakthrough pain should be recognized (although perhaps not as a rung on the ladder) with the recommended treatment option of a fast-acting opioid analgesic. Optimal pain control is multimodal and individualized. This does not negate the value of the generalized WHO pain ladder, but clinicians should feel free to modify it, as needed, for individual patients, reflecting modern pain practice.
Scope of Pain Problem
Nine million new cases of cancer are reported each year, the majority of which occur in developing nations.4 Oncologists all over the world focus on disease management rather than pain control,5 with the result that much cancer pain is undertreated or entirely untreated. Concern over palliative patients dying in severe (and potentially manageable) pain has been recognized as a public health crisis and a human rights issue.6 Pain is one of the most frequently reported severe symptoms of cancer patients.7 Pain is more than just physical suffering; it can reduce a patient’s ability to work, interact socially, sleep, and live a normal life. In advanced cancer patients receiving hospice care, pain significantly affects cognitive impairment and is associated with depression.8 A cross-sectional study found that pain affected emotional life in 71.5% of cancer patients and disrupted sleep in 88%.9 There is some evidence that effective analgesia may increase cancer survival.10 There is a very strong case to be made that cancer pain must be better managed, particularly now when more people are living longer with cancer.
A New Paradigm in Pain Management
When the WHO first published their pain ladder in 1986, it offered guidance for clinicians around the world in treating cancer pain.1 What made this simple diagrammatic ladder so enduring is the fact that it was intuitively understandable and could be immediately implemented anywhere in the world, including under-developed nations and regions with few pain specialists. A quarter century later, the use of the WHO pain ladder still offers effective and cost-effective pain relief for patients suffering from cancer pain, even those near end of life.
The WHO pain ladder (Figure 1) describes pain in terms of intensity and recommends that analgesics be prescribed starting at Step 1 (nonopioid analgesics, such as acetaminophen or non-steroidal anti-inflammatory drugs [NSAIDs]). If the pain persists or worsens, the clinician prescribes pain relievers from Step 2, described as “weak opioids,” with or without a nonopioid or adjuvant therapy. At this point, if pain persists or worsens, the patient is administered a “strong opioid,” with or without a nonopioid or adjuvant therapy (Step 3). Thus, pain therapy is based on pain intensity and patients progress through the steps one by one, from lowest to highest, until pain relief is obtained. The terms “weak” and “strong” opioid are hardly used today but are readily understandable, even if it is more useful perhaps to speak in terms of dose. The WHO pain ladder lists codeine, hydrocodone, and tramadol as “weak opioids,” and morphine, oxycodone, methadone, hydromorphone, and fentanyl as “strong opioids.”