Opioid therapy is the first-line approach for moderate or severe pain in populations with active cancer. However, the comprehensive management of pain in patients with cancer also requires expertise in the use of the nonopioid analgesics, such as acetaminophen (paracetamol), non-steroidal antiinflammatory agents (NSAIDs), and a group of drugs referred to as "adjuvant" analgesics or coanalgesics. Adjuvant analgesics are drugs that are marketed for indications other than pain, but are potentially useful as analgesics when added to opioid therapy in patients with chronic pain syndromes. (See "Cancer pain management with opioids: Optimizing analgesia" and "Cancer pain management: Use of acetaminophen and nonsteroidal antiinflammatory drugs".)
A stepwise approach to management of cancer pain that includes both opioid and nonopioid drugs has been codified in the World Health Organization's (WHO) "analgesic ladder" approach to cancer pain management (figure 1) :
●Step 1, which represents mild to moderate cancer-related pain, suggests the use of acetaminophen or an NSAID, possibly combined with an adjuvant drug to provide additional analgesia, treat a side effect, or manage a coexisting symptom.
●For patients with moderate or severe pain, and those who do not achieve adequate relief with acetaminophen or an NSAID alone, treatment with a step 2 opioid (conventionally used for moderate pain) or a step 3 opioid (conventionally used for severe pain) is appropriate. On both steps 2 and 3, the use of an acetaminophen or an NSAID should be considered, as well as other drugs (adjuvants) to enhance analgesia or treat side effects.
The analgesic ladder approach is not an evidence-based guideline, but it provides a framework for the stepwise and systematic approach to managing cancer pain. (See "Cancer pain management: General principles and risk management for patients receiving opioids", section on 'General principles of pain management'.)