Codeine for Acute Extremity Pain [Internet]

Excerpt

Injuries to the upper and lower extremities can result from myriad causes such as sprains, fractures, crushes, and thermal or chemical injuries. A frequent outcome of such injuries is pain, which can be classified as acute (lasting for minutes to weeks) or chronic (lasting months to years).^,

The goals of therapy for acute extremity pain include the recognition that the patient is experiencing pain, the rapid reduction of pain intensity, and the general minimization of discomfort until the cause of the pain is treated.^, Therapeutic options for acute pain control include both non-pharmacological (e.g., ice, splint, sling) and pharmacological choices depending on the level of pain associated with the injury. Non-opioid analgesics, such as nonsteroidal anti-inflammatory drugs (NSAIDs), N-acetyl-para-aminophenol (APAP) (i.e., acetaminophen, paracetamol), and salicylates, may be sufficient for mild to moderate pain. Whereas opioids (e.g., morphine, fentanyl, hydromorphone, hydrocodone, oxycodone, codeine), alone or in combination with a non-opioid, are often the next step for recalcitrant pain or as a starting point for severe pain.^,

Opioid prescribing practices have come under scrutiny in recent years as Canada and other jurisdictions battle with an opioid epidemic. For this and other reasons, there has been a desire to optimize opioid prescribing in those cases in which it is possible. The appropriate role of codeine for pain management is being questioned and is the focus of this report.

In Canada, several formulations of codeine are available for treatment of pain. Codeine is an agonist of primarily the mu receptor^, in the central nervous system and in peripheral tissues such as the gastrointestinal tract. It is metabolized in the liver by the cytochrome P450 isoenzyme CYP2D6 to various metabolites, including morphine,^, which accounts for some of its analgesic effect.^,, The rate of metabolism by the CYP2D6 isoenzyme is known to vary in the general population,^, which highlights the ranges of pain relief and side effects that can be observed when codeine is used.^, It is a relatively weak opioid, and may also be used in combination with APAP or NSAIDs to provide an additive analgesic effect.

This report is part of a series questioning the appropriate use of codeine in pain management. A previous report summarized and critically appraised evidence available in November 2020 on codeine for pain related to osteoarthritis of the knee and hip. Two other summaries with critical appraisal are in progress at the time of writing for the use of codeine for acute dental pain and pain related to Caesarean section. Other related CADTH reports on codeine include 3 summaries with critical appraisals from 2019.^– The first sought evidence on codeine for acute pain from urological or general surgery, the second sought evidence on codeine for pediatric patients with acute pain, and the third sought evidence on codeine for acute pain in patients undergoing orthopedic surgery.

The objective of this report is to investigate the clinical effectiveness of codeine or codeine combination products for the management of acute extremity pain.