Pain is considered as the fifth vital sign. Therefore, proper treatment of acute or chronic pain is important for improving the quality of life of patients. The use of opioids for the treatment of cancer pain, as first proposed in the guidelines released in 1986 by the World Health Organization (WHO), is now supported by more than 30 years of clinical experience. The WHO ladder is a stepwise approach to pain management where the first step (Step 1) recommends treating mild pain with nonopioid analgesics such as acetaminophen or nonsteroidal antiinflammatory drugs. For moderate pain relief, Step 2 of the ladder recommends using a moderate μ-opioid receptor agonist in combination with a nonopioid medication. This protocol is also effective in treating moderate postoperative pain. For more severe pain, Step 3 recommends the use of a stronger opioid and round the clock schedule monitoring of severe pain. The WHO pain ladder lists codeine, hydrocodone, and tramadol as “weak opioids,” and morphine, oxycodone, methadone, hydromorphone, and fentanyl as “strong opioids.” Unfortunately, both strong and opioids are misused or abused and as a result opioid epidemic become a public health emergency. Therefore, both patients and physicians must be aware of the abuse potential of opioids.
Elsevier, Fighting the Opiod Epidemic, 2020, Pages 43-60