The majority of chronic pain is thought to be caused by the following three mechanisms, either separately or in combination:1
- Nociceptive – damage to the tissues due to trauma or inflammation
- Neuropathic – damage to the nerve
- Hypersensitivity to pain
Ideally, pain treatment is targeted to the type of pain a person is experiencing. However, there is often more than one type and some conditions have multiple causes. For example, low back pain can be a result of both neuropathic and nociceptive causes.
In addition to use with chronic conditions, opioids can be appropriate first line agents for nociceptive acute pain caused by trauma, surgery or inflammation. The following table reflects the appropriate treatment by medication class for specific types of pain.