Medication for chronic pain
Using medication to treat chronic pain
When a patient has a chronic pain condition, several pharmacologic treatment modalities exist to address the pain. In choosing a medication for pain control, physicians must first correctly diagnose the type of pain a patient is experiencing: inflammation, injury, nociceptive pain, or neuropathic pain.
Inflammation occurs when the body produces white blood cells and substances in order to protect us from infection and is also common in autoimmune diseases, such as arthritis. While natural, this protective process may stimulate nerves and cause pain.
Chronic pain may arise from an initial injury, such as a back sprain, and persist for weeks, months, or even years if left untreated.
Nociceptive pain results from tissue damage. Nociceptive pain can be subdivided into somatic and visceral (gut) pain and can be experienced as either a sharp sensation, a dull pain, or ache. Nociceptive pain is most commonly treated with anti-inflammatory and analgesic medications, such as non-steroidal anti-inflammatory drugs (NSAIDS) and opioids.
Neuropathic pain is associated with injury to the nerve. Often this type of pain is characterized by burning sensations, increased sensitivity, or shooting sensations over the affected area. Neuropathic pain is treated using medications that act on neurotransmitters and excitable nerves (e.g., antidepressants, anticonvulsant agents).
The different types of pain medications
The following categories contain the most commonly prescribed and most well-documented agents for the treatment of various forms of chronic pain.
Nociceptive pain medications
Nociceptive pain is generally responsive to and first treated with non-steroidal anti-inflammatory drugs (NSAIDs), followed with opioids for more severe or refractory pain. Conditions associated with inflammation, bone pain, and joint disease are particularly responsive to NSAIDs. This category of pain medication includes Acetaminophen (Tylenol), NSAIDs (aspirin, ibuprofen, Advil, Motrin, Aleve, etc), and COX 2 Inhibitors.
An opioid is a chemical substance that has a morphine-like action in the body. The term opioid is derived from opium, which is an extract from the poppy plant. When treating chronic pain, narcotic opioids should be considered if pain cannot be otherwise controlled. Although these medications can be dangerous and addicting, they can also be effective when used appropriately.
- Natural opioids: Alkaloids contained in the resin of the opium poppy (morphine, codeine, thebaine, and oripavine)
- Semi-synthetic opioids: From the natural opioids (hydromorphone, hydrocodone, oxycodone, and heroin)
- Fully-synthetic opioids: Produced synthetically (fentanyl, pethidine, methadone, and propoxyphene)
- Endogenous opioid peptides: Produced naturally in the body (endorphins, enkephalins, dynorphins, and endorphins)
Neuropathic pain seems to respond best to membrane-stabilizing medications. These medications are made up of the anti-convulsants, tricyclic antidepressants, and select antidepressant medications. These medications act by blocking the brain’s neurotransmitters. The antidepressant medications also have beneficial effects of improved mood, decreased anxiety, and improved sleep cycle. These medications are not addictive and, when appropriately managed, have few side effects.