The World Health Organization (WHO) recommends a pain ladder for managing analgesia. In the treatment of chronic pain, whether due to malignant or benign processes, the three-step WHO Analgesic Ladder provides guidelines for selecting the kind and stepping up the amount of analgesia. The exact medications recommended will vary with the country and the individual treatment center, but the following gives an example of the WHO approach to treating chronic pain with medications. If, at any point, treatment fails to provide adequate pain relief, then the doctor and patient move onto the next step.
Figure 2. New adaptation of the analgesic ladder
NSAID-nonsteroidal anti-inflammatory drug, PCA-patient-controlled analgesia.
Paracetamol (acetaminophen), or a nonsteroidal anti-inflammatory drug (NSAID)
Paracetamol, an NSAID and/or paracetamol in a combination product with a weak opioid such as tramadol
When treating moderate to severe pain, the type of the pain, acute or chronic, needs to be considered. The type of pain can result in different medications being prescribed. Certain medications may work better for acute pain, others for chronic pain, and some may work equally well on both. Acute pain medication is for rapid onset of pain such as from an inflicted trauma or to treat post-operative pain. Chronic pain medication is for alleviating long-lasting, ongoing pain.
Morphine is the gold standard to which all narcotics are compared. Fentanyl has the benefit of less histamine release and thus fewer side effects. It can also be administered via transdermal patch which is convenient for chronic pain management. In addition to the intrathecal patch. Diamorphine, methadone and buprenorphine are used less frequently
For moderate pain, tramadol, codeine, dihydrocodeine, and hydrocodone are used,
Drugs of other types can be used to help opioids combat certain types of pain, for example, amitriptyline is prescribed for chronic muscular pain in the arms, legs, neck and lower back with an opiate, or sometimes without it and/or with an NSAID.
While opiates are often used in the management of chronic pain, high doses are associated with an increased risk of opioid overdose & drug addiction in long term use.
The other major group of analgesics are nonsteroidal anti-inflammatory drugs (NSAID). They work by inhibiting the release of prostaglandins, which cause inflammatory pain. Acetaminophen/paracetamol is not always included in this class of medications. However, acetaminophen may be administered as a single medication or in combination with other analgesics (both NSAIDs and opioids). The alternatively prescribed NSAIDs such as ketoprofen and piroxicam have limited benefit in chronic pain disorders and with long-term use are associated with significant adverse effects. The use of selective NSAIDs designated as selective COX-2 inhibitors have significant cardiovascular and cerebrovascular risks which have limited their utilization. Common NSAIDs include aspirin, ibuprofen, and naproxen.
|Salicylic derivates||Acetylsalicylic acid (Aspirin),Sodium salicylate, Diflunisal Salicylsalicylic acid, Sulfasalazine, Olsalazine|
|Indol and indene acetic acid||Indomethacin, Sulindac, Etodolac|
|Heteroary acetic acid||Ibuprofen, Neproxen, Fluubiprofen, Ketoprofen, Fenoprofen, Oxaprozin|
|Anthranilic acid (fenemates)||Mefenamic acid, Meclofenamic acid|
|Enolic acid derivatives (oxicams)||Piroxicam, Tenoxicam, Meloxicam|
"According to the National Institutes of Health, studies have shown that properly managed medical use of opioid analgesic compounds (taken exactly as prescribed) is safe, can manage pain effectively, and rarely causes addiction."
Opioid medications can provide short, intermediate or long acting analgesia depending upon the specific properties of the medication and whether it is formulated as an extended release drug. Opioid medications may be administered orally, by injection, via nasal mucosa or oral mucosa, rectally, transdermal, intravenously, epidurally and intrathecally. Most opioid treatment used by patients outside of healthcare settings is oral (tablet, capsule or liquid), but suppositories and skin patches can be prescribed. An opioid injection is rarely needed for patients with chronic pain.
Although opioids are strong analgesics, they do not provide complete analgesia regardless of whether the pain is acute or chronic in origin. Opioids are efficacious analgesics in chronic malignant pain and modestly effective in nonmalignant pain management. However, there are associated adverse effects, especially during the commencement or change in dose. When opioids are used for prolonged periods drug tolerance, chemical dependency, diversion and addiction may occur.
Some antidepressant and antiepileptic drugs are used in chronic pain management and act primarily within the pain pathways of the central nervous system, though peripheral mechanisms have been attributed as well. They are generally used to treat nerve brain that results from injury to the nervous system. Neuropathy can be due to chronic high blood sugar levels (diabetic neuropathy); and viruses, such as shingles; or post-stroke pain. These mechanisms vary and in general are more effective in neuropathic pain disorders as well as complex regional pain syndrome. A common anti-epileptic drug is gabapentin, and an example of an antidepressant would be amitriptyline.