There is a range of pain medications available to relieve arthritic and musculoskeletal pain, as well as post-surgical pain. In general, drugs that relieve pain are called analgesics or, more commonly, painkillers. These drugs vary in potency and in how they work, and can be administered in different ways, including via pills, skin patches, injections, or intravenously.
Analgesics are frequently divided into two categories: opioids and non-opioids.
- Opioids are often referred to as narcotics
- Non-opioids include both non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen
Commonly called narcotics, opioid analgesics include medications derived from naturally occurring opiates (e.g. codeine and morphine) as well as man-made opioids (e.g. oxycodone). This group of drugs provides fast and effective pain relief and is usually reserved for treatment of severe pain. Demerol, OxyContin, and Vicodin are all name-brand examples of opioid analgesics.
While these drugs play a crucial role in medical pain relief, they carry risks and side effects. For example:
- Opioids can make patients feel foggy and drowsy, as well as cause constipation, itching, and nausea.
- Patients taking opioids to relieve chronic pain will develop a tolerance to the drugs over time, meaning that their bodies require higher doses to achieve the same level of pain relief.
- Narcotics, or opioids, can be addictive, particularly to people who have had addiction problems in the past. 1 Portenoy RK. Treatment of Pain. The Merck Manual, Home Edition. http://www.merckmanuals.com/home/brain_spinal_cord_and_nerve_disorders/pain/treatment_of_pain.html. Updated August 2007. Accessed November 10, 2014.
Patients are advised to research the potential risks and side effects of opioids, especially if taking them for more than a one- or two-week period.
NSAIDs and Acetaminophen
Non-opioid analgesics used to treat arthritis and musculoskeletal pain include non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen.
NSAIDs are designed to reduce inflammation and relieve mild to moderate pain. Depending on their formula, NSAIDs are available over the counter or by prescription. For example, the NSAIDs ibuprofen is sold under the brand name Advil, and naproxen is sold under the brand name Aleve, and they are sold in prescription-strength formulas.
Most NSAIDs block COX-1 and COX-2 enzymes.
- COX-1 enzymes influence blood clotting and the health of the stomach lining
- COX-2 enzymes influence inflammation that can lead to pain
A special class of NSAIDs block only COX-2 enzymes. Called COX-2 inhibitors, these drugs are less likely to affect blood clotting or cause harm to the stomach. Sold only with a prescription, COX-2 inhibitors include celecoxib, which is sold under the brand name Celebrex.
NSAIDs can cause side effects, most commonly stomach discomfort, heartburn, diarrhea, or constipation. There is also some evidence that NSAIDs and COX-2 inhibitors may interfere with bone healing, an obvious concern for patients undergoing joint replacement surgery.
Another non-opioid analgesic commonly used to treat musculoskeletal pain is acetaminophen. Acetaminophen does not address inflammation, but rather it works by interfering with the brain's ability to process pain signals. It is commonly sold under the brand name Tylenol.
Acetaminophen has relatively few side effects; however, this drug is processed by the liver and patients should note:
- Exceeding the recommended dose per day can cause liver damage.
- Some brands of opioids (narcotics), such as Vicodin, contain acetaminophen. Patients who take opioids or other medications are advised to check with a doctor or pharmacist before taking acetaminophen. (On prescription drug labels, acetaminophen may be listed as “APAP.”)
- Taking acetaminophen and drinking alcohol can cause liver damage. The FDA warns that patients who take safe doses of acetaminophen but drink three or more alcoholic drinks during the day can increase their risk of liver damage. 2 Acetaminophen and Liver Injury: Q & A for Consumers. US Food and Drug Administration. http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm168830.htm. Date posted June 24, 2009. Page last updated January 21, 2015. Accessed February 9, 2015.
Like all medications, the benefits and drawbacks of the non-opioid analgesics must be considered.
Patient-Controlled Intravenous Analgesia
Following surgery, patients may be given control of their own pain medication. For example, in the day(s) following a joint replacement surgery, a patient may be given a patient-controlled analgesia (PCA) pump during their hospital stay. The patient can press a button to self-administer doses of pain relieving drugs.
The medication—typically an opioid such as morphine or fentanyl—is delivered through an IV. The pump is programmed to deliver doses specific to the patient, so there is no risk of overdose.
- 1 Portenoy RK. Treatment of Pain. The Merck Manual, Home Edition. http://www.merckmanuals.com/home/brain_spinal_cord_and_nerve_disorders/pain/treatment_of_pain.html. Updated August 2007. Accessed November 10, 2014.
- 2 Acetaminophen and Liver Injury: Q & A for Consumers. US Food and Drug Administration. http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm168830.htm. Date posted June 24, 2009. Page last updated January 21, 2015. Accessed February 9, 2015.