Digestion, Heart, Pain, General | October 20, 2015 | Author: The Super Pharmacist
Nonsteroidal anti-inflammatory drugs or NSAIDs are the most important non-opioid class of pain relieving medications physicians have in their arsenal. For short-term use, NSAIDs are considered both safe and effective. Unfortunately, people who suffer from chronic pain disorders are faced with choosing between various drugs with potentially serious side effects. We review the current information on NSAID safety.
When discussing NSAID safety, one must consider the cyclooxygenase (COX) enzyme. Drugs that block cyclooxygenase enzymes, such as NSAIDs, are helpful in many ways. They reduce inflammation and fever, and modestly thin the blood (which can be helpful in certain patients and harmful in others). COX inhibitors also relieve mild to moderate pain by blocking pain pathways. NSAIDs can be divided into three categories by how they block COX1:
Unfortunately, blocking cyclooxygenase can also cause a number of serious side effects. Blocking COX-1 decreases the production of protective substances in the stomach and duodenum. This can, over time, cause damage to the lining of the stomach and small intestine. Damage to the gastrointestinal lining can lead to internal bleeding. If internal bleeding is severe or takes place over a long period, it can lead to anaemia. Initial hopes were that selectively blocking COX-2 would allow patients to enjoy pain relief without gastrointestinal side effects. Unfortunately, studies of COX-2 inhibitors showed significant increases in cardiovascular risk and some were pulled from the market as a result.
Therefore, physicians and patients must balance the risks to the gastrointestinal tract and the cardiovascular system with the need for long-term pain relief. Nonselective NSAIDs are useful in people who do not have or who are not at risk for kidney or cardiovascular diseases. Selective NSAIDs, specifically celecoxib, may be useful in people who cannot tolerate NSAIDs because of gastrointestinal difficulties.
Unfortunately, countless people suffer from chronic daily pain and cannot avoid taking NSAIDs. In this case, a reasonable question is which NSAID is the safest? The answer to this question, it turns out, depends as much on how you use the NSAID as which one you choose.
NSAIDs are relatively safe drugs when used for a short periods, such as a few days. Conversely, NSAIDs are responsible for more than one in 10 adverse drug event hospitalisations.2 The risk of serious side effects increases significantly the longer that one takes daily doses of NSAIDs. The relative risk of serious upper gastrointestinal problems doubles in people taking an NSAID for greater than six months.3 Likewise, the risk of acute renal failure almost doubles when one takes NSAIDs for an entire year.4 Limiting the use of NSAIDs when possible is the best way to minimize side effects. Since the risk of side effects also increases with the dose of NSAIDs, patient should also take the lowest possible dose that provides the desired therapeutic action, e.g. pain relief.5
Patients with a history of, or who are at risk for, gastrointestinal bleeding may need to be treated with paracetamol rather than an NSAID. If an NSAID is required in these patients, the gastrointestinal tract may be protected by simultaneously prescribing medications that reduce acid in the stomach, specifically proton pump inhibitors, such as omeprazole.6 It may also be best to select an NSAID that is relatively more selective for the COX-2 enzyme than COX-1. Reasonable choices may be diclofenac or celecoxib.5
People who have atherosclerosis, a history of unstable angina or myocardial infarction, or a history of stroke must use NSAIDs with caution. COX-2 selective NSAIDs increase the absolute risk for adverse cardiovascular events in these individuals.7 Therefore, nonselective or COX-1 favoring NSAIDs may be best for initial therapy.5 It is also important to realize that ibuprofen interferes with aspirin's ability to beneficially affect platelets.8 Therefore, no one taking daily aspirin therapy for a heart condition should take it at the same time as they take ibuprofen.9 For these patients, naproxen may be the best choice.
People at significant risk for, or who have kidney disease, are in a difficult position when it comes to chronic pain relief. Nonselective NSAIDs negatively affect the kidneys in several ways. They increase the risk of acute renal failure and other forms of acute kidney injury, can increase blood pressure, interfere with electrolytes and fluid balance, and even increase the risk of renal cell cancer.10,11 COX-2 selective NSAIDs seem to be similarly destructive to the kidneys as nonselective NSAIDs12 and are generally avoided in people with chronic renal insufficiency.13 That said, short-term and intermediate-term use of low-dose, COX-2 selective NSAIDs may not pose a significant risk to people with moderate or even severe chronic kidney disease.14