Non-steroidal anti-inflammatory drug
Encyclopedia
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s with analgesic
Analgesic
An analgesic is any member of the group of drugs used to relieve pain . The word analgesic derives from Greek an- and algos ....
and antipyretic
Antipyretic
Antipyretics ; an-tee-pahy-ret-iks; from the Greek anti, against, and pyreticus, are drugs or herbs that reduce fever. Normally, they will not lower body temperature if one does not have a fever. Antipyretics cause the hypothalamus to override an interleukin-induced increase in temperature...
(fever-reducing) effects and which have, in higher doses, anti-inflammatory
Anti-inflammatory
Anti-inflammatory refers to the property of a substance or treatment that reduces inflammation. Anti-inflammatory drugs make up about half of analgesics, remedying pain by reducing inflammation as opposed to opioids, which affect the central nervous system....
effects.
The term "nonsteroidal" is used to distinguish these drugs from steroids, which, among a broad range of other effects, have a similar eicosanoid
Eicosanoid
In biochemistry, eicosanoids are signaling molecules made by oxidation of twenty-carbon essential fatty acids, ....
-depressing, anti-inflammatory action. As analgesics, NSAIDs are unusual in that they are non-narcotic
Narcotic
The term narcotic originally referred medically to any psychoactive compound with any sleep-inducing properties. In the United States of America it has since become associated with opioids, commonly morphine and heroin and their derivatives, such as hydrocodone. The term is, today, imprecisely...
.
The most prominent members of this group of drugs are aspirin
Aspirin
Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...
, ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
, and naproxen
Naproxen
Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...
, all of which are available over the counter
Over-the-counter drug
Over-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
in many areas.
Medical uses
NSAIDs are usually indicated for the treatment of acute or chronic conditions where painPain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
and inflammation are present. Research continues into their potential for prevention of colorectal cancer
Colorectal cancer
Colorectal cancer, commonly known as bowel cancer, is a cancer caused by uncontrolled cell growth , in the colon, rectum, or vermiform appendix. Colorectal cancer is clinically distinct from anal cancer, which affects the anus....
, and treatment of other conditions, such as cancer and cardiovascular disease
Cardiovascular disease
Heart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
.
NSAIDs are generally indicated for the symptomatic relief of the following conditions:
- Rheumatoid arthritisRheumatoid arthritisRheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
- OsteoarthritisOsteoarthritisOsteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
- Inflammatory arthropathies (e.g. ankylosing spondylitisAnkylosing spondylitisAnkylosing spondylitis , previously known as Bekhterev's disease, Bekhterev syndrome, and Marie-Strümpell disease is a chronic inflammatory disease of the axial skeleton with variable involvement of peripheral joints and nonarticular structures...
, psoriatic arthritisPsoriatic arthritisPsoriatic arthritis is a type of inflammatory arthritis that, according to the National Psoriasis Foundation, will develop in up to 30 percent of people who have the chronic skin condition psoriasis...
, Reiter's syndrome) - Acute goutGoutGout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
- Dysmenorrhoea (menstrualMenstruationMenstruation is the shedding of the uterine lining . It occurs on a regular basis in sexually reproductive-age females of certain mammal species. This article focuses on human menstruation.-Overview:...
pain) - MetastaticCancerCancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
bone pain - HeadacheHeadacheA headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
and migraineMigraineMigraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea... - Postoperative pain
- Mild-to-moderate pain due to inflammation and tissue injury
- Pyrexia (feverFeverFever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
) - IleusIleusIleus is a disruption of the normal propulsive ability of the gastrointestinal tract.Ileus is commonly defined simply as bowel obstruction. However, authoritative sources define it as decreased motor activity of the GI tract due to non-mechanical causes...
- Renal colicRenal colicRenal colic is a type of abdominal pain commonly caused by kidney stones.-Presentation:The pain typically begins in the abdomen and often radiates to the hypochondrium or the groin. The pain is often colicky due to ureteric peristalsis, but may be constant...
- They are also given to neonate infants whose ductus arteriosusDuctus arteriosusIn the developing fetus, the ductus arteriosus , also called the ductus Botalli, is a shunt connecting the pulmonary artery to the aortic arch. It allows most of the blood from the right ventricle to bypass the fetus's fluid-filled lungs. Upon closure at birth, it becomes the ligamentum arteriosum...
is not closed within 24 hours of birth
Aspirin
Aspirin
Aspirin , also known as acetylsalicylic acid , is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. It was discovered by Arthur Eichengrun, a chemist with the German company Bayer...
, the only NSAID able to irreversibly inhibit COX-1, is also indicated for inhibition of platelet
Platelet
Platelets, or thrombocytes , are small,irregularly shaped clear cell fragments , 2–3 µm in diameter, which are derived from fragmentation of precursor megakaryocytes. The average lifespan of a platelet is normally just 5 to 9 days...
aggregation. This is useful in the management of arterial thrombosis
Thrombosis
Thrombosis is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel is injured, the body uses platelets and fibrin to form a blood clot to prevent blood loss...
and prevention of adverse cardiovascular events. Aspirin inhibits platelet aggregation by inhibiting the action of thromboxane A2.
In 2001 NSAIDs accounted for 70,000,000 prescriptions and 30 billion over-the-counter doses sold annually in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Adverse effects
The widespread use of NSAIDs has meant that the adverse effects of these drugs have become increasingly prevalent. The two main adverse drug reactionAdverse drug reaction
An adverse drug reaction is an expression that describes harm associated with the use of given medications at a normal dosage. ADRs may occur following a single dose or prolonged administration of a drug or result from the combination of two or more drugs...
s (ADRs) associated with NSAIDs relate to gastrointestinal (GI) effects and renal effects of the agents.
These effects are dose-dependent, and in many cases severe enough to pose the risk of ulcer perforation, upper gastrointestinal bleeding, and death, limiting the use of NSAID therapy. An estimated 10-20% of NSAID patients experience dyspepsia
Dyspepsia
Dyspepsia , also known as upset stomach or indigestion, refers to a condition of impaired digestion. It is a medical condition characterized by chronic or recurrent pain in the upper abdomen, upper abdominal fullness and feeling full earlier than expected when eating...
, and NSAID-associated upper gastrointestinal adverse events are estimated to result in 103,000 hospitalizations and 16,500 deaths per year in the United States, and represent 43% of drug-related emergency visits. Many of these events are avoidable; a review of physician visits and prescriptions estimated that unnecessary prescriptions for NSAIDs were written in 42% of visits.
NSAIDs, like all drugs, may interact with other medications. For example, concurrent use of NSAIDs and quinolone
Quinolone
The quinolones are a family of synthetic broad-spectrum antibiotics. The term quinolone refers to potent synthetic chemotherapeutic antibacterials....
s may increase the risk of quinolones' adverse central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
effects, including seizure.
Combinational risk
If a COX-2 inhibitorCOX-2 inhibitor
COX-2 selective inhibitor is a form of non-steroidal anti-inflammatory drug that directly targets COX-2, an enzyme responsible for inflammation and pain. Targeting selectivity for COX-2 reduces the risk of peptic ulceration, and is the main feature of celecoxib, rofecoxib and other members of this...
is taken, one should not use a traditional NSAID (prescription or over-the-counter) concomitantly. In addition, people on daily aspirin therapy (e.g. for reducing cardiovascular risk) need to be careful if they also use other NSAIDs, as the latter may block the cardioprotective effects of aspirin.
Cardiovascular
NSAIDs aside from aspirin, both newer COX-2 antagonists and traditional anti-inflammatories, increase the risk of myocardial infarctionMyocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
and stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
. They are not recommended in those who have had a previous heart attack
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
as they increase the risk of death and / or recurrent MI. Naproxen
Naproxen
Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...
seems least harmful.
NSAIDs aside from (low-dose) aspirin are associated with a doubled risk of symptomatic heart failure in patients without a history of cardiac disease. In patients with such a history, however, use of NSAIDs (aside from low-dose aspirin) was associated with more than 10-fold increase in heart failure. If this link is found to be causal, NSAIDs are estimated to be responsible for up to 20 percent of hospital admissions for congestive heart failure. In people with heart failure, NSAIDs increase mortality risk by approximately 1.2-1.3 for naproxen and ibuprofen, 1.7 for rofecoxib and celecoxib, and 2.1 for diclofenac.
Erectile dysfunction risk
A 2005 study linked long term (over 3 months) use of NSAIDs, including ibuprofen, with a 1.4 times increased risk of erectile dysfunctionErectile dysfunction
Erectile dysfunction is sexual dysfunction characterized by the inability to develop or maintain an erection of the penis during sexual performance....
. The report by Kaiser Permanente and published in the Journal of Urology, considered that "regular non-steroidal anti-inflammatory drug use is associated with erectile dysfunction beyond what would be expected due to age and other condition". The director of research for Kaiser Permanente added that "There are many proven benefits of non steroidals in preventing heart disease and for other conditions. People shouldn't stop taking them based on this observational study. However, if a man is taking this class of drugs and has ED, it's worth a discussion with his doctor".
Gastrointestinal
The main adverse drug reactions (ADRs) associated with use of NSAIDs relate to direct and indirect irritation of the gastrointestinalGastrointestinal tract
The human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
(GI) tract. NSAIDs cause a dual assault on the GI tract: the acidic molecules directly irritate the gastric mucosa, and inhibition of COX-1 and COX-2 reduces the levels of protective prostaglandins. Inhibition of prostaglandin synthesis in the GI tract causes increased gastric acid secretion, diminished bicarbonate secretion, diminished mucus secretion and diminished trophic effects on epithelial mucosa.
Common gastrointestinal ADRs include:
- Nausea/Vomiting
- DyspepsiaDyspepsiaDyspepsia , also known as upset stomach or indigestion, refers to a condition of impaired digestion. It is a medical condition characterized by chronic or recurrent pain in the upper abdomen, upper abdominal fullness and feeling full earlier than expected when eating...
- Gastric ulceration/bleeding.
- DiarrheaDiarrheaDiarrhea , also spelled diarrhoea, is the condition of having three or more loose or liquid bowel movements per day. It is a common cause of death in developing countries and the second most common cause of infant deaths worldwide. The loss of fluids through diarrhea can cause dehydration and...
Risk of ulceration increases with duration of therapy, and with higher doses. In attempting to minimise GI ADRs, it is prudent to use the lowest effective dose for the shortest period of time, a practice which studies show is not often followed. Recent studies show that over 50% of patients taking NSAIDs have sustained damage to their small intestine. Studies show that risk of ulceration is less with nabumetone than with ibuprofen alone.
There are also some differences in the propensity of individual agents to cause gastrointestinal ADRs. Indomethacin, ketoprofen
Ketoprofen
Ketoprofen, 2--propionic acid is one of the propionic acid class of non-steroidal anti-inflammatory drug with analgesic and antipyretic effects...
and piroxicam
Piroxicam
Piroxicam is a non-steroidal anti-inflammatory drug of the oxicam class used to relieve the symptoms of rheumatoid and osteoarthritis, primary dysmenorrhoea, postoperative pain; and act as an analgesic, especially where there is an inflammatory component...
appear to have the highest prevalence of gastric ADRs, while ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
(lower doses) and diclofenac
Diclofenac
Diclofenac is a non-steroidal anti-inflammatory drug taken to reduce inflammation and as an analgesic reducing pain in certain conditions....
appear to have lower rates.
Certain NSAIDs, such as aspirin, have been marketed in enteric-coated
Enteric coating
An enteric coating is a barrier applied to oral medication that controls the location in the digestive system, where it is absorbed. Enteric refers to the small intestine, therefore enteric coatings prevent release of medication before it reaches the small intestine.Most enteric coatings work by...
formulations which are claimed to reduce the incidence of gastrointestinal ADRs. Similarly, there is a belief that rectal formulations may reduce gastrointestinal ADRs. However, in consideration of the mechanism of such ADRs and indeed in clinical practice, these formulations have not been shown to have a reduced risk of GI ulceration.
Commonly, gastric (but not necessarily intestinal) adverse effects can be reduced through suppressing acid production, by concomitant use of a proton pump inhibitor
Proton pump inhibitor
Proton-pump inhibitors are a group of drugs whose main action is a pronounced and long-lasting reduction of gastric acid production. They are the most potent inhibitors of acid secretion available today. The group followed and has largely superseded another group of pharmaceuticals with similar...
, e.g. omeprazole
Omeprazole
Omeprazole is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease , gastroesophageal reflux disease , laryngopharyngeal reflux and Zollinger–Ellison syndrome...
, esomeprazole
Esomeprazole
Esomeprazole is a proton pump inhibitor developed and marketed by AstraZeneca which is used in the treatment of dyspepsia, peptic ulcer disease , gastroesophageal reflux disease and Zollinger-Ellison syndrome...
; or the prostaglandin analogue misoprostol
Misoprostol
Misoprostol is a drug that is used for the prevention of non steroidal anti inflammatory drug induced gastric ulcers, for early abortion, to treat missed miscarriage, and to induce labor. The latter use is controversial in the United States. Misoprostol was invented and marketed by G.D...
. Misoprostol is itself associated with a high incidence of gastrointestinal ADRs (diarrhea). While these techniques may be effective, they prove to be expensive for maintenance therapy.
Inflammatory bowel disease
NSAIDs are never to be used in individuals with inflammatory bowel diseaseInflammatory bowel disease
In medicine, inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine. The major types of IBD are Crohn's disease and ulcerative colitis.-Classification:...
(e.g., Crohn's disease
Crohn's disease
Crohn's disease, also known as regional enteritis, is a type of inflammatory bowel disease that may affect any part of the gastrointestinal tract from mouth to anus, causing a wide variety of symptoms...
or ulcerative colitis
Ulcerative colitis
Ulcerative colitis is a form of inflammatory bowel disease . Ulcerative colitis is a form of colitis, a disease of the colon , that includes characteristic ulcers, or open sores. The main symptom of active disease is usually constant diarrhea mixed with blood, of gradual onset...
) due to their tendency to cause gastric bleeding and form ulceration in the gastric lining. Pain relievers such as paracetamol
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...
(also known as acetaminophen) or drugs containing codeine
Codeine
Codeine or 3-methylmorphine is an opiate used for its analgesic, antitussive, and antidiarrheal properties...
(which slows down bowel activity) are safer medications for pain relief in IBD.
Renal
NSAIDs are also associated with a relatively high incidence of renal adverse drug reactions (ADRs). The mechanism of these renal ADRs is due to changes in renal haemodynamics (blood flow), ordinarily mediated by prostaglandins, which are affected by NSAIDs. Prostaglandins normally cause vasodilation of the afferent arterioles of the glomeruliGlomerulus
A glomerulus is a capillary tuft that is involved in the first step of filtering blood to form urine.A glomerulus is surrounded by Bowman's capsule, the beginning component of nephrons in the vertebrate kidney. A glomerulus receives its blood supply from an afferent arteriole of the renal...
. This helps maintain normal glomerular perfusion and glomerular filtration rate (GFR), an indicator of renal function
Renal function
Renal function, in nephrology, is an indication of the state of the kidney and its role in renal physiology. Glomerular filtration rate describes the flow rate of filtered fluid through the kidney...
. This is particularly important in renal failure where the kidney is trying to maintain renal perfusion pressure by elevated angiotensin II levels. At these elevated levels, angiotensin II also constricts the afferent arteriole into the glomerulus in addition to the efferent arteriole one it normally constricts. Prostaglandins serve to dilate the afferent arteriole; by blocking this prostaglandin-mediated effect, particularly in renal failure, NSAIDs cause unopposed constriction of the afferent arteriole and decreased renal perfusion pressure. Horses are particularly prone to these adverse affects compared with other domestic animal species.
Common ADRs associated with altered renal function include:
- Salt and fluid retention
- HypertensionHypertensionHypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
(high blood pressure)
These agents may also cause renal impairment, especially in combination with other nephrotoxic agents. Renal failure is especially a risk if the patient is also concomitantly taking an ACE inhibitor
ACE inhibitor
ACE inhibitors or angiotensin-converting enzyme inhibitors are a group of drugs used primarily for the treatment of hypertension and congestive heart failure...
and a diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
- the so-called "triple whammy" effect.
In rarer instances NSAIDs may also cause more severe renal conditions:
- Interstitial nephritisInterstitial nephritisInterstitial nephritis is a form of nephritis affecting the interstitium of the kidneys surrounding the tubules...
- Nephrotic syndromeNephrotic syndromeNephrotic syndrome is a nonspecific disorder in which the kidneys are damaged, causing them to leak large amounts of protein from the blood into the urine....
- Acute renal failureAcute renal failureAcute kidney injury , previously called acute renal failure , is a rapid loss of kidney function. Its causes are numerous and include low blood volume from any cause, exposure to substances harmful to the kidney, and obstruction of the urinary tract...
- Acute tubular necrosisAcute tubular necrosisAcute tubular necrosis or is a medical condition involving the death of tubular cells that form the tubule that transports urine to the ureters while reabsorbing 99% of the water . Tubular cells continually replace themselves and if the cause of ATN is removed then recovery is likely...
NSAIDs in combination with excessive use of phenacetin
Phenacetin
Phenacetin is an analgesic, once widely used; its use has declined because of its adverse effects.-History:Phenacetin was introduced in 1887, and was used principally as an analgesic, and was one of the first synthetic fever reducers to go on the market...
and/or paracetamol
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...
may lead to analgesic nephropathy.
Photosensitivity
PhotosensitivityPhotodermatitis
Photodermatitis, sometimes referred to as "sun poisoning" or photoallergy is a form of allergic contact dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure...
is a commonly overlooked adverse effect of many of the NSAIDs. The 2-arylpropionic acids have proven to be the most likely to produce photosensitivity reactions, but other NSAIDs have also been implicated including piroxicam
Piroxicam
Piroxicam is a non-steroidal anti-inflammatory drug of the oxicam class used to relieve the symptoms of rheumatoid and osteoarthritis, primary dysmenorrhoea, postoperative pain; and act as an analgesic, especially where there is an inflammatory component...
, diclofenac
Diclofenac
Diclofenac is a non-steroidal anti-inflammatory drug taken to reduce inflammation and as an analgesic reducing pain in certain conditions....
and benzydamine.
Benoxaprofen
Benoxaprofen
Benoxaprofen is a non-steroidal anti-inflammatory drug. It was marketed by Eli Lilly and Company under the brand name Oraflex in the US and as Opren in Europe. Lilly suspended sales of Oraflex in 1982 after reports from the British government and the U.S. Food and Drug Administration of adverse...
, since withdrawn due to its hepatotoxicity
Hepatotoxicity
Hepatotoxicity implies chemical-driven liver damage.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure...
, was the most photoactive NSAID observed. The mechanism of photosensitivity, responsible for the high photoactivity of the 2-arylpropionic acids, is the ready decarboxylation
Decarboxylation
Decarboxylation is a chemical reaction that releases carbon dioxide . Usually, decarboxylation refers to a reaction of carboxylic acids, removing a carbon atom from a carbon chain. The reverse process, which is the first chemical step in photosynthesis, is called carbonation, the addition of CO2 to...
of the carboxylic acid
Carboxylic acid
Carboxylic acids are organic acids characterized by the presence of at least one carboxyl group. The general formula of a carboxylic acid is R-COOH, where R is some monovalent functional group...
moiety
Functional group
In organic chemistry, functional groups are specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules. The same functional group will undergo the same or similar chemical reaction regardless of the size of the molecule it is a part of...
. The specific absorbance characteristics of the different chromophoric
Chromophore
A chromophore is the part of a molecule responsible for its color. The color arises when a molecule absorbs certain wavelengths of visible light and transmits or reflects others. The chromophore is a region in the molecule where the energy difference between two different molecular orbitals falls...
2-aryl substituents, affects the decarboxylation mechanism. While ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
has weak absorption, it has been reported to be a weak photosensitising agent.
During pregnancy
NSAIDs are not recommended during pregnancy, particularly during the third trimester. While NSAIDs as a class are not direct teratogens, they may cause premature closure of the fetal ductus arteriosusDuctus arteriosus
In the developing fetus, the ductus arteriosus , also called the ductus Botalli, is a shunt connecting the pulmonary artery to the aortic arch. It allows most of the blood from the right ventricle to bypass the fetus's fluid-filled lungs. Upon closure at birth, it becomes the ligamentum arteriosum...
and renal ADRs in the fetus. Additionally, they are linked with premature birth
Premature birth
In humans preterm birth refers to the birth of a baby of less than 37 weeks gestational age. The cause for preterm birth is in many situations elusive and unknown; many factors appear to be associated with the development of preterm birth, making the reduction of preterm birth a challenging...
and miscarriage
Miscarriage
Miscarriage or spontaneous abortion is the spontaneous end of a pregnancy at a stage where the embryo or fetus is incapable of surviving independently, generally defined in humans at prior to 20 weeks of gestation...
. Aspirin, however, is used together with heparin
Heparin
Heparin , also known as unfractionated heparin, a highly sulfated glycosaminoglycan, is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule...
in pregnant women with antiphospholipid antibodies.
In contrast, paracetamol
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...
(acetaminophen) is regarded as being safe and well-tolerated during pregnancy. Doses should be taken as prescribed, due to risk of hepatotoxicity
Hepatotoxicity
Hepatotoxicity implies chemical-driven liver damage.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure...
with overdoses.
In France, the country's health agency contraindicates the use of NSAIDs, including aspirin, after the sixth month of pregnancy.
Other
Common adverse drug reactions (ADR), other than listed above, include: raised liver enzymes, headacheHeadache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...
, dizziness
Dizziness
Dizziness refers to an impairment in spatial perception and stability. The term is somewhat imprecise. It can be used to mean vertigo, presyncope, disequilibrium, or a non-specific feeling such as giddiness or foolishness....
. Uncommon ADRs include: hyperkalaemia, confusion, bronchospasm
Bronchospasm
Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release of substances from mast cells or basophils under the influence of anaphylatoxins...
, rash. Rapid and severe swelling of the face and/or body. Ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
may also rarely cause irritable bowel syndrome
Irritable bowel syndrome
Irritable bowel syndrome is a diagnosis of exclusion. It is a functional bowel disorder characterized by chronic abdominal pain, discomfort, bloating, and alteration of bowel habits in the absence of any detectable organic cause. In some cases, the symptoms are relieved by bowel movements...
symptoms. NSAIDs are also implicated in some cases of Stevens–Johnson syndrome.
Most NSAIDs penetrate poorly into the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
(CNS). However, the COX enzymes are expressed constitutively in some areas of the CNS, meaning that even limited penetration may cause adverse effects such as somnolence and dizziness.
In very rare cases, ibuprofen can cause aseptic meningitis.
As with other drugs, allergies to NSAIDs might exist. While many allergies are specific to one NSAID, up to 1 in 5 people may have unpredictable cross-reactive allergic responses to other NSAIDs as well.
Drug Interactions
NSAIDs reduce renal blood flow and thereby decrease the efficacy of diureticDiuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
s, and inhibit the elimination of lithium
Lithium pharmacology
Lithium pharmacology refers to use of the lithium ion, Li+, as a drug. A number of chemical salts of lithium are used medically as a mood stabilizing drug, primarily in the treatment of bipolar disorder, where they have a role in the treatment of depression and particularly of mania, both acutely...
and methotrexate
Methotrexate
Methotrexate , abbreviated MTX and formerly known as amethopterin, is an antimetabolite and antifolate drug. It is used in treatment of cancer, autoimmune diseases, ectopic pregnancy, and for the induction of medical abortions. It acts by inhibiting the metabolism of folic acid. Methotrexate...
.
NSAIDs cause hypocoagulability, which may be serious when combined with other drugs that also decrease blood clotting, such as warfarin
Warfarin
Warfarin is an anticoagulant. It is most likely to be the drug popularly referred to as a "blood thinner," yet this is a misnomer, since it does not affect the thickness or viscosity of blood...
.
NSAIDs may aggravate hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
(high blood pressure) and thereby antagonize the effect of antihypertensives, such as ACE Inhibitor
ACE inhibitor
ACE inhibitors or angiotensin-converting enzyme inhibitors are a group of drugs used primarily for the treatment of hypertension and congestive heart failure...
s.
NSAIDs may interfere and reduce efficiency of SSRI antidepressants
Mechanism of action
Most NSAIDs act as nonselective inhibitors of the enzymeEnzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
cyclooxygenase
Cyclooxygenase
Cyclooxygenase is an enzyme that is responsible for formation of important biological mediators called prostanoids, including prostaglandins, prostacyclin and thromboxane. Pharmacological inhibition of COX can provide relief from the symptoms of inflammation and pain...
(COX), inhibiting both the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) isoenzymes. COX catalyzes the formation of prostaglandin
Prostaglandin
A prostaglandin is any member of a group of lipid compounds that are derived enzymatically from fatty acids and have important functions in the animal body. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring....
s and thromboxane
Thromboxane
Thromboxane is a member of the family of lipids known as eicosanoids. The two major thromboxanes are thromboxane A2 and thromboxane B2. The distinguishing feature of thromboxanes is a 6-membered ether-containing ring....
from arachidonic acid
Arachidonic acid
Arachidonic acid is a polyunsaturated omega-6 fatty acid 20:4.It is the counterpart to the saturated arachidic acid found in peanut oil, Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6).It is the counterpart to the saturated arachidic acid found in peanut oil,...
(itself derived from the cellular phospholipid
Phospholipid
Phospholipids are a class of lipids that are a major component of all cell membranes as they can form lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline; one exception to this rule is sphingomyelin, which is derived from...
bilayer by phospholipase A2
Phospholipase A2
Phospholipases A2 are enzymes that release fatty acids from the second carbon group of glycerol. This particular phospholipase specifically recognizes the sn-2 acyl bond of phospholipids and catalytically hydrolyzes the bond releasing arachidonic acid and lysophospholipids...
). Prostaglandins act (among other things) as messenger molecules in the process of inflammation
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
. This mechanism of action
Mechanism of action
In pharmacology, the term mechanism of action refers to the specific biochemical interaction through which a drug substance produces its pharmacological effect...
was elucidated by John Vane (1927–2004), who received a Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
for his work (see Mechanism of action of aspirin
Mechanism of action of aspirin
Aspirin causes several different effects in the body, mainly the reduction of inflammation, analgesia , the prevention of clotting, and the reduction of fever. Much of this is believed to be due to decreased production of prostaglandins and thromboxanes...
). Many aspects of the mechanism of action of NSAIDs remain unexplained, for this reason further COX pathways are hypothesized. The COX-3
COX-3
COX-3 is an enzyme that is encoded by the PTGS1 gene, but is not functional in humans. COX-3 is the third and most recently discovered cyclooxygenase isozyme, the others being COX-1 and COX-2...
pathway was believed to fill some of this gap but recent findings make it appear unlikely that it plays any significant role in humans and alternative explanation models are proposed.
NSAIDs are also used in acute gouty attack because they inhibit urate crystal phagocytosis besides inhibition of prostaglandin synthase.
Antipyretic activity
NSAIDS have antipyretic activity and can be used to treat fever. Fever is caused by elevated levels of prostaglandin E2, which alters the firing rate of neurons within the hypothalamusHypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
that control thermoregulation. Antipyretics work by inhibiting the enzyme COX, which causes the general inhibition of prostanoid
Prostanoid
Prostanoid is the term used to describe a subclass of eicosanoids consisting of: the prostaglandins , the thromboxanes and the prostacyclins - Biosynthesis : Cyclooxygenase catalyzes the conversion of the free essential fatty acids to...
biosynthesis (PGE2) within the hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
. PGE2 signals to the hypothalamus to increase the body's thermal set point. Ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
has been shown to be more effective as an antipyretic
Antipyretic
Antipyretics ; an-tee-pahy-ret-iks; from the Greek anti, against, and pyreticus, are drugs or herbs that reduce fever. Normally, they will not lower body temperature if one does not have a fever. Antipyretics cause the hypothalamus to override an interleukin-induced increase in temperature...
than acetaminophen.
Arachidonic acid
Arachidonic acid
Arachidonic acid is a polyunsaturated omega-6 fatty acid 20:4.It is the counterpart to the saturated arachidic acid found in peanut oil, Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6).It is the counterpart to the saturated arachidic acid found in peanut oil,...
is the precursor substrate for cyclooxygenase leading to the production of prostaglandins F,D & E.
Classification
NSAIDs can be classified based on their chemical structure or mechanism of action. Older NSAIDs were known long before their mechanism of action was elucidated and were for this reason classified by chemical structure or origin. Newer substances are more often classified by mechanism of action.Main practical differences
NSAIDs within a group will tend to have similar characteristics and tolerability. There is little difference in clinical efficacy among the NSAIDs when used at equivalent doses. Rather, differences among compounds tend to be with regards to dosing regimens (related to the compound's elimination half-life), route of administration, and tolerability profile.Regarding adverse effects, selective COX-2 inhibitors have lower risk of gastrointestinal bleeding, but a substantially more increased risk of myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
than the increased risk from nonselective inhibitors. Some data also supports that the partially selective nabumetone
Nabumetone
Nabumetone is a non-steroidal anti-inflammatory drug , the only 1-naphthaleneacetic acid derivative. Nabumetone has been developed by Beecham...
is less likely to cause gastrointestinal events. The nonselective naproxen
Naproxen
Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...
appears to be risk-neutral with regard to cardiovascular events.
A consumer report noted ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
, naproxen and salsalate
Salsalate
Salsalate is a non-steroidal anti-inflammatory drug . Salsalate is in a class of drugs called salicylates. Salsalate may work by inhibiting the production of and release of prostaglandins. Salsalate is the generic name of a prescription drug marketed under the brandnames Mono-Gesic, Salflex,...
to be less expensive than other NSAIDs and to be essentially as effective and safe as any of them when used appropriately in treating osteoarthritis and pain.
Pharmacokinetics
Most nonsteroidal anti-inflammatory drugs are weak acids, with a pKa of 3-5. They are absorbed well from the stomachStomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
and intestinal mucosa. They are highly protein-bound in plasma (typically >95%), usually to albumin
Human serum albumin
Human serum albumin is the most abundant protein in human blood plasma. It is produced in the liver. Albumin constitutes about half of the blood serum protein...
, so that their volume of distribution
Volume of distribution
The volume of distribution , also known as apparent volume of distribution, is a pharmacological term used to quantify the distribution of a medication between plasma and the rest of the body after oral or parenteral dosing...
typically approximates to plasma volume. Most NSAIDs are metabolised in the liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
by oxidation and conjugation to inactive metabolites which are typically excreted in the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
, although some drugs are partially excreted in bile
Bile
Bile or gall is a bitter-tasting, dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the process of digestion of lipids in the small intestine. In many species, bile is stored in the gallbladder and upon eating is discharged into the duodenum...
. Metabolism may be abnormal in certain disease states, and accumulation may occur even with normal dosage.
Ibuprofen and diclofenac have short half-lives (2–3 hours). Some NSAIDs (typically oxicams) have very long half-lives (e.g. 20–60 hours).
Chirality
Most NSAIDs are chiralChirality (chemistry)
A chiral molecule is a type of molecule that lacks an internal plane of symmetry and thus has a non-superimposable mirror image. The feature that is most often the cause of chirality in molecules is the presence of an asymmetric carbon atom....
molecules (diclofenac
Diclofenac
Diclofenac is a non-steroidal anti-inflammatory drug taken to reduce inflammation and as an analgesic reducing pain in certain conditions....
is a notable exception). However, the majority are prepared in a racemic
Racemic
In chemistry, a racemic mixture, or racemate , is one that has equal amounts of left- and right-handed enantiomers of a chiral molecule. The first known racemic mixture was "racemic acid", which Louis Pasteur found to be a mixture of the two enantiomeric isomers of tartaric acid.- Nomenclature :A...
mixture. Typically, only a single enantiomer
Enantiomer
In chemistry, an enantiomer is one of two stereoisomers that are mirror images of each other that are non-superposable , much as one's left and right hands are the same except for opposite orientation. It can be clearly understood if you try to place your hands one over the other without...
is pharmacologically active. For some drugs (typically profens), an isomerase
Isomerase
In biochemistry, an isomerase is an enzyme that catalyzes the structural rearrangement of isomers. Isomerases thus catalyze reactions of the formwhere B is an isomer of A.-Nomenclature:...
enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
exists in vivo which converts the inactive enantiomer into the active form, although its activity varies widely in individuals. This phenomenon is likely to be responsible for the poor correlation between NSAID efficacy and plasma concentration observed in older studies, when specific analysis of the active enantiomer was not performed.
Ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
and ketoprofen
Ketoprofen
Ketoprofen, 2--propionic acid is one of the propionic acid class of non-steroidal anti-inflammatory drug with analgesic and antipyretic effects...
are now available in single, active enantiomer preparations (dexibuprofen and dexketoprofen), which purport to offer quicker onset and an improved side-effect profile. Naproxen
Naproxen
Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...
has always been marketed as the single active enantiomer.
COX-2 inhibitors
The discovery of COX-2 in 1991 by Daniel L. SimmonsDaniel L. Simmons
Daniel L. Simmons is a professor of chemistry and the director of the Cancer Research Center at Brigham Young University . He was the discoverer of the COX-2 enzyme that is the target of celecoxib and other COX-2 inhibitors...
at Brigham Young University
Brigham Young University
Brigham Young University is a private university located in Provo, Utah. It is owned and operated by The Church of Jesus Christ of Latter-day Saints , and is the United States' largest religious university and third-largest private university.Approximately 98% of the university's 34,000 students...
raised the hope of developing an effective NSAID without the gastric problems characteristic of these agents. It was thought that selective inhibition of COX-2 would result in anti-inflammatory action without disrupting gastroprotective prostaglandins.
COX-1 is a constitutively expressed enzyme with a "house-keeping" role in regulating many normal physiological processes. One of these is in the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
lining, where prostaglandins serve a protective role, preventing the stomach mucosa from being eroded by its own acid. When nonselective COX-1/COX-2 inhibitors (such as aspirin, ibuprofen, and naproxen) lower stomach prostaglandin levels, these protective effects are lost and ulcers
Peptic ulcer
A peptic ulcer, also known as PUD or peptic ulcer disease, is the most common ulcer of an area of the gastrointestinal tract that is usually acidic and thus extremely painful. It is defined as mucosal erosions equal to or greater than 0.5 cm...
of the stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
or duodenum
Duodenum
The duodenum is the first section of the small intestine in most higher vertebrates, including mammals, reptiles, and birds. In fish, the divisions of the small intestine are not as clear and the terms anterior intestine or proximal intestine may be used instead of duodenum...
and potentially internal bleeding
Bleeding
Bleeding, technically known as hemorrhaging or haemorrhaging is the loss of blood or blood escape from the circulatory system...
can result. COX-2 is an enzyme facultatively expressed in inflammation, and it is inhibition of COX-2 that produces the desirable effects of NSAIDs.
The relatively selective COX-2 inhibiting oxicam, meloxicam
Meloxicam
Meloxicam is a nonsteroidal anti-inflammatory drug with analgesic and fever reducer effects. It is a derivative of oxicam, closely related to piroxicam, and falls in the enolic acid group of NSAIDs...
, was the first step towards developing a true COX-2 selective inhibitor. Coxibs, the newest class of NSAIDs, can be considered as true COX-2 selective inhibitors, and include celecoxib
Celecoxib
Celecoxib INN is a sulfa non-steroidal anti-inflammatory drug and selective COX-2 inhibitor used in the treatment of osteoarthritis, rheumatoid arthritis, acute pain, painful menstruation and menstrual symptoms, and to reduce numbers of colon and rectum polyps in patients with familial...
, rofecoxib
Rofecoxib
Rofecoxib is a nonsteroidal anti-inflammatory drug that has now been withdrawn over safety concerns. It was marketed by Merck & Co. to treat osteoarthritis, acute pain conditions, and dysmenorrhoea...
, valdecoxib
Valdecoxib
Valdecoxib is a non-steroidal anti-inflammatory drug used in the treatment of osteoarthritis, rheumatoid arthritis, and painful menstruation and menstrual symptoms. It is a cyclooxygenase-2 selective inhibitor....
, parecoxib
Parecoxib
Parecoxib is a water soluble and injectable prodrug of valdecoxib. It is marketed as Dynastat in the European Union. Parecoxib is a COX2 selective inhibitor in the same category as celecoxib and rofecoxib . As it is injectable, it can be used perioperatively when patients are unable to take oral...
and etoricoxib
Etoricoxib
Etoricoxib is a COX-2 selective inhibitor from Merck & Co...
.
Acetaminophen does also work mainly by blocking COX-2, unlike the newly developed COX-2 inhibitors it has weaker peripheral inhibitory activity.
Controversies with COX-2 inhibitors
While it was hoped that this COX-2 selectivity would reduce gastrointestinal adverse drug reactions (ADRs), there is little conclusive evidence that this is true. The original study touted by Searle (now part of PfizerPfizer
Pfizer, Inc. is an American multinational pharmaceutical corporation. The company is based in New York City, New York with its research headquarters in Groton, Connecticut, United States...
), showing a reduced rate of ADRs for celecoxib, was later revealed to be based on preliminary data - the final data showed no significant difference in ADRs when compared with diclofenac.
Rofecoxib
Rofecoxib
Rofecoxib is a nonsteroidal anti-inflammatory drug that has now been withdrawn over safety concerns. It was marketed by Merck & Co. to treat osteoarthritis, acute pain conditions, and dysmenorrhoea...
however, which has since been withdrawn, had been shown to produce significantly fewer gastrointestinal ADRs compared with naproxen. This study, the VIGOR trial, raised the issue of the cardiovascular safety of the coxibs - a statistically insignificant increase in the incidence of myocardial infarction
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
s was observed in patients on rofecoxib. Further data, from the APPROVe trial, showed a statistically significant relative risk of cardiovascular events of 1.97 versus placebo - a result which resulted in the worldwide withdrawal of rofecoxib in October 2004.
COX-3 inhibitors
SimmonsDaniel L. Simmons
Daniel L. Simmons is a professor of chemistry and the director of the Cancer Research Center at Brigham Young University . He was the discoverer of the COX-2 enzyme that is the target of celecoxib and other COX-2 inhibitors...
also co-discovered COX-3
COX-3
COX-3 is an enzyme that is encoded by the PTGS1 gene, but is not functional in humans. COX-3 is the third and most recently discovered cyclooxygenase isozyme, the others being COX-1 and COX-2...
in 2002 and analyzed this new isozyme's relation to paracetamol
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...
(acetaminophen), arguably the most widely used analgesic drug in the world. The authors postulated that inhibition of COX-3 could represent a primary central mechanism by which these drugs decrease pain and possibly fever.
The relevance of this research has been called into question as the putative COX-3
COX-3
COX-3 is an enzyme that is encoded by the PTGS1 gene, but is not functional in humans. COX-3 is the third and most recently discovered cyclooxygenase isozyme, the others being COX-1 and COX-2...
gene encodes proteins with completely different amino acid sequences than COX-1 or COX-2. The expressed proteins do not show COX activity and it is unlikely that they play a role in prostaglandin mediated physiological responses.
Veterinary use
Research supports the use of NSAIDs for the control of pain associated with veterinary procedures such as dehorning and castration of calves. The best effect is obtained by combining a short-term local anesthetic such as lidocaineLidocaine
Lidocaine , Xylocaine, or lignocaine is a common local anesthetic and antiarrhythmic drug. Lidocaine is used topically to relieve itching, burning and pain from skin inflammations, injected as a dental anesthetic or as a local anesthetic for minor surgery.- History :Lidocaine, the first amino...
with an NSAID acting as a longer term analgesic. However, as different species have varying reactions to different medications in the NSAID family, little of the existing research data can be extrapolated to animal species other than the specific species studied, and the relevant government agency in one area will sometimes prohibit uses which are approved in other jurisdictions.
For example, ketoprofen
Ketoprofen
Ketoprofen, 2--propionic acid is one of the propionic acid class of non-steroidal anti-inflammatory drug with analgesic and antipyretic effects...
's effects have been studied in horses more than in ruminants but, due to controversy over its use in racehorses, veterinarians treating livestock in the United States more commonly prescribe flunixin meglumine
Flunixin Meglumine
Flunixin is a non-steroidal anti-inflammatory drug , analgesic, and antipyretic used in horses. It is often formulated as the meglumine salt. In the United States, it is regulated by the U.S...
, which while labeled for use in such animals is not indicated for post-operative pain.
In the United States, meloxicam
Meloxicam
Meloxicam is a nonsteroidal anti-inflammatory drug with analgesic and fever reducer effects. It is a derivative of oxicam, closely related to piroxicam, and falls in the enolic acid group of NSAIDs...
is approved for use only in canines, whereas (due to concerns about liver damage) it carries warnings against its use in cats except for one-time use during surgery. In spite of these warnings, meloxicam is frequently prescribed "off-label" for non-canine animals including cats and livestock species. In other countries (for example EU
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
and CAN
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
), by contrast, there is a label claim for use in cats.