What is the meaning of COX-2?
Cox-2: Cyclooxygenase-2, an enzyme that acts to speed up the production of certain chemical messengers, called prostaglandins that play a key role in in promoting inflammation. When cox-2 activity is blocked, inflammation is reduced.
What is the meaning of COX-2 inhibitors?
COX-2 inhibitor refers to a relatively new class of non-steroidal anti-inflammatory drugs (NSAIDs) that targets the COX-2 enzyme specifically. These COX-2 inhibitors work by limiting the formation of inflammation, which is a common component of many forms of back pain and types of chronic pain.
What is the difference between COX-1 and COX-2?
In the gastrointestinal tract, COX-1 maintains the normal lining of the stomach and intestines, protecting the stomach from the digestive juices. 4 The enzyme is also involved in kidney and platelet function. COX-2, on the other hand, is primarily found at sites of inflammation.
What are COX-2 selective drugs?
COX-2 Selective (includes Bextra, Celebrex, and Vioxx) and Non-Selective Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
Is aspirin 1 or 2 COX?
Aspirin inhibits COX-1 (cyclooxygenase-1). Its effect on COX-2 is more delicate: it "turns off" COX-2's production of prostaglandins but "switches on" the enzyme's ability to produce novel protective lipid mediators. Aspirin is a widely used non-steroidal anti-inflammatory drug (NSAID).14-Jul-2009
What means COX?
The definition of cox, short for coxswain, means the person in charge of a boat or its crew. An example of a cox is the person directing rowers in a racing boat. noun.
Are COX-2 inhibitors still on the market?
Celecoxib is the only COX-2 inhibitor currently available in the United States. Rofecoxib (Vioxx) and valdecoxib (Bextra) are no longer available because they increased the risk of heart attacks and strokes with long term use. Rofecoxib was discontinued in 2004 and valdecoxib was discontinued in 2005.
Where are COX-1 and 2 located?
COX-1 was found in blood vessels, interstitial cells, smooth muscle cells, platelets and mesothelial cells. In contrast, COX-2 was found predominantly in the parenchymal cells of many tissues, with few exceptions, for example the heart.
Is ibuprofen COX-1 or 2?
Some NSAIDs (eg, flurbiprofen, ketoprofen) were COX-1 selective, some (eg, ibuprofen, naproxen) were essentially nonselective, while others (eg, diclofenac, mefenamic acid) were COX-2 selective.
How does COX-2 cause inflammation?
COX-2 inhibitors are NSAIDs that selectively block the COX-2 enzyme and not the COX-1 enzyme. Blocking this enzyme impedes the production of prostaglandins by the COX-2 which is more often the cause the pain and swelling of inflammation and other painful conditions.
Is diclofenac COX-2 selective?
Diclofenac is a selective COX-1 and COX-2 inhibitor. The reason why we used this drug in this study was that diclofenac was a widely used non-steroidal anti-inflammatory drug and topical diclofenac was available.05-Jan-2013
What enzyme is responsible for promoting inflammation?
See additional information. Cox-2: Cyclooxygenase-2, an enzyme that acts to speed up the production of certain chemical messengers, called prostaglandins that play a key role in in promoting inflammation. When cox-2 activity is blocked, inflammation is reduced.
What happens when Cox-2 is blocked?
When cox-2 activity is blocked, inflammation is reduced. Unlike cox-1, cox-2 is active only at the site of inflammation, not in the stomach.
What is the role of COX-2 in cancer?
COX-2 is another molecular target that has been shown to have significance in cancer development and progression. Selective inhibition of COX-2 has been shown to alter the development and progression of cancer in clinical trials. 117 In addition, inhibition of COX-2 activity results in enhanced radiosensitization of tumor tissue ...
Which isoform is responsible for the synthesis of the prostanoids involved in pathological processes?
COX-2 , expressed by cells that are involved in inflammation (e.g., macrophages, monocytes, synoviocytes), has emerged as the isoform that is primarily responsible for the synthesis of the prostanoids involved in pathological processes, such as acute and chronic inflammatory states. COX-2 can be up-regulated by various pro-inflammatory agents, including lipopolysaccharide, cytokines and growth factors. However, although COX-2 was initially regarded as a source of pathological prostanoids only, recent studies have indicated that this isoenzyme mediates a variety of physiological responses within the organism (e.g., ulcer healing, renal functions and cardiovascular protection) Hinz and Brune (2002).
Does COX-2 cause brain damage?
This observation indicates that COX-2 is also involved in the mechanisms of glutamate receptor–mediated brain damage, a process that occurs early in the ischemic cascade. 101,102. The downstream mechanisms by which COX-2 exerts its deleterious effects on the ischemic brain have recently been investigated.
What is the role of COX-2 in inflammation?
COX-2 has also been implicated in the mechanisms of postischemic inflammation. Cyclooxygenase, an integral membrane glycoprotein, is the rate-limiting enzyme for the synthesis of prostaglandins and thromboxanes from arachidonic acid. Although COX-1, a constitutive isoform, is expressed in virtually all cell types and produces physiologic levels of prostanoids,67 COX-2 is rapidly induced upon activation by mitogens, inflammatory mediators, and hormones.68 The catalytic activity of COX-2 is associated with the production of the free radical superoxide and prostanoids.68 Superoxide produced by COX-2 activity may react with NO to form the powerful oxidant peroxynitrite. Thus, increased COX-2 activity in inflammatory cells and neurons during acute and chronic inflammation may contribute to tissue damage through excessive generation of reactive oxygen species (ROS) and production of toxic prostanoids.
Is COX2 a target for stroke?
Taken together, the evidence from studies of pharmacologic inhibition and genetic disruption of COX-2 suggests that this enzyme is involved in both the initiation and progression of ischemic injury and may be a valuable target in the treatment of human stroke.
What is COX2 enzyme?
Cyclooxygenase, an integral membrane glycoprotein, is the rate-limiting enzyme for the synthesis of prostaglandins and thromboxanes from arachidonic acid.
Is COX-2 inhibitor safe for stroke patients?
However, the results of several clinical trials have revealed an increased incidence of vascular complications in patients receiving long-term treatment with COX-2 inhibitors, 109 indicating that long-term COX-2 inhibition may not be safe in stroke patients.
What are the rules for Cox-2?
The following rules have applied to all Cox-2 inhibitors that have been marketed: 1 Should not be used by patients who are allergic to sulfonamides 2 Should not be used by patients who have shown allergic reactions to other non-steroidal anti-inflammatory agents such as ibuprofen of naproxen. 3 Should not be used in patients who have aspirin-associated asthma. 4 The use of these drugs is specifically contraindicated in late pregnancy, since they may cause premature closure of the ductus arteriosus. 5 The Cox-2 inhibitors have not been studied in patients with advanced kidney disease, and their use is not recommended.
Why was Vioxx taken off the market?
Researchers noted the increase in fail-related injuries began in 2004, when the pain killer rofecoxib (Vioxx), a COX-2 inhibitor widely prescribed for arthritis pain, was taken off the market because of its link to a higher risk of heart attacks and strokes.
What is Cox-2 selective inhibitor?
The development of the Cox-2 selective inhibitors was intended to provide drugs that would offer the same pain relieving and anti-inflammatory effects as the traditional NSAIDs without causing the gastric ulcers that have been associated with the older drugs.
Is COX-2 an anti-inflammatory?
The principal benefit associated with selective COX-2 inhibitors is a production of comparable analgesia and anti-inflammatory effects to the nonselective NSAIDs, with fewer symptomatic gastric and duodenal ulcers and a decrease in gastrointestinal symptoms. Seizure following the Use of the COX-2 Inhibitor Etoricoxib.
What is the only Cox-2 inhibitor?
The only Cox-2 inhibitor on the market as of April 2005 is celecoxib (Celebrex). Celecoxib is indicated for treatment of rheumatoid and osteoarthritis, acute pain and the pain associated with primary dysmenorrhea. The drug is also used to reduce the number of polyps in familial adenomatous polyposis (FAP).
What is the term for a type of joint deterioration caused by damage to cartilage?
Osteoarthritis — A type of joint deterioration caused by damage to cartilage. Primary dysmenorrhea — Painful menstruation caused by inflammation, new growths, or anatomic factors. Proton pump inhibitor — One of a group of drugs that acts to reduce the secretion of stomach acid. Renal — Relating to the kidneys.
What are the functions of cyclooxygenases?
Prostaglandins act somewhat like hormones in controlling many of the functions of the body, including control of blood pressure and control of the smooth muscle of the respiratory tract and intestines. The traditional NSAIDs inhibit both cyclooxygenase 1 and 2 (Cox-1 and Cox-2).
What is the name of the enzyme that initiates the biotransformation of arachidonic acid to prostanoids
COX-1 and COX-2 in health and disease. Nearly 30 years ago, cyclooxygenase (COX) was identified as an enzyme that initiates the biotransformation of arachidonic acid to prostanoids. It is now known that COX exists as two distinct but similar isozymes, COX-1 and COX-2.
Is COX 1 the same as COX 2?
It is now known that COX exists as two distinct but similar isozymes, COX-1 and COX-2. Prostaglandins (PGs) formed by the enzymatic activity of COX-1 are primarily involved in the regulation of homeostatic functions throughout the body, whereas PGs formed by COX-2 primarily mediate pain and inflammation. Based on structural differences in the ...
What enzyme is responsible for the formation of prostaglandins?
Prostaglandins (PGs) formed by the enzymatic activity of COX-1 are pri …. Nearly 30 years ago, cyclooxygenase (COX) was identified as an enzyme that initiates the biotransformation of arachidonic acid to prostanoids. It is now known that COX exists as two distinct but similar isozymes, COX-1 and COX-2.
What is a COX-2 inhibitor?
COX-2 inhibitors are a type of nonsteroidal anti-inflammatory drug (NSAID) that directly targets cyclooxygenase-2, 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 drug class.
Does celecoxib inhibit COX-2?
The inhibition of COX-2 is paramount for the anti-inflammatory and analgesic function of the selective COX-2 inhibitor celecoxib. However, with regard to this drug's promise for the therapy of advanced cancers, it is unclear whether the inhibition of COX-2 plays a dominant role, and this has become a controversial and intensely researched issue. In recent years, several additional intracellular components (besides COX-2) were discovered that appear to be important for mediating the anticancer effects of celecoxib in the absence of COX-2. Moreover, a recent study with various malignant tumor cells showed that celecoxib could inhibit the growth of these cells, even though some of these cancer cells didn't even contain COX-2.
What was the Vioxx controversy?
VIGOR study and publishing controversy. The VIGOR (Vioxx Gastrointestinal Outcomes Research) trial, "which was the making of Merck's drug rofecoxib (Vioxx), " was at the center of a dispute about the ethics of medical journals.
How much did Pfizer pay in 2012?
A settlement was reached in April 2012 in which Pfizer agreed to pay $450 million. The other litigation is based on United States Pat. No. 6,048,850 owned by University of Rochester, which claimed a method to treat pain without causing gastro-intestinal distress by selectively inhibiting COX-2.
Which enzyme is responsible for synthesis of prostaglandins?
Prostaglandins whose synthesis involves the cyclooxygenase-I enzyme, or COX-1, are responsible for maintenance and protection of the gastrointestinal tract, while prostaglandins whose synthesis involves the cyclooxygenase-II enzyme , or COX-2, are responsible for inflammation and pain. The existing nonsteroidal anti-inflammatory drugs ( NSAIDs) ...
When did Vioxx get off the market?
Rofecoxib (sold under the brand name Vioxx) was taken off the market in 2004 because of these concerns, while celecoxib (sold under the brand name Celebrex) and traditional NSAIDs received boxed warnings on their labels. Many COX-2-specific inhibitors have been removed from the US market.
Who has sued Pfizer?
The basic research leading to the discovery of COX-2 inhibitors has been the subject of at least two lawsuits. Brigham Young University has sued Pfizer, alleging breach of contract from relations BYU had with the company at the time of Simmons's work.
What are COX inhibitors used for?
COX-2 inhibitors may be used to treat mild-to-moderate pain or inflammation caused by a wide range of conditions such as: 1 Ankylosing spondylitis 2 Hereditary polyps of the colon 3 Juvenile rheumatoid arthritis in children aged from two years 4 Menstruation 5 Osteoarthritis.
What is a Cox-2 inhibitor?
What are Cox-2 inhibitors? Cyclooxygenase-2 (COX-2) inhibitors are a type of nonsteroidal anti-inflammatory drug (NSAID) that specifically blocks COX-2 enzymes. Nonsteroidal anti-inflammatory agents (usually abbreviated to NSAIDs) are a group of medicines that relieve pain and fever and reduce inflammation.
What are the two types of COX enzymes?
There are two main types of COX enzymes: COX-1 and COX-2. Both types produce prostaglandins; however, the main function of COX -1 enzymes is to produce baseline levels of prostaglandins that activate platelets and protect the lining of the gastrointestinal tract, whereas COX -2 enzymes are responsible for releasing prostaglandins after infection ...
Do protaglandins inhibit COX-2?
Prostaglandins have several different effects, one of which is to regulate inflammation. By specifically only blocking COX-2 enzymes, COX-2 inhibitors relieve inflammation and pain with less adverse gastrointestinal effects than NSAIDs that inhibit both COX-1 and COX-2 enzymes. However, they are not devoid of gastrointestinal effects entirely, ...
What is COX-2 used for?
COX-2 inhibitors may be used to treat mild-to-moderate pain or inflammation caused by a wide range of conditions such as: Osteoarthritis. COX-2 inhibitors may also be used to treat acute pain such as that experienced with sports injuries.
Is Celecoxib a generic?
Celecoxib tends to be more expensive than nonselective NSAIDs; however, it is available as a generic. Celecoxib is considered as effective as other NSAIDs (such as ibuprofen, diclofenac, and naproxen) at reducing pain and inflammation, but the risk of gastrointestinal side effects is reduced. It is associated with a higher risk ...
Can Celebrex be used for stroke?
The risk increases the higher the dosage and the longer the duration of treatment. Celebrex should not be used in people with certain heart conditions, with a previous history of stroke, or after heart bypass surgery (coronary artery bypass graft, or CABG).