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mon enzymes expressed in almost all the tissues and blood platelets. It is mainly involve in keeping the internal environment of tissue constant and production prostaglandin. There are certain other function associated with it, which involves gastric cytoprotection, platelets aggregation, renal blood flow auto regulation and the initiation of parturition.
On the other hand COX-2 enzymes are involved in inflammatory cells, this is where they synthesised and activated. This is why COX-2 enzymes are main source of production of prostanoid mediator of significant exceptions. There is a large amount of COX-2 could be found in central nervous system (CNS) and some other tissues.

All the NSAIDs perform their function by inhibiting the COX enzymes but each NSAID enzyme has its own different pathway of action. The basic Anti-inflammatory action of NSAIDs is caused by inhibition of COX-2 enzyme and the unwanted effects mainly those affecting the gastrointestinal tract are mostly caused by action of their inhibition of COX-1. The compounds which only inhibit the COX-2 enzyme are now clinically available but due to increase in cardiovascular risk the treatment of inflammatory conditions have received a setback.

 

Pharmacokinetics

Mostly non-steroidal anti-inflammatory drugs are weakly acidic, they have a pKa of 3-5. This is one of the main reasons that they absorb well in thestomach wallsand intestinal mucosa. They have high tendency to form bonds with proteins in plasma therefore their volume of distribution is similar to plasma volume. NSAIDs are mostly metabolised in liver by oxidation and conjunction to inactive metabolites which are then excreted from urine, even some drugs excreted inbile. Metabolism could be abnormal in some disease states and cause accumulation with normal dosage.

Some of the NSAIDs have very short half- life from two to three hours i.e. Ibuprofen where as other may have very long half-life up to 60 days

 

ASPIRIN

Aspirin which is also called acetylsalicylic acid is one of the most commonly used drugs. Aspirin has very good anti-inflammatory, antipyretic and antiplatelet properties. Aspirin is batter then other NSAIDs in its action as it acts as a non competitive inhibitor for enzymes COX where as other NSAIDs act as competitive inhibitors. Aspirin was first extracted from willow bark in the form of salicylic acid, which was later altered to form aspirin. Salicylic acid has same functions as aspirin but it doesn't form platelets in blood when needed. Today aspirin is available in different dosage forms i-e tablets, syrups and dissolve able powders.

Aspirin is weakly acidic therefore it could take directly from mouth and easily absorbed in stomach walls and have systematic effects. If aspirin is taken in, when stomach is full it will mix up with stomach content and absorbed more rapidly. https://www.51lunwen.org/dxygassignment/ However if aspirin is taken with empty stomach it might cause gastric erosions. In small intestine aspirin has lipophobic properties but due to large surface area of ileum, it absorb readily this is why aspirin absorption is relatively fast in intestine.

Therapeutic uses

Headache

Aspirin is one of the main drugs used for treatment of migraine, it is equally effective as other drugs such as paracitamol and ibuprofen but it is associated with its own gastrointestinal side effects. It is said that aspirin and parac本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。