What is the pharmacokinetics of aspirin?
Pharmacology/Pharmacokinetics Aspirin is rapidly absorbed in the upper gastrointestinal (GI) tract and results in a measurable inhibition of platelet function within 60 minutes. This antiplatelet effect is associated with prolongation of the bleeding time and inhibition of TXA2-dependent platelet aggregation.
What affects pharmacokinetics of aspirin?
Absorbed aspirin is rapidly hydrolyzed systemically. Salicylic acid elimination kinetics are dependent on drug concentration due to the limited capacity of two major biotransformation pathways: formation of salicyluric acid and of salicylphenolic glucuronide.
Does aspirin follow first order kinetics?
From the above equation, it can be seen that the degradation of aspirin in a solution buffered at pH = 7.5 will follow first order kinetics; that is, the reaction will appear to be a first order reaction, dependent only on the concentration of one reactant; i.e. aspirin.
How is aspirin metabolised and excreted?
Aspirin undergoes phase 1 hydrolysis to salicylic acid. In phase 2 it is congugated with either glycine or glucoronic acid forming a range of ionised metabolytes that can then be excreted in the urine.
What is meant by the term pharmacokinetics?
(FAR-muh-koh-kih-NEH-tix) The activity of drugs in the body over a period of time, including the processes by which drugs are absorbed, distributed in the body, localized in the tissues, and excreted.
Which is metabolic pathway of aspirin *?
Salicylate is mainly metabolized in the liver, although other tissues may also be involved in this process Label. The major metabolites of acetylsalicylic acid are salicylic acid, salicyluric acid, the ether or phenolic glucuronide and the ester or acyl glucuronide.
How does aspirin affect the bleeding time?
Aspirin influences the bleeding time, presumably through the inhibition of prostaglandin biosynthesis and the resultant platelet secretion reaction. This can be measured by prolongation of the bleeding time and changes in platelet function results.
Is aspirin first or zero order kinetics?
aspirin equivalent, conjugation of salicylic acid with glycine reached a maximum rate and thus proceeded by zero-order kinetics.
Is the hydrolysis of aspirin first order?
The equation for its hydrolysis to salicylic and acetic acids may be written very simply. It can be shown that the hydrolysis of aspirin is pseudo-first order under the conditions used.
How is aspirin digested?
Aspirins absorption is pH sensitive at the level of the small intestine. Absorption is higher through the small intestine than the stomach for the same pH range. At pH 3.5 or 6.5, aspirin’s intestinal absorption is greater than the gastric absorption of the compound. The stomach does not absorb aspirin at pH 6.5.
Is aspirin rapidly metabolized?
It is rapidly hydrolyzed in the body to salicylic acid; the plasma concentration of the latter must be maintained within a relatively narrow range to obtain an adequate anti-inflammatory effect and to minimize systemic adverse effects.