What are 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.
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.
What are the pharmacokinetics of salicylates?
Aspirin absorption follows first-order kinetics with an absorption half-life ranging from 5 to 16 minutes. Hydrolysis of aspirin to salicylic acid by nonspecific esterases occurs in the liver and, to a lesser extent, the stomach so that only 68% of the dose reaches the systemic circulation as aspirin.
How is aspirin metabolised in the body?
As much as 80% of therapeutic doses of salicylic acid is metabolized in the liver. Conjugation with glycine forms salicyluric acid, and with glucuronic acid to form two different glucuronide esters.
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.
Is aspirin first order or zero order kinetics?
aspirin equivalent, conjugation of salicylic acid with glycine reached a maximum rate and thus proceeded by zero-order kinetics. The over-all elimination of salicylate was found to proceed by first-order kinetics at very small doses, and by parallel zero and first-order processes at higher doses.
Which drugs follow first order kinetics?
Examples are Ethanol, Phenytoin, Salicylates, Cisplatin, Fluoxetin, Omeprazol….
| Elimination kinetics | First order | Zero order |
|---|---|---|
| Term in clinical pharmacology | Linear kinetics | Non linear kinetics |
| Concerns | 95 % of drugs, at therapeutic concentrations | The remaining 5 %, and ethanol |
How long does it take for aspirin to metabolize?
It takes about 48 hours to excrete an aspirin completely. The half-life of aspirin in the blood stream is 13-19 minutes and the half-life of its metabolite salicylate is around 3.5-4.5 hours.