Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1 Pharmacodynamic properties
Pharmacotherapeutic Group: Anti-inflammatory and anti-rheumatic products, non- steroids, propionic acid derivatives.

ATC Code: M01AE01
Ibuprofen is a propionic acid derivative, having analgesic, anti-inflammatory and antipyretic activity.
The drug's therapeutic effects as a non-steroidal anti- inflammatory are thought to result from inhibitory activity on prostaglandin synthetase. Furthermore, ibuprofen reversibly inhibits platelet aggregation.
Experimental data suggest that ibuprofen may competitively inhibit the effect of low dose acetylsalicylic acid on platelets aggregation when they are dosed concomitantly. Some pharmacodynamics studies show that, when single doses of ibuprofen 400mg was taken within 8 h before or within 30 min after immediate release acetylsalicylic acid dosing (81mg), a decreased effect of acetylsalicylic acid on the formation of thromboxane or platelet aggregation occurred. Although there are uncertainties regarding extrapolation of these data to the clinical situation , the possibility that regular , long-term use of ibuprofen may reduce the cardioprotective effect of low-dose acetylsalicylic acid cannot be excluded. No clinically relevant effect is considered to be likely for occasional ibuprofen use. (see section 4.5).

Product specific pharmacodynamics properties:
Ibuprofen is dissolved in a hydrophilic solvent inside a gelatin shell. On ingestion, the gelatin shell disintegrates in the gastric juice releasing the solubilized ibuprofen for absorption.

Pharmacokinetic Properties

5.2 Pharmacokinetic properties
The ibuprofen from Nurofen Liquid Capsules is absorbed to the same extent as ibuprofen from Nurofen tablets, the AUC0-a_ being equivalent. Ibuprofen is rapidly absorbed from Nurofen Liquid Capsules with maximum plasma concentration achieved in 30 minutes. In comparison, the maximum plasma concentration of Nurofen tablets is achieved in 90 minutes. When taken with food, plasma peak levels may be delayed.

Ibuprofen is rapidly absorbed following administration and is rapidly distributed throughout the whole body. Ibuprofen diffuses into the synovial fluid. The excretion is rapid and complete via the kidneys.

Peak plasma concentration of ibuprofen occurs 1-2 hours after administration of ibuprofen acid.
When taken with food, peak plasma levels may be delayed. These times may vary with different dosage forms.

Elimination half life is approximately 2 hours.

Following hepatic metabolism (hydroxylation, carboxylation, conjugation), the pharmacologically inactive metabolites are completely eliminated, mainly renally (90%), but also with the bile. The elimination half-life in healthy individuals and those with liver and kidney diseases is 1.8 to 3.5 hours.
Plasma-protein binding is about 99%.
No significant differences in pharmacokinetic profile are observed in the elderly.