Suction
After taking the drug inside desloratadine is well absorbed from the gastrointestinal tract (GIT), while the determined concentrations of desloratadine in blood plasma are reached within 30 minutes. After a single dose of 5 mg or 7.5 mg, the maximum concentration (FROMmOh) is reached after approximately 3 hours (2-6 hours). Bioavailability of desloratadine is proportional to the dose (in the dose range of 5-20 mg).
Distribution
The binding of desloratadine to plasma proteins is 83-87%, and 3-hydroxydeslorotodine 85-89%. When applied at a dose of 5 mg to 20 mg 1 time / day for 14 days, no signs of clinically significant cumulation of desloratadine were detected. Simultaneous food intake or simultaneous use of grapefruit juice does not affect the bioavailability and distribution of desloratadine (when taken at a dose of 7.5 mg 1 time / day). Does not penetrate the blood-brain barrier (BBB).
Metabolism and excretion
It is subjected to intensive metabolism in the liver to 3-hydroxydesoratodine, which is then glucuronized. The main way of metabolism of desloratadine is hydroxylation. Is not an inhibitor of isoenzymes CYP3A4 and CYP2D6 and is not a substrate or inhibitor of P-glycoprotein. Desloratadine is excreted from the body in the form of a glucuronide compound and in a small amount in unchanged form (kidneys less than 2% and through the intestine - less than 7%). The half-life for both desloratadine and 3-hydroxydesoratodine is 20-30 hours (on average - 27 hours).
Chronic renal failure (CRF)
FROMmOh and the area under the "concentration-time" curve (AUC) desloratadine increase from 1.2 to 1.7 times and from 1.9 to 2.5 times, respectively (compared with the data in healthy volunteers). The concentration of 3-hydroxydeslorotodine varies insignificantly. The binding of desloratadine and 3-hydroxydeslorotodine with plasma proteins in chronic renal failure does not change. Desloratadine and 3-hydroxydesloratodine are poorly excreted in hemodialysis.
Liver failure
Have patients with hepatic insufficiency AUC increases by 2.4 times compared with the data in healthy volunteers.The total clearance of desloratadine for oral administration in patients with mild, moderate and severe hepatic insufficiency is 37%, 36% and 28% respectively (in comparison with the data of healthy volunteers). There is an increase in the half-life of desloratadine in patients with hepatic insufficiency.
FROMmOh and AUC 3-hydroxydesloratodine in patients with hepatic insufficiency do not differ from the data in healthy people with normal liver function.