Celebrex works fast in the body with max plasma concentration reached within 3 hours post oral dose. In prolonged treatment with multiple doses of the medicine during a certain period of time, the steady – state condition is obtained on the 5th day of treatment.
The food does have the effect on the absorption of the medicine. It is delayed up to 2 hours. Still the increase in total absorption up to 20% is observed when the drug is administered with food. In trial participants who used the medicine without food, there was less than a proportional increase in Cmax and total absorption of Celebrex (in dose of 200 mg). This is supposed to be linked with low solubility of celecoxib in the water environment.
When the medicine was administered with aluminum- and magnesium-containing antacids, the 37% reduction of celecoxib levels in plasma was observed. The decrease in total absorption up to 10% was detected under the same conditions.
According to the trials’ findings Celebrex doses up to 200 mg used twice daily should be administered without regard to timing of meals. Celebrex doses up to 400 mg twice daily should be administered with food to enhance absorption.
Celebrex is extensively distributed in the body tissues. The medicine is highly protein bound (about 97%) within the therapeutic dose limits. In lab studies celecoxib was detected to connect mostly to albumin.
The metabolic transformation of the medicine is primarily regulated through CYP2C9. The medicine in its unchanged form (less than 3%) and its metabolites are eliminated mainly by hepatic metabolism. About 57% of the dose is excreted in the feces and 27% is excreted into the urine.