Prilosec - Clinical Pharmacology

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Oral Dosing /Parameter

Children * < 20 kg

2-5 years 10 mg

Children * > 20 kg

6-16 years 20 mg

Adults * (mean 76 kg)

23-29 years (n= 12)

Single Dosing Cmax*

(ng/ mL) 288 (n= 10) 495 (n= 49) 668 AUC*

(ng h/ mL) 511 (n= 7) 1140 (n= 32) 1220 Repeated Dosing

Cmax* (ng/ mL) 539 (n= 4) 851 (n= 32) 1458

AUC* (ng h/ mL) 1179 (n= 2) 2276 (n= 23) 3352

Note: * = plasma concentration adjusted to an oral dose of 1 mg/ kg. *

Data from single and repeated dose studies * Data from a single and repeated dose study

Doses of 10, 20 and 40 mg Omeprazole as Enteric-Coated Granules

Following comparable mg/ kg doses of omeprazole, younger children (2-5 years) have lower AUCs than children 6 – 16 years or adults; AUCs of the

latter two groups did not differ. (See DOSAGE AND ADMINISTRATION – Pediatric Patients.)

Pharmacokinetics:

Combination Therapy with Antimicrobials

Omeprazole 40 mg daily was given in combination with clarithromycin 500 mg every 8 hours to healthy adult male subjects. The steady state plasma concentrations of omeprazole were increased (Cmax, AUC0-24, and T1/ 2 increases of 30%, 89% and 34% respectively) by the concomitant administration of clarithromycin. The observed increases in omeprazole plasma concentration were associated with the following pharmacological effects. The mean 24-hour gastric pH value was 5.2 when omeprazole was administered alone and 5.7 when co-administered with clarithromycin. The plasma levels of clarithromycin and 14-hydroxy-clarithromycin were increased by the concomitant administration of omeprazole.

For clarithromycin, the mean Cmax was 10% greater, the mean Cmin was 27% greater, and the mean AUC0-8 was 15% greater when clarithromycin was administered with omeprazole than when clarithromycin was administered alone. Similar results were seen for 14-hydroxy-clarithromycin, the mean Cmax was 45% greater, the mean Cmin was 57% greater, and the mean AUC0-8 was 45% greater. Clarithromycin concentrations in the gastric tissue and mucus were also increased by concomitant administration of omeprazole.