Omeprazole: A Study of Its Inhibition of Gastric pH and Oral Pharmacokinetics After Morning or Evening Dosage
1985; Elsevier BV; Volume: 88; Issue: 1 Linguagem: Inglês
10.1016/s0016-5085(85)80133-5
ISSN1528-0012
AutoresPeter J Prichard, Neville D. Yeomans, George W. Mihaly, D B Jones, P. J. Buckle, Richard A. Smallwood, William J. Louis,
Tópico(s)Ion Transport and Channel Regulation
ResumoPharmacodynamic and pharmacokinetic studies of omeprazole, a new gastric antisecretory agent, were undertaken in 8 healthy subjects.The drug was administered orally as an encapsulated entericcoated granulate (40 mg daily at 9 AM or 9 PM for 5 days), and its effect on the integrated 24-h gastric pH was determined, together with its apparent bioavailability.The pretreatment 24-h median pH was 1.9 (interquartile range 1.4-2.9).After 5 days of treatment, the median pH had risen to 5.0 (3.7-6.0) (p < 0.01) with morning dosage and 4.5 (3.0-5.6)(p < 0.01) with evening dosage .This corresponded to a > 99% reduction in 24-h median hydrogen ion activity, with morning dosage having a greater effect (from 9 AM to 8 PM) (p < 0.01) than evening dosage.The relative bioavailability of omeprazole increased twofold from day 1 to day 5 of treatment with morning dosage (p < 0.02) and threefold with evening dosage (p < 0 .02),suggesting that increased absorption of this acid-labile drug occurs with increasing inhibition of acid secretion.We conclude that this formulation of omeprazole presently being used in clinical trials is a highly potent antisecretory
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