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J Drug Assess. 2014 Feb 17;3(1):20-7. doi: 10.3109/21556660.2014.895371. eCollection 2014.

Pharmacodynamic evaluation of intragastric pH and implications for famotidine dosing in the prophylaxis of non-steroidal anti-inflammatory drug induced gastropathy-a proof of concept analysis.

Journal of drug assessment

Jeffery D Kent, Robert J Holt, Donald Jung, George F Tidmarsh, Amy Y Grahn, Julie Ball, David A Peura

Affiliations

  1. Horizon Pharma, Inc, Deerfield, ILUSA.
  2. University of Illinois-Chicago, ILUSA.
  3. Pharmaceutical Research Services, Inc, Cupertino, CAUSA.
  4. Stanford University School of Medicine, Stanford, CAUSA.
  5. University of Virginia Health Sciences Center, Charlottesville, VAUSA.

PMID: 27536450 PMCID: PMC4937634 DOI: 10.3109/21556660.2014.895371

Abstract

OBJECTIVE: Famotidine given at a dose of 80 mg/day is effective in preventing NSAID-induced gastropathy. The aim of this proof of concept study was to compare twice a day (BID) vs 3-times a day (TID) administration of this total dose of famotidine on intragastric pH in healthy volunteers.

RESEARCH DESIGN AND METHODS: Two analyses were undertaken: (1) a 13 subject controlled cross-over 24-h intragastric pH evaluation of the BID and TID administration of 80 mg/day of famotidine, as well as measures for drug accumulation over 5 days (EudraCT, number 2006-002930-39); and (2) a pharmacokinetic (PK)/pharmacodynamic (PD) model which predicted steady-state famotidine plasma concentrations and pH of the two regimens.

RESULTS: For the cross-over study, gastric pH was above 3.5 for a mean of 20 min longer for TID dosing compared to BID dosing on Day 1. On Day 5, the mean time above this threshold was higher with the BID regimen by ∼25 min. For pH 4, subjects' gastric pH was above this pH value for a mean of 25 min longer for TID dosing compared to BID dosing on Day 1. For Day 5, the pH was above 4 for ∼45 min longer with the TID regimen as compared with the BID regimen. The mean 24-h gastric pH values when taken in the upright position trended higher for the TID dosing period compared to the BID regimen on Day 1. The steady-state simulation model indicated that, following TID dosing, intragastric pH will be above 3 for 24 h vs 16 h for the BID regimen. There was no evidence for plasma accumulation of famotidine with TID dosing as compared to BID dosing from either analysis.

CONCLUSION: The data indicate that overall more time is spent above the acidic threshold pH values when 80 mg/day of famotidine is administered TID vs BID. Key limitations included small study size with a short duration and lack of a baseline examination, but was compensated for by the cross-over and PK/PD modeling design. Although most of the comparisons in this proof of concept study were not statistically significant these results have important implications for future research on gastric acid lowering agents used for the prevention of NSAID-induced gastropathy.

Keywords: Famotidine; Gastropathy; Intragastric; NSAID; Prophylaxis; pH

References

  1. Curr Med Res Opin. 2011 Jun;27(6):1243-53 - PubMed
  2. South Med J. 2012 Nov;105(11):613-8 - PubMed
  3. Am J Med. 1998 Mar 30;104(3A):56S-61S; discussion 79S-80S - PubMed
  4. Expert Rev Gastroenterol Hepatol. 2012 Feb;6(1):25-35 - PubMed
  5. Eur J Clin Pharmacol. 1996;50(6):449-56 - PubMed
  6. JAMA. 2000 Sep 13;284(10):1247-55 - PubMed
  7. J Clin Pharmacol. 2011 Jul;51(7):1079-86 - PubMed
  8. Am J Gastroenterol. 2012 Mar;107(3):379-86 - PubMed
  9. Arthritis Rheum. 2003 Aug 15;49(4):508-18 - PubMed
  10. Turk J Gastroenterol. 2005 Sep;16(3):138-42 - PubMed
  11. Gastroenterology. 1990 Aug;99(2):345-51 - PubMed
  12. N Engl J Med. 1996 May 30;334(22):1435-9 - PubMed
  13. Aliment Pharmacol Ther. 2010 Aug;32(3):414-24 - PubMed
  14. Curr Med Res Opin. 2009 Mar;25(3):729-40 - PubMed
  15. Clin Exp Pharmacol Physiol. 1996 May;23(5):432-4 - PubMed
  16. Clin Pharmacol Ther. 1988 Dec;44(6):690-8 - PubMed
  17. Am J Med. 1986 Oct 24;81(4B):3-7 - PubMed
  18. Arthritis Rheum. 2010 Jun;62(6):1592-601 - PubMed
  19. Pharmacoepidemiol Drug Saf. 2011 Jul;20(7):763-71 - PubMed
  20. Aliment Pharmacol Ther. 2007 Jan 1;25(1):103-9 - PubMed
  21. Arthritis Res Ther. 2013;15 Suppl 3:S3 - PubMed

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