European Journal of Biomedical and Pharmaceutical Sciences

PHARMACOKINETIC INTERACTION BETWEEN ANTACID AND COMMONLY PRESCRIBED MEDICATIONS - METFORMIN, DICLOFENAC, AMOXICILLIN

Arjun Arumugam Olaganathan*, Ruckmani A, Geetha Lakshmi G, Arun Kumar R

ABSTRACT

Introduction: The self-prescribed use of antacids by ambulant patients may be ever increasing, because they are freely available over-the-counter and may commonly be taken along with various prescribed medications owing to the nature of comorbidities. It is important to understand their influence on pharmacokinetics of drugs. The influence may result in extreme clinical outcomes, ranging from treatment failure to toxicity. This study was, thus, conceived intending to study effect of antacids on pharmacokinetics of three commonly prescribed drugs. Methods: 18 consenting healthy human volunteers were recruited for study, 6 each to evaluate antacid’s effect on Amoxicillin, Diclofenac, Metformin, as per random in each treatment period. Clinical confinement and blood sampling was done as per ethics committee approved protocol following good clinical practice principles. The plasma samples were analyzed using validated LC-MS/MS bioanalytical method to quantify Amoxicillin, Diclofenac and Metformin in line with good laboratory practice principles. Pharmacokinetic and statistical evaluation of the results was conducted using WinNonlin. Results: The results showed variation in all pharmacokinetic parameters. It was observed that Cmax and AUC were reduced for all the three drugs when administered with antacid. The ANOVA results confirmed that bioavailability was incomparable, as the 90% CI for all three drugs did not fall within acceptable range of 80%-125%. Conclusion: It is observed that antacids influence pharmacokinetics of Amoxicillin, Diclofenac and Metformin by reducing their bioavailability. Further investigation is required to find clinical implications of these pharmacokinetic changes and to specifically understand influence of antacid on excipients used in drug products.

Keywords: Pharmacokinetic, Antacid, Diclofenac, Amoxicillin, Metformin, Bioavailability.