Does H2-receptor antagonist alter the renal function of cyclosporine-treated kidney grafts?

Drug Interactions with Antiulcer Agents: Considerations in the Treatment of Acid-Peptic Disease

All of the antiulcer agents have been implicated in drug interactions. These agents generally influence the absorption, metabolism, or elimination of other medications. However, these interactions can lead to alterations in pharmacodynamic response. The mechanisms by which antiulcer agents produce drug interactions differ among the agents. It is beyond the scope of this article to review all of the drug interactions that have been reported with antiulcer agents. However, it is the intent to provide the reader with a detailed understanding of the mechanisms by which antiulcer agents may interact with other medications and to provide insight into factors that may influence the potential magnitude or clinical consequences of these interactions. An understanding of antiulcer drug interactions will aid pharmacists in assisting clinicians with drug selection and/or monitoring of drug interactions. Specifically, pharmacists can assist with the identification of potential antiulcer drug interactions and develop strategies designed to minimize adverse consequences of these interactions.

Evaluation of the pharmacokinetic interaction between cimetidine or famotidine and cyclosporine in healthy men

OBJECTIVE

To investigate the potential interaction between cimetidine or famotidine and cyclosporine in healthy men.

DESIGN

All subjects received oral cyclosporine at baseline, after the first week of 1 histamine2 (H2)-blocker, and a third time after a 1-week washout plus 1 week of the second H2-blocker. Blood samples were collected just before each dose of cyclosporine and for up to 36 hours afterward for pharmacokinetic analysis.

SETTING

A college of pharmacy in a university teaching hospital.

PARTICIPANTS

The study population consisted of 8 healthy men at least 19 years of age.

MAIN OUTCOME MEASURES

Cyclosporine concentrations in whole blood were measured using a polyclonal fluorescence polarization immunoassay. Cyclosporine pharmacokinetic parameters during each of the 3 treatment periods were compared.

RESULTS

The average times to maximum cyclosporine concentrations were similar between baseline (3.2 h), cimetidine (2.9 h), and famotidine (3.6 h) dosing periods. There were no significant differences in area under the curve, half-life, or maximum concentration during the 3 dosing periods.

CONCLUSIONS

Neither cimetidine or famotidine produced a significant change in the pharmacokinetics of single-dose oral cyclosporine in healthy men.

Effect of famotidine on renal transplant patients treated with ciclosporine A

The influence of a 7-day course of 40 mg famotidine administered orally on the pharmacokinetics of ciclosporine A at steady-state has been investigated in 10 renal transplant patients. Famotidine did not appear to significantly alter the pharmacokinetics of ciclosporine A. This might be ascribed to the limited potential of famotidine for inhibiting microsomal enzyme function. Moreover, plasma creatinine concentrations and creatinine clearance remained stable. Our results suggest that famotidine has no noticeable interaction with ciclosporine A.