Therapeutic-Interchange Programs: Potential Consequences of Automatic Conversion of Cimetidine to Another H 2 -Antagonist

Abstract

The goal of this study was to determine—through an evaluation of the literature—if other H₂-receptor antagonists work as well as cimetidine to improve the accuracy and precision of glomerular filtration rate (GFR) measurements following an automatic therapeutic interchange. A PubMed query was conducted for articles (published in the past 10 years) related to creatinine clearance, glomerular filtration rate (GFR), H₂-receptor antagonists, and the H₂-antagonist drugs. References from these articles were then reviewed to identify further sources. It was found that ranitidine and famotidine do not significantly inhibit tubular creatinine secretion and therefore have no effects on plasma creatinine or creatinine clearance. The literature search failed to provide information on nizatidine's effect on creatinine or creatinine clearance. Cimetidine appears to be the only H₂-receptor antagonist with the ability to improve the accuracy and precision of GFR measurements. These conclusions imply that non-FDA approved uses must also be considered when designing and implementing therapeutic interchange programs.