Lack of inhibitory effect of cimetidine on caffeine metabolism in children using the caffeine breath test

Abstract

Aims To study the potential drug interaction between cimetidine and caffeine in a group of children who received cimetidine for gastritis.

Methods The caffeine breath test was carried out prior to the administration of cimetidine and after 2–3 weeks therapy. The children (n=1) received 300–800 mg cimetidine daily (11–36 mg kg−1 day−1 ).

Results There was no significant change in the 2 h cumulative labelled CO2 following the administration of cimetidine (mean values 5.61% before and 4.87% during cimetidine; Student’s t-test P>0.2).

Conclusions Cimetidine did not have an inhibitory effect on the metabolism of caffeine in this group of children studied.