Interaction Studies of Cephradine with Hh-Receptor Antagonist

Cephradine, a first generation semisynthetic cephalosporin antibiotic, is widely used in clinics for its activity against both Gram-positive and Gram-negative bacteria. It is indicated for the treatment of urinary tract infections, skin and skin structure infections, respiratory tract infections, and otitis media. Interactions of cephradine with H2-receptor antagonists (cimetidine, ranitidine and famotidine) were investigated by UV/visible spectrophotometer in simulated gastric juice (pH 1) and blood pH (pH 7.4) at body and elevated temperatures. The availability of cephradine at 37 °C in both media was increased to 102 and 105 % when interacted with cimetidine, while at elevated temperatures the availability of cephradine was increased only in simulated gastric juice. It was observed that at 37 °C cephradine availability increased in presence of ranitidine only in buffer of pH 7.4 whereas at 48 °C no remarkable change was observed. However, at 60 °C the availability of cephradine increased to 115 % in both media. In presence of famotidine, at 37 °C it was observed that % availability of cephradine increased only in simulated gastric juice. However, at higher temperature, results similar to cimetidine were observed. Hence forth, it was concluded on the basis of the above results that cephradine and H2-receptor antagonists affect each other s availability and may decrease activity, in vitro as well as in vivo.