Ranitidine nephrotoxicity

Cimetidine may increase cyclosporine levels and cause nephrotoxicity. Famotidine, Ranitidine, and cimetidine are now available over the counter. 

The nephrotoxicity of dsplatin is reduced in humans [132], mice [133] and dogs [134] by co-admin-istration of probenecid, suggesting that cisplatin is transported by the PAH transport system. It has been proposed that platinum, hke other nephrotoxic metal ions such as mercury and potassium dichromate, are taken up by tubular cells as sulphydryl conjugate through a probenecid-sensitive pathway [133]. However, cisplatin might also be transported by the organic cation transport system, since quinidine, cimetidine and ranitidine inhibited its net secretion flux in the dog kidney [134]. 

Reports are inconsistent. Cimetidine and famotidine have been reported to increase cielosporin levels, whereas in other studies cimetidine, famotidine and ranitidine have been reported to not affect cielosporin levels. Both cimetidine and ranitidine have been reported to cause an increase in serum creatinine levels, in some but not all studies, but this may possibly not be a reliable indicator of increased nephrotoxicity. Isolated cases of thrombocytopenia and hepatotoxicity have been reported with ranitidine and cielosporin. 

Information about the possible interactions of ciclosporin and cimetidine, famotidine or ranitidine is inconsistent, but there appear to be very few reports of confirmed toxicity. Moreover the reported increases in serum creatinine levels seen with the H2-receptor antagonists may not be a reflection of increased nephrotoxicity (see Mechanism )- Thus there is little to suggest that concurrent use should be avoided, but good initial monitoring is advisable. 

A newer combination of ranitidine and bismuth subcitrate with two antibiotics has also been introduced and approved for eradication. It is claimed that this form of bismuth is more soluble and more available for bactericidal action. However, significant blood levels of bismuth have been detected in some patients, and this cation is neurotoxic and nephrotoxic. Most of the data reported have not used intention-to-treat criteria, and the general impression is that eradication is less effective. Another issue is that after eradication therapy, treatment with ranitidine is continued for the routine period of 8 weeks rather than the 4 weeks for a PPI. 

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