Trimethoprim, metioprim, tetroxoprim, and RO 10-5970 in canine bone

The penetration of trimethoprim and three derivatives into bone tissue was investigated in a dog model. Our data demonstrated that the trimethoprim derivative RO 10-5970 concentrates well in bone tissue with median tissue-to-serum concentration ratios of 0.23 in cortical bone and 0.81 in both medulla and cancellous bone. The use of RO 10-5970 in osseous infections is appealing because oral administration is possible; therefore, clinical trials appear warranted.