A solution of 0.5 g of imipenem (MK-0787) and 0.5 g of cilastatin sodium (MK-0791) in 100 ml of saline was administered to adult patients before the surgery by intravenous drip infusion during 30 minutes. Fifty samples of bone marrow blood were obtained from 26 clinical cases. After centrifugation, the supernatant was mixed with the same amount of a solution of stabilizer then stored at -80 degrees C. The peripheral blood was obtained at the same time as bone marrow blood was sampled and serum was served as control. The concentration of MK-0787 in bone marrow blood at 35 minutes after the start of the infusion was 50 micrograms/ml in 1 case, and decreased to 3.8 micrograms/ml at 260 minutes. The half-life was 1.62 hours. When the concentration of MK-0787 in bone marrow blood was compared to that in serum, the former was higher than the latter in 26 of the 50 samples (52%). In remained 24 samples, the concentration of MK-0787 in bone marrow blood showed to be lower than that in serum (48% of 50 samples). The half-life of MK-0791 in bone marrow blood was 1.10 hours and the level of the drug in bone marrow blood was similarly higher than that in serum in 18 of 40 samples (45%). In other 22 samples, the concentration of MK-0791 in bone marrow blood was lower than that in serum (55%). It was also found that the concentration of MK-0787 in bone marrow blood decreases with time along a similar curve of decrease observed in serum. This agent appears useful for the treatment of bone and joint infections and also for prophylaxis for major surgeries of skeletal tissues.