Bacampicillin, Ampicillin, Cephalothin, and Cephapirin levels in human blood and interstitial fluid.

The diffusibility of bacampicillin, ampicillin, cephalothin, and cephapirin into human interstitial fluid was investigated by using crossover studies. We compared bacampicillin with ampicillin and found that bacampicillin was better absorbed after oral administration. Blood, interstitial fluid, and urine levels were consistently higher in volunteers who received bacampicillin. We compared cephalothin with cephapirin and found that blood and interstitial fluid levels were comparable throughout the study.