Piperacillin plus amikacin therapy v carbenicillin plus amikacin therapy in febrile, granulocytopenic patients.

In a prospective randomized trial, febrile, granulocytopenic patients received either piperacillin sodium plus amikacin sulfate or carbenicillin disodium plus amikacin as initial empiric antimicrobial therapy. Although significantly more gram-negative aerobic bacilli isolated from initial cultures were susceptible to piperacillin than to carbenicillin (54 of 58 v 30 of 58), the overall response rates for the two regimens were similar (113 of 143 or 79% for piperacillin plus amikacin and 116 of 154 or 75% for carbenicillin plus amikacin). Piperacillin plus amikacin was associated with less hypokalemia (26 of 143 v 56 of 154). Nephrotoxicity, which was minimal with both regimens, developed less frequently in patients receiving carbenicillin plus amikacin (12 of 143 v two of 154). These results suggest that the overall efficacy of piperacillin plus amikacin is similar to carbenicillin plus amikacin and that piperacillin plus amikacin may be associated with less hypokalemia but more nephrotoxicity.