Carbenicillin inactivation of aminoglycosides in patients with severe renal failure.

Carbenicillin appears to produce clinically important inactivation of aminoglycoside antibiotics in patients with severe renal failure. If combination carbenicillin/aminoglycoside therapy is used in patients with severe renal failure, the dose of carbenicillin must be adjusted to renal function and serum levels of both drugs should be monitored. Even with therapeutic serum carbenicillin levels (100-200 mug/ml), large doses of aminoglycosides may be required to achieve therapeutic serum levels and this may increase the risk of toxicity.