Inattention to the pharmacokinetic properties of antibiotics in each individual host can be disastrous or, if you are lucky, go unnoticed. This is the essence of Dr Pieroni's letter.
Our study published in the Archives—though a review of 20 cases-attempts to point out to the reader the risk of leukopenia in adults treated with penicillin and cephalosporin homologues in a dosage of 150 mg/ kg/day or more for longer than two weeks. Awareness of this dosage limitation will require the clinician to calculate dosage based on the adult patients' weight rather than blindly administer the same dosage to all.
Dr Pieroni carries the argument further and extends our approach to aminoglycoside antibiotics, with the caveat that aging considerations introduce another variable. His concerns have been well documented in the medical literature.1-4 We cannot agree more. In addition, measurement of aminoglycoside peak and trough levels will act as