The true cost of monitoring antibiotic levels.

Antibiotic assays are most often ordered for the purpose of toxicity monitoring, which usually involves determination of peak and trough antibiotic concentrations in the blood. The cost of monitoring antibiotic levels is probably higher than is commonly appreciated. Factors that contribute to the cost of this service include staffing the microbiology laboratory with appropriate personnel, who are responsible for determining the adequacy of sample collection and related patient information; analyzing the specimens in a timely manner; and taking action to modify drug dosage and dosage intervals in light of the test results. There are also costs related to the reagents, consumables, and equipment used in the assay, as well as to revenue and capital overheads. Additional clinical and laboratory costs can be incurred in the event of litigation pursuant to antibiotic-induced toxicity. With hospital and government policymakers devoting increasing attention to the escalating costs of health care, pressure to move away from the routine use of drugs having dose-related toxicity may increase, the objective being to save on assay costs.