Inappropriate prescribing of aminoglycosides: risk factors and impact of an antibiotic control team

Objectives: Many factors are involved in the appropriate use of aminoglycosides, such as modalities of administration, drug levels monitoring and duration of treatment. We assessed prospectively the impact of an antibiotic control team on the appropriateness of prescriptions. Methods: After a first observational audit assessing the appropriateness of prescriptions, and issuing updated recommendations, we performed an interventional audit, where an antibiotic control team provided counselling when prescriptions were considered inappropriate. Appropriateness of prescriptions, clinical outcomes of patients and medical costs were compared between the two periods. Results: One hundred consecutive prescriptions were analysed in each period, and 32% of prescriptions were modified by the control team. As compared with the observational period, prescriptions in the intervention period were more appropriate with regard to treatment duration (73% versus 56%, P = 0.01) and drug levels monitoring (61% versus 40%, P = 0.05), and the median treatment duration was shorter (4 versus 6 days, P = 0.0002). Independent factors associated with appropriate treatment duration were hospitalization in intensive care unit [adjusted odds ratio (aOR), 4.46; 95% confidence interval (CI), 1.60-12.46], polymicrobial infection (aOR, 3.97; 1.32-11.92) and antibiotic control team intervention (aOR, 2.49; 1.27-4.87). The intervention period was associated with lower rate of nephrotoxicity (15% versus 4%, P = 0.01) and lower direct medical costs (e4039.4 per 100 persons treated). Conclusions: Aminoglycoside use was frequently associated with excessive treatment duration and incorrect drug level monitoring. Reinforcing practice guidelines through direct counselling improved the appropriateness of prescriptions.