Effects of clinical decision support on initial dosing and monitoring of tobramycin and amikacin

Purpose. The impact of clinical decision support (CDS) on initial doses and intervals and pharmacokinetic outcomes of amikacin and tobramycin therapy was evaluated. Methods. A complex CDS advisor to provide guidance on initial dosing and monitoring of aminoglycoside orders, using both traditional-dosing and extended-interval-dosing strategies, was integrated into a computerized prescriber-order-entry (CPOE) system and compared with a control group whose aminoglycoside orders were closely monitored by pharmacists. The primary outcome measured was an initial dose within 10% of a dose calculated to be adherent to published dose guidelines. Secondary outcomes included a guideline-adherent interval, trough and peak concentrations in goal range, and rate of nephrotoxicity. Results. Of 216 patients studied, 97 were prescribed amikacin and 119 were prescribed tobramycin. The number of orders with initial doses consistent with reference standards increased from 40% in the preadvisor group to 80% in the postadvisor group (p < 0.001). Selection of the correct initial interval based on renal function increased from 63% to 87% (p < 0.001). The changes in the initial dosing and interval resulted in an increase of trough concentrations at goal (59% in the preadvisor group versus 89% in the postadvisor group, p = 0.0004). There was no significant difference in peak concentrations in the goal range or rate of nephrotoxicity. Conclusion. An advisor for aminoglycoside dosing and monitoring integrated into a CPOE system significantly improved selection of initial doses and intervals and resulted in an improvement in the rate of trough serum drug concentrations at goal compared with standard provider dosing.