Storage temperatures of out-of-hospital medications

Abstract

Objectives: To determine whether temperatures inside drug boxes used in the out-of-hospital setting are within the U.S. Pharmacopeia recommendations for 'controlled room temperature,' which is defined as a temperature maintained between 15°C and 30°C with a mean kinetic temperature less than 25°C, and to determine whether time-temperature indicator labels can reliably monitor mean kinetic temperatures. Methods: Two methods were used to monitor temperatures: miniature electronic temperature recorders and color- changing time-temperature indicator labels. These were placed in drug storage boxes of advanced life support units over three summer months and two winter months. Results: In summer, the electronic recorders logged temperatures exceeding 30°C in all drug storage boxes, ranging from 3% to 29% of the total time. The mean kinetic temperatures by location for the whole period ranged from 21°C to 30°C. In the winter, the electronic recorders logged temperatures exceeding 30°C at one location 2% of the total time. There were significant temperature excursions below 15°C at all locations, ranging from 16% to 90% of the total time. At one location, there were temperature readings below 0°C for 9% of the total time. The mean kinetic temperatures obtained from the electronic recorders and the indicator labels differed by less than 1°C. Conclusions: This study demonstrates that out-of-hospital medications are subject to temperatures both above and below recommended storage temperatures. Time-temperature indicator labels can reliably monitor exposure to elevated temperatures.