Evaluation of Drug Stability Under Real-World Environmental Stress in Emergency Medical Service Setting in Qatar: A...

Medications in emergency medical services vehicles in International Council for Harmonization zone IV regions (e.g., Qatar) are subject to environmental stress, potentially compromising stability. Real-world long-term data remains limited.

This study aims to investigate the stability of 13 essential medications stored in operational Hamad Medical Corporation Ambulance Service (HMCAS) vehicles over 1 year under uncontrolled storage conditions, regardless of expiry dates and organizational drug replacement practice.

From January to December 2021, over 1600 samples of 13 critical care medications (126 samples of each medication) were placed in six rapid response cars (RRCs) across seven intervals over a year. Medications were exposed to real-world conditions of heat, humidity, vibration, and light; controls were stored under manufacturer-recommended laboratory conditions. Drug concentration was analyzed using high-performance liquid chromatography with ultraviolet detection.

Ten medications, including rocuronium, nitroglycerine, and ondansetron, remained within United States Pharmacopeia/British Pharmacopoeia limits, validating current HMCAS storage protocols. Rocuronium, typically replaced every 60 days, remained stable across all intervals. Epinephrine exhibited the highest instability (24/126 samples <90% labeled content), followed by furosemide (21/126 < 90%). Insulin demonstrated greater variability (7/126 > 105% and 1/126 < 95%). Most outliers clustered in three specific RRCs, suggesting vehicle-specific variation in environmental exposure.

These findings highlight the fact that despite the very harsh environmental conditions to which the medications have been exposed to, deviating from our normal medication management practices, most medications remained stable. Only epinephrine, furosemide, and insulin exhibited some content variability. In real practice, this would not have occurred due to HMCAS drug monitoring and replacement cycles.