Ambulance Drugs May Degrade, Become Unstable Quickly: Study

New research raises potential questions about the safety of drugs kept in ambulances and used in emergency situations, suggesting that the medications may degrade much more quickly than expected, some within only a few weeks.  

In a study published in the Annals of Emergency, researchers tested certain drugs stored under three different conditions over the course of one year. Researchers at the University Hospitals Leuven in Belgium kept drugs at room temperature, inside a cooled refrigerator and in an emergency response vehicle.

The drugs tested included the allergy and heart drug epinephrine, common muscle relaxers Nimbex and succinylcholine chloride, seizure medication Activan, and Methergine, which helps stop bleeding after a woman has given birth. They took samples of the drugs weekly during the first month and then monthly for one year.

Sabrina De Winter and her team of researchers discovered Activan became unstable within only four weeks at room temperature or four weeks inside of an ambulance. Nimbex became unstable at the four month marker at room temperature, but remained stable for four months in an ambulance.

The succinylcholine remained stable for two months at room temperature and only one month in an ambulance. The study also found epinephrine and Methergine remained stable for one year at room temperature and in ambulances.

Drugs were considered stable if their potency remained above 90 percent, which is a benchmark commonly used to determine if medications are usable or not. The use of less potent drugs may cause them to become ineffective, causing weaker results or potentially lead to severe side effects.

The authors say that this study highlights a need for more research like it, considering very few studies have analyzed the efficacy of drugs in an ambulance setting or the effectiveness of the drugs within or past the expiration dates. Drugs stored in ambulances are often exposed to extreme temperature variations, motion and sunlight.

“Real-world EMS working conditions pose challenges for maintaining optimal efficacy of these important EMS drugs,” said study authors.

According to the researchers, many emergency technicians err on the side of caution and throw out drugs prior to their expiration date. Studies focusing on drug effectiveness and expiration dates may help prevent wasted money, side effects from emergency technicians using ineffective drugs or a decreased supply of medication.

The researchers recommend removing the drugs from emergency technician backpacks at the end of the recommended timeframes to maintain potency and avoid problems that may be caused from ineffectiveness.