Most medications need to be stored in a cool dry place. Injectable drugs, in particular, often need to be refrigerated to maintain potency. And no place is this more crucial than in emergency response vehicles!
A new study from Belgium suggests that injectable drugs stored in ambulances may lose potency much more quickly than most health professionals realize. Researchers compared the activity of an antiseizure drug called lorazepam stored at room temperature, in the refrigerator or in the back of an ambulance. The refrigerated drug lasted well for a year, but the lorazepam in the ambulance had lost substantial potency within one month.
A muscle relaxant called succinylcholine also began to deteriorate after a month, even though the expiration date was much longer. The implication of this research is that temperature variations and light exposure may shorten the useful lifespan for certain medications. This may also raise a red flag for liquid medications shipped to patients by mail order. If they sit for hours in a hot mailbox, such formulations may lose potency faster than expected.
[Annals of Emergency Medicine, online May 28, 2013]
