Suboptimal storage conditions
Studies suggest that freeze-dried plasma stored in army field conditions is safe to use two years after the expiry date, with only a slight reduction of efficacy (7).
Tranexamic acid, which is used for prehospital bleeding control, has been tested after being kept in field conditions at temperatures between –20 and 50 °C for 12 weeks, without any demonstrable loss of potency in vitro (8).
American researchers who found and tested various tablets from a closed-down pharmacy, showed that 86 % of medications that had expired 28–40 years ago, had at least 90 % of their active substances intact (8). When medications had degraded, the cause was likely to be ingress of moisture through the packaging, leading to hydrolysis. However, acetylsalicylic acid had probably degraded spontaneously (3).
In the atmosphere, there is weightlessness and higher background radiation. In 2015, the international space station sent medications by satellite to Earth in order to study medication degradation (9). The medications' use-by date had already expired, but eight out of nine were nevertheless approved since more than 90 % of their active substances remained. Melatonin was not approved.
There is much to suggest that many medications that have been stored in suboptimal conditions continue to have the desired effect
In 2022, nine drugs intended for use by emergency medical services were deposited with two rescue helicopters in Switzerland and exposed to temperature fluctuations between –1.2 and 38.1°C for one year. According to the manufacturers, the drugs had to be kept at room temperature, but the researchers found no demonstrable degradation or loss of potency after the experiment. The drugs that were tested included adrenalin 1 mg/ml, noradrenaline 1 mg/ml, amiodarone 150 mg/3 ml, midazolam 15 mg/3 ml, fentanyl 100 ug /2 ml, naloxone 0.4 mg/1 ml, etomidate 20 mg/10 ml, ketamine 100 mg/2 ml and rocuronium 100 mg/10 ml. Amiodarone showed a tendency towards transient micro-crystallisation at low temperatures (10).
There is much to suggest that many medications that have been stored in suboptimal conditions continue to have the desired effect. They should therefore be considered for use in situations where resources are scarce. It should also be widely investigated what expired medications can be administered to patients and injured people in a crisis if other medications are not available.
A system that allows some medications to be put into storage rather than being destroyed after the expiry date can help with providing simple and inexpensive medication preparedness at a local level. Now is the time to put this issue on the agenda.