When it comes to crew missions Mars there is no shortage of dangers, from space radiation to a hostile environment. Now researchers have found another problem: Many of the medicines that astronauts can take with them are likely to expire before they return to Earth.
Researchers say they discovered a host of drugs used in space have a shelf life of three years or less — a problem given Nasa expects a mission to Mars to take about 36 months.
Dr. Dan Buckland, the senior study author from the Duke University School of Medicine, said that medications that expired on Earth were usually less effective, although how much is unpredictable.
“The risk is that an illness will end up being more severe later in a Mars mission than it was earlier in the mission before the medication expired,” he said.
Buckland and colleagues used a Freedom of Information Act (FoI) request to obtain a list of the medications on board the International Space Station (ISS). Although the exact medications that will be taken to Mars are not yet known, Buckland said that those on the ISS would likely make up the bulk of a medical kit for such a mission.
The team wrote in the journal npj Microgravity how they found terrestrial shelf life data for 91 of the 106 medicines on the 2023 ISS list, with their maximum shelf life dates suggesting that 54 of the medications would expire by 36 months, including certain pain relievers.
Fourteen of the medications will expire by 24 months, including one advanced life support medication, one anaphylactic treatment medication, two antibiotics and one antipsychotic.
When each medication’s minimum shelf life was taken into account, 89 of the 106 medications were found to expire by 36 months.
The authors said the expiration dates refer to the drug in its original packaging, meaning it could be shorter if it is repackaged, as it often is on the ISS.
Previous studies have shown that astronauts on the ISS report the daily use of medication on board, indicating its importance.
But while the ISS can be regularly resupplied, such capabilities — as well as emergency evacuation — may not be possible for astronauts on long missions, making medication expiration a concern.
“Hopefully, this work can guide the selection of appropriate medications that last for the duration of a mission or increase the amount of medications responsible for reduced effectiveness,” Buckland said.
“Alternatively, it may provide the knowledge needed for informed consent discussions with exploration teams that allow them or responsible parties to accept the risk of less effective medications.”
