Purpose Crewmembers aboard the International Space
Station (ISS) have free access to an increasing number of
medications within medical kits. The aim of the current study
was to assess the number, severity and reliability of potential
drug-drug interactions (DDIs) involving those medications.
Methods We evaluated the information obtained from clinical decision support systems. Searches for potential DDIs were
applied to published lists of medications available to US astronauts in medical kits aboard the ISS.
Results A total of 311 potential DDIs were identified by LexiInteract, of which approximately half were recognized by
Micromedex as well. Major, moderate and minor interactions
consisted 23.5%, 68.5% and 8.0% of entries, respectively.
The reliability of 71.1% of alerts was fair. Commonly used
drugs, including zolpidem and zaleplon, were involved in multiple potential interactions that were classified as major based
on additive CNS depression.
Conclusions Most potential DDIs likely to be encountered in
space are unestablished even in terrestrial medicine and their
assignment is based on class-effects. Yet, some drug combinations may be associated with clinically-relevant consequences.
Future DDI rating should be adjusted to space-related outcomes. Until that happens, it would be advisable to avoid nonestablished drug combinations in space when possible.