We evaluated in-flight use of medications from astronaut debriefings after
79 U.S. Space Shuttle missions. From the 219 records obtained (each represe
nting one person-flight), 94% included some medication being taken during f
light; of that number, 47% were for space motion sickness, 45% for sleep di
sturbances, and smaller percentages for headache, backache, and sinus conge
stion. Drugs were taken most often orally, followed in decreasing order of
frequency by intranasal, intramuscular, and rectal routes. Drugs for space
motion sickness were taken mostly during the first 2 d of flight, drugs for
pain during the first 4 d, and drugs fur sleeplessness and sinus congestio
n were taken consistently for 9 flight days. About 85% of all doses had no
reported side effects, and most of the side effects that were reported happ
ened during the first mission day. About 80% of the drug-dose events were p
erceived effective by the recipients; most of the reports of ineffectivenes
s occurred during the first mission day. Promethazine, the only drug given
by three different routes (orally, intramuscularly, and rectally), was most
effective and had minimal side effects when taken intramuscularly. This in
formation, although useful, should be expanded to include objective measure
s of effectiveness so that therapeutic efficacy can be assessed during flig
ht.