Space motion sickness symptoms are similar to motion sickness on Earth. About 70 percent of first-time space travelers develop the condition during the first few hours in space with symptoms peaking around 10 hours into the flight. The condition can recur when returning to Earth's gravity, which, along with takeoff, is one of many critical events during space flight.
The medications currently available affect a person's cognitive ability.
"Astronauts typically take promethazine, a medication used to treat nausea. It's a good medicine, but it causes sedation," said Dr. John L. Dornhoffer, a researcher on the National Space Biomedical Research Institute's (NSBRI) neurovestibular adaptation team. "Astronauts have worked all their lives to do this job, and they want to avoid taking something that makes them sleepy."
The drugs can impair the ability to react quickly, think clearly and recall information, so spacewalks are out of the question. And, extravehicular activity is never an option when a crewmember feels nauseous.
An ear, nose and throat specialist, Dornhoffer is researching four drugs lorazepam, meclizine, promethazine and scopolamine to determine what drug is most effective at reducing space motion sickness without impacting cognitive and physical ability. His team is also researching the most effective way to administer the medications.
"These drugs are used to treat balance disorders, and all have central nervous system side effects. We are using cognitive tests to determine which medication causes the least impairment," said Dornhoffer, associate professor of otolaryngology at the University of Arkansas for Medical Sciences and executive director of the Prosper Meniere Soci
Contact: Kathy Major
National Space Biomedical Research Institute