Common Motion Sickness Drug Could Impair Divers' Judgment
Dimenhydrinate, on the other hand, was associated with much
lower scores on a test that required the subjects to switch rapidly between two
tasks and is a measure of mental flexibility. "We showed a definite
impairment [from dimenhydrinate], especially in combination with narcosis, and
the deeper you go, the greater your decline," says O'Toole, an experienced
diver who directs the hyperbaric medicine program at the University of
Pittsburgh. "I would not recommend that someone take this drug and
Add dimenhydrinate to the effects of narcosis "and you're
really zonked," says Murray Grossan, MD, a Los Angeles-based
otolaryngologist and a scuba diver since 1970. He tells WebMD that many fatal
diving accidents occur because divers ignore or forget to watch the monitors
that tell them they're low on air, which could be the result of impaired
judgment produced by narcosis. Grossan was not involved in the study.
However, the potential effects of pseudoephedrine on heart
function should not be dismissed, warns Claes Lundgren, MD, PhD, director of
the Center for Research and Education in Special Environments at the State
University of New York in Buffalo. People diving at great depths may experience
an immersion effect, in which blood travels away from the limbs and into the
chest, where it may distend the heart and render it more vulnerable to the
effects of drugs that affect heart rhythm. "This could be responsible for a
number of scuba deaths that remained unexplained," he tells WebMD.
Grossan says that his patients have found the scopolamine patch
to be a good antidote to seasickness. They can remove it just before diving or
wear it in the water if they dive with a hood. Some people also have had good
luck with wristbands that compress certain pressure points and are reported to
"It's worth noting that neither of these drugs is permitted
for commercial pilots," says Lundgren. "Risk is a relative concept.
[When it comes to diving after taking one of these drugs], it's really for the
individual to define for him- or herself what is acceptable."