WASHINGTON - The male impotence drug Viagra may be useful for treating jet
lag as well, according to Argentine researchers who gave it to hamsters made to
feel like rodent globe-trotters.
The researchers manipulated the
schedule of turning lights on and off to induce jet lag in the laboratory
animals, they reported on Monday in the Proceedings of the National Academy of
Viagra pills in an undated file photo. The male impotence
drug Viagra may be useful for treating jet lag as well, according to
Argentine researchers who gave it to hamsters made to feel like rodent
Adult male hamsters given Viagra, also called sildenafil, recovered from jet
lag up to 50 percent faster than hamsters that were not given it, the
The scientists stopped giving the hamsters the highest dose they had been
using in the experiment due to a certain side effect.
"However, we used the intermediate dose for the rest of the experiments
because at that dose animals did not manifest the effects of sildenafil-induced
penile erections," they wrote.
Flying across multiple time zones can confuse one's sleep-wake cycle,
resulting in the condition called jet lag, marked by insomnia, sleepiness and
Researchers Patricia Agostino, Santiago Plano and Diego Golombek of the
Universidad Nacional de Quilmes in Buenos Aires gave doses of Viagra to the
hamsters at night, then switched on bright lights six hours early to simulate
They judged how well the hamsters adjusted to the changes by observing when
they began running on exercise wheels.
The drug helped the rodents cope with jet lag only when given before the
equivalent of an eastbound flight, not the reverse when they delayed turning on
lights to simulate westbound travel, the study found.
The researchers said the findings suggested that Viagra could be useful to
help people cope with jet lag or shift work. They said the dose needed for such
uses could be lower than the one used for treatment of erectile dysfunction.
Viagra interferes with an enzyme that lowers levels of a naturally occurring
compound that plays a role in the regulation of the circadian cycle, the body's
internal clock, the researchers said.
Viagra is marketed by Pfizer, the world's largest drug
maker. The US Food and Drug Administration approved it to treat erectile
dysfunction in 1998.