Scientists in Argentina believe they have discovered another use for Viagra.
Viagra (sildenafil) which was originally developed to treat high blood pressure and angina has become far more famous and lucrative for it's use in treating erectile dysfunction.
Now researchers have apparently discovered that it may also be useful in combating jet lag.
Jet lag occurs when a person's circadian cycle is disturbed by moving across many different times zones and causes problems with concentration, sleepiness and insomnia, which can be dangerous to people such as airline pilots or shift workers.
It seems the anti-impotence drug helped hamsters recover more quickly when their sleep patterns were disturbed by bright lights.
The researchers from the National University of Quilmes in Buenos Aires, injected hamsters with sildenafil at night then disturbed their sleep pattern by rousing them six hours prematurely early with bright lights.
The adult male hamsters were given either a placebo or Viagra and it was found that the creatures dosed with Viagra recovered from the simulated jet-lag 50% quicker than the ones that only received a placebo.
The researchers found that these creatures appeared unaffected by the disturbance of their sleep and on waking began running in their exercise wheels.
However, the drug only worked when applied before an advance in the light-dark cycle, equivalent to an east-bound flight.
They response was not the same when westbound travel was simulated by delaying the turning on of lights.
Viagra affects an enzyme that reduces levels of a naturally occurring compound in the brain, cyclic guanine monophosphate (cGMP), which helps regulates the circadian cycle, the body's internal clock.
Lead investigator Diego Golombek says there is no reason to believe it should not work in humans.
Golombek says however that clinical trials should be undertaken using smaller doses of Viagra for helping people to cope with jet-lag before Viagra can be confirmed as a useful and safe treatment in such situations.
Viagra is produced by drug giant Pfizer and was approved by the U.S. Food and Drug Administration in 1998 for the treatment of erectile dysfunction.
The research is published in the Proceedings of the National Academy of Sciences.