A new drug developed by Melbourne scientists could offer hope to Australians at risk of developing blood clots during long haul flights.

For Australians heading abroad, long haul flights are a given and now scientists have developed a drug to potentially help people avoid the risk of blood clots.

Sitting for hours in the same position, with lower air pressure, less oxygen and often not enough hydration, puts many flyers at risk of developing deep vein thrombosis (DVT), caused by a blood clot most commonly in the legs.

These can develop into a pulmonary embolism, when a clump of material, most often a blood clot, travels from one's legs to the lungs.

Blood clots can trigger a potentially fatal heart attack or stroke and now scientists at Melbourne's Baker Heart and Diabetes Institute have developed a new drug to avoid the risks.

Results from a pre-clinical trial, done with Harvard Medical School in Boston, USA, have shown blood clots can be avoided by using small doses of a drug that can prevent clot growth.

Baker Institute researcher and author, Professor Xiaowei Wang, said scientists have designed the drug for targeted delivery.

"This unique approach would provide drugs that are attaching themselves to the just developing clot and block further build-up of the blood clot. They are only needed in small doses, thereby avoiding any bleeding side effects," she said.

"This approach promises to be safer compared to traditional drug administration that results in a generalised bleeding risk."

Fellow co-author, Professor Karlheinz Peter, said the innovative approach could provide an alternative for large numbers of patients who might be at risk of heart attack, stroke and deep vein thrombosis.

"More importantly, in addition to being an effective treatment for heart attacks, strokes and DVTs, a reduced bleeding risk will enable its use to protect at-risk patients even before such events occur."

Cardiovascular disease causes more than 480,000 hospitalisations annually, with one Australian dying every 12 minutes.