New drug may prevent more hip-surgery blood clots

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New drug may prevent more hip-surgery blood clots

Last Updated: 2002-05-17 9:58:37 -0400 (Reuters Health)

Amy Norton

NEW YORK (Reuters Health) - Two international studies suggest a newer

type of drug may work better than standard ones in preventing blood

clots after hip-replacement surgery.

Both studies compared the newer anti-clotting drug fondaparinux with a

standard drug called enoxaparin, and found that fondaparinux patients

were less likely to develop blood clots in the legs known as deep vein

thrombosis (DVT).

In earlier work, the same team of researchers had found the drug bested

enoxaparin in patients undergoing major knee surgery or surgery for hip

fractures. The two new studies looked at patients getting elective hip

replacement.

The results of the four studies " are all consistent with each other, "

one of the authors, Dr. G. G. Turpie of Hamilton Health

Sciences Corporation in Canada, told Reuters Health.

The risk of DVT is fairly high after major orthopedic procedures like

total hip or knee replacement, but anti-clotting drugs cut this risk

significantly. Even with treatment, however, some patients still develop

DVT. These leg clots often present no problem, but occasionally the

clots travel to the lungs where they can lead to a potentially fatal

condition called pulmonary embolism.

In one of the new studies, led by Dr. Rud Lassen of the

University Hospital of Copenhagen in Denmark, 4% of fondaparinux

patients developed DVT or pulmonary embolism within 11 days of hip

replacement. That compared with 9% of those who took enoxaparin.

The death rate up to 7 weeks after surgery did not differ between the

two groups and was low--only six of nearly 2,300 patients overall died.

In the second study, fondaparinux patients again had a lower rate of DVT

and pulmonary embolism--although, statistically, the difference was not

significant, according to researchers.

Both reports are published in the May 18th issue of The Lancet. The

studies were funded by Sanofi-Synthelabo and NV Organon, the

co-developers of fondaparinux. The drug, marketed as Arixtra, was

approved for use in the US late last year.

Fondaparinux may indeed " herald a new era " in the prevention of DVT and

pulmonary embolism, according to an accompanying editorial.

However, it is not for all patients since the drug could carry a higher

risk of bleeding than other anti-clotting agents, write Drs. Henri

Bounameaux and Perneger of University Hospitals of Geneva in

Switzerland.

Overall, in the four trials of the drug, serious bleeding was about 1%

more frequent with fondaparinux than with enoxaparin, they note.

Some " fragile " patients--such as those who are underweight or have

kidney impairment--should not receive the drug, the editorialists write.

SOURCE: The Lancet 2002;359:1715-1720.