Old drug can stop clots as well as newer drug does

A decades-old form of the anticlotting drug heparin is as safe, as effective, and potentially as convenient to use as recent derivatives that are many times as expensive.

Some people who develop blood clots deep in leg veins receive plain heparin, which can prevent subsequent, sometimes-deadly clots. Others get low-molecular-weight heparin, which comes in several varieties and is sold by various manufacturers.