MedWire (is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited.In neonates and children, the Low Molecular Weight Heparin of choice is 'Enoxaparin' (Clexane) as this is the only LMWH available in Australia that has had paediatric dose-finding studies.

Large-scale production processes are required before clinical trials can be carried out. However, they note that at present, the antithrombin variant can only be produced on a small scale. 'These results clearly demonstrate that AT-N135Q-Pro394 can reverse the anticoagulant activity of fondaparinux and thus could be used as an antidote for this drug ,' write the researchers in the journal Blood. The researchers observed a similar antidote effect in vivo, as administration of AT-N135Q-Pro394 to mice treated with fondaparinux at five times the curative dose neutralized 86% of the anti-Xa activity within 5 minutes. In additon, AT-N135Q-Pro394 decreased UFH and LMWH anticoagulant activity by 76% in overdosed plasma, indicating that it acts as a potent antidote to all heparin-like anticoagulants.

Moreover, the antidote effect was dose-dependant. They found that AT-N135Q-Pro394, at a concentration equal to the endogenous plasma antithrombin concentration, significantly reduced the fondaparinux concentration from 3.0 to 1.23 mg/l - a concentration equivalent to that used for curative treatment.

To test the antidote's ability to reverse fondaparinux overdose, they added increasing concentrations of AT-N135Q-Pro394 to plasma spiked with approximately three times the maximal curative dose of fondaparinux.

What is the antidote for heparin