To: Stephen How who wrote (842 ) 4/22/1998 8:41:00 AM From: Jim Roof Read Replies (2) | Respond to of 1432
<<The Hespan package insert gives some insight into the effects of hetastarch on coagulation. Note the maximum recommended dosage in the insert (20mL/kg/day), and the direct effect of hetastarch on reducing Factor VIII and platelets, and increasing PT and PTT. I reviewed the Hextend Phase III trial results, and saw the same tell-tale effects of hetastarch on coagulation: for both treatment groups, PT and PTT were up (postop vs. preop) and hemocrit and platelet count were down.>> Steve, I too have reviewed the Hextend Phase III data and there is a clear delineation between the Hextend and Hespan (generics) group particularly in the platelet and 'crit' counts. However, I remind you again that the lowering of platelets by Hespan use is associated with a need to transfuse whole blood and the use of Hextend (which by dilution also lowers the platelet count) does not lead to as frequent bleeding, hence the post-op lower platelet count in the Phase III's. Ie., a lower platelet count is only an issue where bleeding occurs. That is the job of platelets. If Hextend can effectively help the diluted blood to clot with a lower platelet count then the lower number becomes a non-issue. By contrast, hespan and generics also lower the platelet count but then the patients start to bleed so whole blood is ordered by the physician, immediately boosting the platelets to higher numbers but of equal functionality of the Hextend patient who has received less whole blood. Your argument or implied weakness here fails to reach the critical point of consequence. Anyone can see that administering a fluid which contains no whole blood or blood products will reduce the concentration of all whole blood components by a direct effect of dilution - that's obvious. The question is "how well do the patients do with these lowered numbers?". Phase III trials indicate that Hextend is better tolerated than generic hetastarch. To beat a dead horse once again - Hextend patients' blood clotted better with the lower platelet counts than the Hespan patients did. That is why the Phase III data showed a HIGHER platelet count in the Hespan group and this was simply due to the higher amounts of blood products needed by the Hespan group to achieve adequate coagulation. Jim