While numerous clinical trials have proven that these drugs can save lives, correct dosing is crucial, the researchers said, since the therapeutic window is narrow. Too much of the drug can lead to bleeding episodes, while too little may be ineffective at stopping the clotting process.
The Duke researchers believe that when evaluating these patients in emergency rooms, physicians should spend a little more time clarifying information such as weight and kidney function which are necessary for accurate dosing. The researchers also hope that the results of their analysis provide concrete steps to improve safety thereby increasing physician confidence in using these drugs on high risk patients, who have the most to gain.
"These drugs are clearly beneficial, and when dosed correctly, are also safe," said Duke cardiologist Karen Alexander, M.D., lead investigator of the study published Dec. 28, 2005, in the Journal of the American Medical Association.
The drugs in question unfractionated heparin (UFH), low-molecular-weight heparin (LMWH) and glycoprotein IIb/IIIa inhibitors work by either preventing the aggregation of platelets in coronary arteries or interfering with the formation of blood clots. The drugs are typically given within the first 24 hours of heart attack symptoms, and it is not uncommon for patients to receive combinations of these drugs during their hospital stay. Doses are determined by patient-specific data incorporated into standard prescribing algorithms.
"Our analysis, which includes patients treated in all types of hospitals across the country shows that dosing errors occur more often in vulnerabl
Contact: Richard Merritt
Duke University Medical Center