Presentation at CHEST 2013 reviewed key considerations surrounding the treatment of pulmonary embolism and other venous thromboembolic events with the newer class of oral anticoagulant agents.
Nearly half of physicians have treated pulmonary embolism using a novel oral anticoagulant, such as apixaban, dabigatran, or rivaroxaban, and while the use of the new drugs has been studied in randomized controlled trials in about 15,000 patients to date, their use is not recommended in certain cases, and providers need to have in place a system for educating patients who are switching from vitamin K antagonists, according to a presentation Monday at CHEST 2013, the annual meeting of the American College of Chest Physicians in Chicago.
Trials such as RECOVER in 2010, and EINSTEIN in 2010 and 2012 found that novel drugs are non-inferior to coumadin, and sometimes are associated with less bleeding. However, while rivaroxaban has FDA approval for use in treating pulmonary embolism, use of apixaban and dabigatran in such patients is off-label, and the 2013 REMEDY trial found that use of dabigatran was associated with more heart attacks than warfarin, according to Ltc. John H. Sherner, MD, program Director of the pulmonary and critical care fellowship at Walter Reed National Military Medical Center in Washington, DC.
“Trials have shown less major bleeding, less fatal bleeding or clinically-significant non-major bleeding with apixaban, and that they can be prescribed for extended use without monitoring, but you still have to ask which patients are right for these agents,” said Sherner.
“First you have to ask, ‘How are they doing on coumadin?’” suggested Sherner, who gave a presentation titled “Clinical Use of New Anticoagulant Agents.” Sherner noted the publication this year in the journal CHEST of a new scoring system for making such decisions. Patient have a point added to their score if female or under 60, among other considerations, and two points if they are non-Caucasian or have used tobacco in the past two years. “If they have a low score, such as zero or one, they could do well if you switch to a novel agent, but their score is greater than one, they would probably do better to stick with coumadin,” Sherner said.
In addition, use of the novel agents is contraindicated in certain patients, such as those with cancer or who are pregnant, because the new drugs have not been studied in enough patients for physicians to know whether they are effective, according to Sherner. Also, apixaban is not recommended for those treated with itraconazole for toenail fungus, according to the American Podiatric Medical Association, he added.
“These agents can be slightly pro-thrombotic, and intra-cranial bleeding is the most feared complication in these cases,” Sherner explained. When bleeding occurs, the doctor should first stop the drug, he said. “Hemodialysis is an effective option for bleeding in patients treated with dabigatran, but not other agents,” he said. “In other cases, you can use charcoal if the drug ingestion was recent, or pro-thrombin complex concentrates. There is no true antidote to these drugs, but antibody antidotes are in development,” he added.