A study published in Annals of Internal Medicine found that atrial fibrillation patients taking diltiazem with the blood thinners apixaban or rivaroxaban have a higher risk of serious bleeding than those using metoprolol. “These findings are particularly important at the population level,” said Ghadeer Dawwas, PhD, MBA, noting that in high-risk patients—especially at higher diltiazem doses—clinicians should carefully consider drug interactions, with metoprolol potentially representing a safer alternative.