IV to Oral Diltiazem Conversion Guidelines

Introduction to Conversion

The American College of Cardiology recommends administering oral diltiazem CD 180-360 mg once daily, typically 300 mg, and discontinuing the IV infusion 4 hours after the first oral dose when converting from IV to oral diltiazem 1

The American College of Cardiology suggests monitoring blood pressure for hypotension, which is the most common adverse effect 2
The American Heart Association recommends monitoring signs of bradycardia or heart block during the transition period 1, 2
Monitoring symptoms of worsening heart failure in at-risk patients is crucial during the transition period, as recommended by the American College of Cardiology 2, 3
The American College of Cardiology advises against converting to oral diltiazem in patients with second or third-degree AV block without a functioning pacemaker 2, 3
Contraindications for conversion include decompensated systolic heart failure or severe LV dysfunction, as stated by the American Heart Association 1, 2, 3
The American College of Cardiology recommends avoiding conversion in patients with cardiogenic shock, WPW syndrome with atrial fibrillation/flutter, or symptomatic hypotension 2, 3

The American College of Cardiology suggests adjusting dosing in hepatic or renal dysfunction, as diltiazem is metabolized by the liver and may require dose adjustment in renal impairment 2, 3
For patients on a higher IV infusion rate (>10 mg/hour), the American Heart Association recommends considering starting with diltiazem CD 360 mg/day 1

The American College of Cardiology advises using caution with certain medications, such as apixaban, itraconazole, bosutinib, ceritinib, cilostazol, cyclosporine, everolimus, ibrutinib, idelalisib, ivabradine, lomitapide, olaparib, ranolazine, rifampin, and simeprevir, due to potential interactions with diltiazem 2, 3