Isosorbide Dinitrate Therapy for Angina Pectoris

Primary Indications

• The American College of Cardiology recommends starting with 5-80 mg of isosorbide dinitrate orally 2-3 times daily, with a typical starting dose of 20 mg three times daily, for the prevention of angina pectoris in patients with coronary artery disease who require long-acting nitrate therapy 1, 2, 3
• The slow-release formulation can be dosed at 40 mg once or twice daily for angina prevention 1, 2
• Maximum doses reach 120 mg daily in divided doses for patients with angina pectoris 4

Specific Clinical Scenarios

• The American Heart Association recommends prescribing the combination of hydralazine and isosorbide dinitrate (20-40 mg three times daily) for self-identified Black or African American patients with NYHA class III-IV heart failure and LVEF ≤40% who are already on ACE inhibitors/ARBs and beta-blockers 4, 5
• This combination reduces both morbidity and mortality in this population, with a target dose of 40 mg isosorbide dinitrate three times daily 5, 3

Dosing Strategy to Prevent Tolerance

• The American College of Cardiology recommends implementing a nitrate-free interval of 10-14 hours daily to maintain efficacy 1, 2, 6
• A twice-daily regimen with doses 12 hours apart (e.g., 8 AM and 8 PM) provides a built-in nitrate-free interval 1
• A three-times-daily regimen with doses at 0800, 1400, and 1800 hours creates a 14-hour overnight nitrate-free period 1, 2

Contraindications and Precautions

• The American College of Cardiology advises against concurrent or recent phosphodiesterase-5 inhibitor use (sildenafil within 24 hours, tadalafil within 48 hours) due to risk of life-threatening hypotension 1, 7, 2
• Systolic blood pressure <90 mm Hg or ≥30 mm Hg below baseline is an absolute contraindication for isosorbide dinitrate therapy 1, 2

Combination Therapy

• The American College of Cardiology recommends always prescribing isosorbide dinitrate with a beta-blocker when possible to counteract reflex tachycardia and contractility increases that offset the reduction in myocardial oxygen demand 1, 2
• In HFrEF patients, ensure ACE inhibitor/ARB/ARNI and beta-blocker therapy is optimized before adding hydralazine/isosorbide dinitrate 5