What is the treatment for unstable angina using Isordil (isosorbide dinitrate)?

From the Guidelines

Isordil (isosorbide dinitrate) should be used in conjunction with other therapies, such as β-blockers, for the management of unstable angina, as it provides symptom control through vasodilation. According to the American Heart Association council for high blood pressure research 1, the initial therapy for unstable angina or NSTEMI should include short-acting β-selective blockers without intrinsic sympathomimetic activity, usually intravenously, in addition to nitrates for symptom control.

Key Points to Consider

• Isordil can be administered sublingually at 2.5-5 mg every 5-10 minutes for up to three doses to provide rapid relief for acute unstable angina episodes.
• For long-term management, oral Isordil is typically prescribed at 5-40 mg three to four times daily.
• It is essential to space doses throughout the day and take the last dose no later than 7 PM to prevent nitrate tolerance.
• Common side effects of Isordil include headache, dizziness, and hypotension, and patients should be advised to sit or lie down when taking the medication to prevent falls due to potential blood pressure drops.
• Isordil should never be taken with erectile dysfunction medications like sildenafil (Viagra) as this combination can cause dangerous drops in blood pressure.

Mechanism of Action

Isordil works by dilating blood vessels, which reduces the heart's workload and improves oxygen supply to the heart muscle, helping to relieve chest pain and prevent further angina attacks, as recommended by the American Heart Association council for high blood pressure research 1.

From the FDA Drug Label

Isosorbide dinitrate sublingual tablets are indicated for the prevention and treatment of angina pectoris due to coronary artery disease. Isosorbide dinitrate tablets are indicated for the prevention of angina pectoris due to coronary artery disease.

The provided drug labels do not specifically mention unstable angina.

• The labels mention angina pectoris due to coronary artery disease.
• Unstable angina is not directly addressed in the labels.
• Therefore, no conclusion can be drawn about the use of Isordil (isosorbide dinitrate) for unstable angina 2, 2, 3.

From the Research

Unstable Angina and Isordil Treatment

• Unstable angina is an intermediate stage in acute coronary ischemic syndromes, accounting for about 50% of all admissions to coronary care units in the United States 4.
• The primary goals in treatment of unstable angina are to relieve pain and prevent or limit myocardial infarction or ischemia 5.
• Management of unstable angina includes:
  • Acute management: bedrest, aspirin, heparin, nitroglycerin (glyceryl trinitrate) infusion, and beta-blockers and calcium channel blockers in selected cases 4.
  • Long-term management: aspirin and beta-blockers, if there is prior infarction, and control of conventional risk factors 4.
• Isordil, a brand name for isosorbide dinitrate, is a type of nitrate used to treat angina pectoris, but its specific use in unstable angina is not directly mentioned in the provided studies.
• However, nitrates, such as nitroglycerin, are commonly used in the treatment of unstable angina to alleviate angina pain and improve exercise tolerance 6, 7.

Treatment Strategies

• Aspirin and heparin are used to reduce the risk of myocardial infarction in unstable angina patients 6, 7.
• Beta-blockers and calcium channel blockers may be used in selected cases to relieve pain and improve symptoms 4, 5.
• Coronary angiography and angioplasty or bypass surgery may be performed in patients who are refractory to optimal medical therapy or have high-risk features 4, 5, 8.
• The choice of treatment strategy depends on the individual patient's risk factors, clinical presentation, and response to initial therapy 8.