From the Guidelines
Isosorbide mononitrate should be used with caution and under the guidance of a healthcare provider, as it can cause nitrate tolerance and its effectiveness may be limited by the development of tolerance, as noted in the European Heart Journal study 1.
Key Considerations
- The medication is primarily used to prevent angina (chest pain) in patients with coronary artery disease.
- The typical starting dose is 30-60 mg once daily, which can be increased to 120 mg daily if needed, as part of a comprehensive treatment plan that includes a nitrate-free period to prevent tolerance.
- It works by relaxing and widening blood vessels, improving blood flow to the heart muscle and reducing the workload on the heart, as described in the study published in the European Heart Journal 1.
Important Safety Information
- Patients should not take phosphodiesterase-5 inhibitors (like sildenafil, tadalafil) while using isosorbide mononitrate, as this combination can cause dangerous drops in blood pressure, highlighting the need for careful management and monitoring.
- Common side effects include headache, dizziness, and lightheadedness, especially when starting treatment, which often diminish over time, as reported in the study 1.
- The medication should be taken consistently, not just when experiencing chest pain, as it works preventatively rather than for acute relief, and patients should be aware of the potential for nitrate tolerance and its impact on treatment effectiveness.
Clinical Guidelines and Recommendations
- The American College of Cardiology Foundation/American Heart Association task force on practice guidelines recommends the use of isosorbide dinitrate in combination with hydralazine for certain patients with heart failure, as outlined in the 2013 ACCF/AHA guideline for the management of heart failure 1.
- However, the use of isosorbide mononitrate should be individualized and guided by the patient's specific clinical needs and medical history, taking into account the potential benefits and risks of treatment, as well as the need for ongoing monitoring and management to minimize the risk of adverse effects.
From the FDA Drug Label
INDICATIONS AND USAGE Isosorbide mononitrate extended-release tablets are indicated for the prevention of angina pectoris due to coronary artery disease. WARNINGS Amplification of the vasodilatory effects of isosorbide mononitrate by sildenafil can result in severe hypotension. The primary use of isosorbide mononitrate is for the prevention of angina pectoris due to coronary artery disease 2. Key points to consider when using isosorbide mononitrate include:
- Contraindications: not recommended in settings of acute myocardial infarction or congestive heart failure due to the risk of hypotension and tachycardia 2
- Interactions: may result in severe hypotension when combined with sildenafil 2
From the Research
Isosorbide Mononitrate Efficacy
- Isosorbide 5-mononitrate appears to be at least as effective as isosorbide dinitrate in the prophylaxis of angina pectoris 3
- A controlled-release formulation of isosorbide 5-mononitrate given once daily has a significantly better antianginal effect than placebo without inducing tolerance 3
Comparison with Other Antianginal Medications
- Isosorbide 5-mononitrate is probably superior to calcium antagonists in the treatment of angina pectoris 3
- Ranolazine, a newer antianginal medication, has been shown to be effective in patients with chronic stable angina, including those with diabetes mellitus 4, 5, 6
- Ivabradine, another antianginal medication, has also been shown to be effective in patients with microvascular angina pectoris 5, 6
Safety and Tolerability
- The safety and tolerability profiles of ranolazine and ivabradine have been compared, with ranolazine showing a better profile than ivabradine in one study 7
- Common adverse reactions reported with ivabradine include dizziness, headache, and backache, while ranolazine has been associated with nausea, dizziness, and vomiting 7