What is the recommended dosage and management of Imdur (isosorbide mononitrate) for angina pectoris?

From the Guidelines

Imdur (isosorbide mononitrate) should be initiated at a dose of 20 mg twice daily for angina pectoris, with a maximum recommended dose of 240 mg daily, as indicated in the most recent guidelines 1. The medication should be taken in the morning on an empty stomach to maximize effectiveness. For extended-release formulations, tablets should be swallowed whole, not crushed or chewed. A nitrate-free interval of 10-14 hours daily is essential to prevent tolerance development, which is why once-daily dosing in the morning is preferred. Some key points to consider when managing angina pectoris with Imdur include:

• Dose adjustments should be made gradually based on patient response and tolerance, with increases typically made at 2-3 day intervals.
• Common side effects include headache, dizziness, and hypotension, which often diminish with continued use.
• Patients should avoid concurrent use of phosphodiesterase-5 inhibitors (like sildenafil) due to risk of severe hypotension.
• Imdur works by releasing nitric oxide, causing vasodilation of coronary and peripheral vessels, which reduces cardiac workload and oxygen demand while improving myocardial oxygen supply.
• This medication is most effective as part of a comprehensive angina management plan that includes lifestyle modifications and other anti-anginal medications as needed, as outlined in the guidelines 1. Key considerations for the use of Imdur in clinical practice include:
• The importance of individualizing the dose to achieve optimal symptom relief while minimizing side effects.
• The need for regular monitoring of patient response and adjustment of the treatment plan as needed.
• The potential for interactions with other medications, such as phosphodiesterase-5 inhibitors, and the need for caution when co-prescribing these agents.

From the FDA Drug Label

DOSAGE AND ADMINISTRATION: The recommended regimen of Isosorbide Mononitrate Tablets is 20 mg twice daily, with the doses seven hours apart. A starting dose of 5 mg (½ tablet of the 10 mg dosing strength) might be appropriate for persons of particularly small stature but should be increased to at least 10 mg by the second or third day of therapy Dosage adjustments are not necessary for elderly patients or patients with altered hepatic or renal function.

The recommended dosage of Imdur (isosorbide mononitrate) for angina pectoris is 20 mg twice daily, with the doses seven hours apart.

• A starting dose of 5 mg might be appropriate for persons of particularly small stature, but should be increased to at least 10 mg by the second or third day of therapy.
• Dosage adjustments are not necessary for elderly patients or patients with altered hepatic or renal function 2.

From the Research

Recommended Dosage of Imdur

• The recommended dosage of Imdur (isosorbide mononitrate) for angina pectoris is 60 mg once daily, as stated in studies 3, 4.
• This dosage has been shown to have significant antianginal and anti-ischaemic effects compared to placebo after 2 weeks of treatment 3.
• Other dosages, such as 30 mg, 120 mg, and 240 mg once daily, have also been studied, with 120 mg and 240 mg being more effective than placebo after 6 weeks 3, 5.

Management of Imdur

• Imdur should be taken once daily in the morning to provide effective prophylaxis of symptoms throughout the day 3, 4.
• The medication should not be discontinued abruptly, as this may exacerbate anginal symptoms 3.
• Patient compliance is better with once-daily administration of Imdur than with twice-daily administration of conventional isosorbide 5-mononitrate 3.
• Imdur can be used in combination with beta-blocker treatment, which has been shown to provide superior anti-anginal protection compared to beta-blocker treatment alone 4.

Efficacy and Safety of Imdur

• Imdur has been shown to be effective in reducing the frequency of angina attacks and improving exercise tolerance in patients with stable angina pectoris 3, 4, 6, 7, 5.
• The medication is generally well tolerated, with headache being the most frequently reported adverse event, which is usually mild to moderate and improves with long-term therapy 3, 4, 6, 7, 5.
• There is no evidence of rebound worsening of ischaemia 24 hours after Imdur administration, and no significant difference in response to Imdur and placebo 24 hours after administration 3, 5.