When to take Isosorbide Dinitrate (Isdn) for angina pectoris management?

From the Guidelines

Isosorbide Dinitrate (ISDN) should be taken 2 to 3 times daily for angina pectoris management, with a dose range of 5 to 80 mg.

Key Points

• The duration of effect of ISDN is up to 8 hours 1.
• ISDN can be taken orally, with or without a slow release formulation, to manage angina symptoms 1.
• It is essential to consider nitrate-free intervals to avoid tolerance development, and other agents like β-blockers and calcium-channel blockers can be used during these intervals 1.
• The management of angina pectoris involves a combination of pharmacotherapy, including aspirin, β-blockers, statins, and ACE inhibitors, to prevent MI and death, and to reduce symptoms 1.
• Sublingual nitroglycerin or nitroglycerin spray can be used for the immediate relief of angina symptoms 1.

From the FDA Drug Label

CLINICAL STUDIES In clinical trials, immediate-release oral isosorbide dinitrate has been administered in a variety of regimens, with total daily doses ranging from 30 mg to 480 mg. Controlled trials of single oral doses of isosorbide dinitrate have demonstrated effective reductions in exercise-related angina for up to 8 hours. Anti-anginal activity is present about 1 hour after dosing Most controlled trials of multiple-dose oral isosorbide dinitrate taken every 12 hours (or more frequently) for several weeks have shown statistically significant anti-anginal efficacy for only 2 hours after dosing. Once-daily regimens, and regimens with one daily dose-free interval of at least 14 hours ( e.g., a regimen providing doses at 0800,1400 and 1800 hours), have shown efficacy after the first dose of each day that was similar to that shown in the single-dose studies cited above. INDICATIONS AND USAGE Isosorbide dinitrate tablets are indicated for the prevention of angina pectoris due to coronary artery disease. The onset of action of immediate-release oral isosorbide dinitrate is not sufficiently rapid for this product to be useful in aborting an acute anginal episode.

The recommended dosing regimen for Isosorbide Dinitrate (ISDN) to manage angina pectoris is to take it at specific times of the day, such as:

• 0800,1400, and 1800 hours, with at least a 14-hour dose-free interval
• Every 12 hours or more frequently, but efficacy is limited to 2 hours after dosing in multiple-dose regimens It is essential to note that ISDN is not suitable for aborting an acute anginal episode due to its slow onset of action, which is about 1 hour after dosing 2 2.

From the Research

Dosage and Administration of Isosorbide Dinitrate for Angina Pectoris

• The optimal dosage and administration schedule of Isosorbide Dinitrate (ISDN) for angina pectoris management is not well established, with various studies suggesting different regimens 3, 4, 5.
• High doses of ISDN (up to 480 mg/day) may be effective in patients who do not respond to low doses (40 mg/day) 3.
• Intermittent injection of ISDN (10 mg/10 min every 2 hours) may be as effective as continuous injection (10 mg/h) in patients with unstable angina 6.
• Asymmetric dosing regimens, such as bid or tid, may help reduce the development of tolerance to ISDN 4.
• The use of controlled-release formulations of ISDN may provide sustained antianginal effects, but further studies are needed to establish useful dosing regimens 4.

Timing of ISDN Administration

• ISDN can be taken as needed for angina attacks, with some studies suggesting that it can be taken up to 4 times a day 3, 4.
• The timing of ISDN administration may depend on the individual patient's response to the medication and their daily activities 4, 7.
• Some patients may require higher than recommended doses of ISDN to achieve relief from angina symptoms, but this should be done under medical supervision 7.

Considerations for ISDN Use

• Tolerance to ISDN can develop with continuous use, and a nitrate-free interval may be necessary to maintain its effectiveness 5.
• ISDN can cause side effects such as headache and hypotension, and patients should be monitored for these effects 7.
• The use of ISDN should be individualized based on the patient's response to the medication and their underlying medical condition 3, 6, 4, 5, 7.