Comparative hemodynamic study of IS-5-MN and ISDN in man--which are equieffective doses?

Area of Science:

• Cardiology
• Pharmacology
• Hemodynamics

Background:

• Myocardial infarction (MI) can lead to significant hemodynamic alterations.
• Nitrates are commonly used to manage cardiovascular conditions, including post-MI.
• Understanding the comparative hemodynamic effects of different nitrate formulations is crucial for optimizing patient care.

Purpose of the Study:

• To compare the hemodynamic effects of sustained release isosorbide dinitrate (ISDN) and isosorbide-5-mononitrate (IS-5-MN) in patients post-MI.
• To assess the magnitude and time course of hemodynamic changes induced by these two nitrate formulations.

Main Methods:

• A crossover study design was employed.
• Ten patients who had experienced myocardial infarction were included.
• Hemodynamic parameters, specifically cardiac preload, were measured after administration of 40 mg of sustained release ISDN and 40 mg of IS-5-MN.

Main Results:

• No significant difference was observed in the magnitude of the effect on cardiac preload between sustained release ISDN and IS-5-MN.
• The onset of hemodynamic effect was faster with IS-5-MN compared to sustained release ISDN.
• The time to reach the nadir of the effect was also shorter for IS-5-MN.

Conclusions:

• Both sustained release isosorbide dinitrate and isosorbide-5-mononitrate are hemodynamically equieffective when administered in equal doses (40 mg) in patients post-myocardial infarction.
• Despite equivalent efficacy in magnitude, their onset and duration of action differ, with IS-5-MN exhibiting a faster onset and earlier peak effect.