Correlation between isosorbide dinitrate plasma levels and coronary vasodilation after chewing capsules

Area of Science:

• Cardiology
• Pharmacology

Background:

• Coronary artery disease (CAD) necessitates effective treatments for angina relief and improved diagnostic procedures.
• Sublingual isosorbide dinitrate (ISDN) is a common vasodilator, but its efficacy with novel delivery methods requires investigation.

Purpose of the Study:

• To evaluate the efficacy of ISDN chewing capsules in dilating epicardial coronary arteries in patients with CAD.
• To assess the pharmacokinetic profile of ISDN and its metabolite, isosorbide mononitrate, following administration.
• To determine the correlation between ISDN plasma levels and coronary artery dilation.

Main Methods:

• Coronary angiography was performed on 10 CAD patients before and at 5, 10, and 15 minutes after administering two 5 mg ISDN chewing capsules.
• Blood samples were analyzed using gas chromatography to measure ISDN and isosorbide mononitrate plasma levels.
• Coronary artery diameters were measured using the CAAS automated edge detection system.

Main Results:

• Mean coronary artery diameters increased significantly (p < 0.001) by 20-27% at 5, 10, and 15 minutes post-administration.
• ISDN plasma levels peaked at 5 minutes (138 ng/ml) and decreased over time.
• Significant dilation of coronary stenoses (up to 98%) was observed in seven patients.

Conclusions:

• ISDN chewing capsules provide potent and sustained dilation of epicardial coronary arteries.
• This delivery method may be advantageous for rapid and prolonged relief of anginal symptoms.
• ISDN chewing capsules can enhance coronary artery visualization during angiography.