Comparative Pharmacology
Head-to-head clinical analysis: ISORDIL versus NITROMIST.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ISORDIL versus NITROMIST.
ISORDIL vs NITROMIST
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Isosorbide dinitrate is converted to nitric oxide (NO) in vascular smooth muscle, activating guanylate cyclase, increasing cGMP, leading to vasodilation of veins (greater effect) and arteries. Reduces preload and afterload, decreasing myocardial oxygen demand.
Nitroglycerin is a prodrug that releases nitric oxide (NO) which activates guanylyl cyclase, increasing cGMP in smooth muscle cells, leading to vasodilation primarily of venous capacitance vessels and coronary arteries.
Isosorbide dinitrate: initial 5-20 mg orally 2-3 times daily, maintenance 10-40 mg orally 2-3 times daily. Sublingual: 2.5-5 mg every 15 minutes for up to 3 doses for acute angina. Extended-release: 40 mg orally once daily, increased to 80 mg once daily as tolerated.
1-2 sprays (0.4-0.8 mg) sublingually or intraorally at onset of angina, may repeat every 5 minutes up to 3 doses. Prophylaxis: 1 spray (0.4 mg) 5-10 minutes before activity.
None Documented
None Documented
Terminal half-life: 1–4 hours (isosorbide dinitrate); clinical context: short duration requires frequent dosing or sustained-release formulations.
2–3 minutes for nitroglycerin; rapid metabolism results in short terminal half-life. Clinically, effects dissipate within 30 minutes of discontinuation.
Renal: 80% as inactive metabolites; biliary/fecal: 20% as conjugates.
Renal excretion of inactive metabolites accounts for >80% of elimination; biliary/fecal excretion is minimal (<15%).
Category C
Category C
Nitrate Vasodilator
Nitrate Vasodilator