Prescribing-label excerpts
Nitroglycerin
Reference for: Nitroglycerin. Source presentation: spray. Source route: oral.
The cited studies use standard-release spray. The catalogue entry has a different or unspecified release description; these study values do not establish its absorption profile.
Mechanism of action
Nitroglycerin forms free radical nitric oxide (NO), which activates guanylate cyclase, resulting in an increase of guanosine 3',5'-monophosphate (cyclic GMP) in smooth muscle and other tissues. This eventually leads to dephosphorylation of myosin light chains, which regulates the contractile state in smooth muscle and results in vasodilatation.
Pharmacokinetics
A liver reductase enzyme is of primary importance in the metabolism of nitroglycerin to glycerol di- and mononitrate metabolites and ultimately to glycerol and organic nitrate. Known sites of extrahepatic metabolism include red blood cells and vascular walls. In addition to nitroglycerin, 2 major metabolites, 1,2- and 1,3-dinitroglycerin are found in plasma. The mean elimination half-life of both 1,2- and 1,3-dinitroglycerin is about 40 minutes. The 1,2- and 1,3-dinitroglycerin metabolites have been reported to possess some pharmacological activity, whereas the glycerol mononitrate metabolites of nitroglycerin are essentially inactive. Higher plasma concentrations of the dinitro metabolites, with their nearly 8-fold longer elimination half-lives, may contribute significantly to the duration of pharmacologic effect.
In a pharmacokinetic study when a single 0.8 mg dose of Nitroglycerin Lingual Spray was administered to healthy volunteers (n = 24), the mean C max and t max were 1,041 pg/ml and 7.5 minutes, respectively. Additionally, in these subjects the mean area under the curve (AUC) was 12,769 pg/ml * min.
The volume of distribution of nitroglycerin following intravenous administration is 3.3 L/kg.
Drug interactions — Aspirin: Coadministration of nitroglycerin with high dose aspirin (1000 mg) results in increased exposure to nitroglycerin. The vasodilatory and hemodynamic effects of nitroglycerin may be enhanced by concomitant administration of nitroglycerin with high dose aspirin.
Tissue-type plasminogen activator (t-PA): Concomitant administration of t-PA and intravenous nitroglycerin has been shown to reduce plasma levels of t-PA and its thrombolytic effect.
Selected passages from the cited U.S. prescribing label. The studies concern the source product and populations named in each passage; they do not establish Walter-product bioequivalence, an approved indication, or the kinetics of another fixed combination. Tables and the full prescribing information remain available in the source.
Source: DailyMed: Nitroglycerin — spray
Reference accessed . Label revision: 2025-12-17.