• In chronic dosing, duration of effect is much shorter due to tolerance
Drug Onset of action Duration of effect
spray and tablet
1 - 3 minutes around 25 minutes
Isosorbide dinitrate about 1 hour up to 8 hours
after one dose
Isosorbide mononitrate about 1 hour up to 12 hours
after one dose
Nitroglycerin ointment not rapid enough
for acute angina
up to 12 hours
Nitroglycerin patch steady-state
reached in 2 hours
up to 12 hours