Key takeaways
Isosorbide mononitrate (Monoket) and isosorbide dinitrate (Isordil) are both nitrate vasodilators used to treat angina, but they have some key differences. Isosorbide mononitrate is available in both immediate-release (IR) and extended-release (ER) forms, with the IR taken twice daily and the ER taken once daily. In contrast, isosorbide dinitrate is available as a short-acting tablet taken 2 or 3 times daily and a long-acting capsule, which is only available as a brand name and can be more expensive. Isosorbide mononitrate generally lasts longer, with IR tablets lasting 6 to 10 hours, while isosorbide dinitrate's short-acting tablets last 4 to 6 hours. Both medications can cause headaches and dizziness, and you should avoid alcohol and erectile dysfunction medications while taking them. However, isosorbide mononitrate has a generic version available for both its IR and ER forms, making it potentially more affordable.
