The most common side effects of Isosorbide mononitrate are headache, dizziness, lightheadedness, nausea, and flushing. These will generally go away as your body adjusts to the medication. A headache is often a sign that the medication is working and your doctor may recommend treatment with over-the-counter pain relievers such as acetaminophen or aspirin. Tell your doctor if the headaches are severe or don’t go away.
To minimize lightheadedness and dizziness, stand up slowly.
Severe adverse reactions to Isosorbide mononitrate are rare, but can occur. Tell your doctor right away if you have any serious problems or allergic reactions to this medication.
This is not a complete list of side effects. For more information regarding precautions and possible side effects, please visit the National Institutes of Health’s DailyMed page for Isosorbide Mononitrate.