Take isosorbide mononitrate exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not take this medicine in larger or smaller amounts or for longer than recommended. If you use too much isosorbide mononitrate, it might stop working as well in controlling your condition.
Try to rest or stay seated when you take this medicine (may cause dizziness or fainting).
Do not crush, chew, or break an extended-release tablet. Swallow it whole.
Not all brands and forms of isosorbide mononitrate are taken the same number of times per day. You may need to take the medicine only once daily, in the morning after getting out of bed. You may also need a second dose later in the day.
Follow your doctor's dosing instructions very carefully. If your doctor changes your brand, strength, or type of isosorbide mononitrate, your dosage needs may change. Ask your pharmacist if you have any questions about the new brand of medicine you receive at the pharmacy.
Use this medicine regularly to prevent an angina attack. Get your prescription refilled before you run out of medicine completely.
You should not stop using isosorbide mononitrate suddenly or you could have a severe attack of angina. Keep this medicine on hand at all times. Get your prescription refilled before you run out of medicine completely.
Store at room temperature away from moisture, heat, and light. Keep the bottle tightly closed when not in use.
 Detailed Isosorbide mononitrate dosage information
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of isosorbide mononitrate can be fatal.
Overdose symptoms may include a severe throbbing headache, fever, confusion, severe dizziness, fast or pounding heartbeats, vision problems, nausea, vomiting, stomach pain, bloody diarrhea, trouble breathing, sweating, cold or clammy skin, fainting, and seizure (convulsions).
