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In this Article

• What is isosorbide mononitrate (Ismo)?
• What are the possible side effects of isosorbide mononitrate (Ismo)?
• What is the most important information I should know about isosorbide mononitrate (Ismo)?
• What should I discuss with my healthcare provider before taking isosorbide mononitrate (Ismo)?
• How should I take isosorbide mononitrate (Ismo)?
• What happens if I miss a dose (Ismo)?
• What happens if I overdose (Ismo)?
• What should I avoid while taking isosorbide mononitrate (Ismo)?
• What other drugs will affect isosorbide mononitrate (Ismo)?
• Where can I get more information?

What should I discuss with my healthcare provider before taking isosorbide mononitrate (Ismo)?

Do not use isosorbide mononitrate if you are taking sildenafil (Viagra). Serious, life-threatening side effects can occur if you take isosorbide mononitrate while you are using sildenafil.

You should not use this medication if you are allergic to isosorbide mononitrate, isosorbide dinitrate, (Isordil, Dilatrate, Isochron), or nitroglycerin, or if you have early signs of a heart attack (chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling).

If you have any of these other conditions, you may need a dose adjustment or special tests to safely take isosorbide mononitrate:

• congestive heart failure;
• low blood pressure; or
• kidney disease.

FDA pregnancy category B. Isosorbide mononitrate is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether isosorbide mononitrate passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Isosorbide mononitrate can cause severe headaches, especially when you first start using it. These headaches may gradually become less severe as you continue to use isosorbide mononitrate. Do not stop taking the medication. Ask your doctor before using any headache pain medication.

How should I take isosorbide mononitrate (Ismo)?

Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results from this medication.

Not all brands and forms of isosorbide mononitrate are taken the same number of times per day. You may need to take the medication only once daily, in the morning after getting out of bed. Or you may need a second dose later in the day. Follow your doctor's dosing instructions very carefully.

If possible, try to rest or stay seated when you use this medication. Isosorbide mononitrate can cause dizziness or fainting.

Take this medication with at least 4 ounces of water or other liquid.

Do not crush, chew, or break an extended-release tablet. Swallow the pill whole. Breaking the pill may cause too much of the drug to be released at one time.

This medication can cause you to have unusual results with certain medical tests. Tell any doctor who treats you that you are using isosorbide mononitrate.

Some things can cause your blood pressure to get too low. This includes vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low-salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.

It is important to keep taking this medicine as directed to prevent an angina attack. Get your prescription refilled before you run out of medicine completely.

Do not stop taking isosorbide mononitrate suddenly. Stopping suddenly could cause a severe angina attack.

Do not change brands of isosorbide mononitrate without the approval of your doctor.

Store isosorbide mononitrate at room temperature, away from moisture, heat, and light. Keep the bottle tightly closed when not in use.