isosorbide mononitrate



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What is isosorbide mononitrate?

Isosorbide mononitrate is in a group of drugs called nitrates. Isosorbide mononitrate dilates (widens) blood vessels, making it easier for blood to flow through them and easier for the heart to pump.

Isosorbide mononitrate is used to prevent angina attacks (chest pain).

Isosorbide mononitrate will not treat an angina attack that has already begun.

Isosorbide mononitrate may also be used for other purposes not listed in this medication guide.

What is the most important information I should know about isosorbide mononitrate?

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.

Before taking isosorbide mononitrate, tell your doctor if you have congestive heart failure, low blood pressure, kidney disease, or early signs of a heart attack (chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling).

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 the medication. Do not stop taking isosorbide mononitrate. Ask your doctor before using any headache pain medication.

Isosorbide mononitrate will not treat an angina attack that has already begun.

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.

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

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

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

  • early signs of a heart attack (chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling)
  • 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.

Older adults may be more likely to have side effects from this medication.

How should I take isosorbide mononitrate?

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.

Isosorbide mononitrate is usually taken in the morning after getting out of bed. Follow your doctor's instructions.

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.

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

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 other 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.

Store the tablets at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do nottake extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine. An overdose of isosorbide mononitrate can be fatal.

Overdose symptoms may include severe throbbing headache, fever, confusion, dizziness or spinning sensation, nausea, vomiting, vision problems, sweating, fast or pounding heartbeats, cold or clammy skin, trouble breathing, muscle stiffness or paralysis, and seizures (convulsions).

What should I avoid while taking isosorbide mononitrate?

Isosorbide mononitrate can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Avoid drinking alcohol. It can increase some of the side effects of isosorbide mononitrate.

What are the possible side effects of isosorbide mononitrate?

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have any of these serious side effects:

  • fast, slow, pounding, or uneven heart rate
  • feeling like you might pass out
  • trouble breathing; or
  • worsening chest pain.

Less serious side effects may include:

  • headache, dizziness
  • warmth, redness, or tingling under your skin
  • nausea, vomiting, constipation, diarrhea;
  • pain or stiffness in joints or muscles
  • blurred vision; or
  • dry mouth.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect isosorbide mononitrate?

Before taking isosorbide mononitrate, tell your doctor if you are taking any of the following medicines:

  • blood pressure medication
  • dihydroergotamine (D.H.E. 45, Migranal) or ergotamine (Ergomar, Cafergot, and others)
  • an erectile dysfunction medication such as tadalafil (Cialis) or vardenafil (Levitra)
  • a beta-blocker such as atenolol (Tenormin), carvedilol (Coreg), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal), sotalol (Betapace), and others; or
  • a calcium channel blocker such as diltiazem (Tiazac, Cardizem), nifedipine (Procardia), nimodipine (Nimotop), verapamil (Calan, Covera, Verelan), and others.

This list is not complete and there may be other drugs that can interact with isosorbide mononitrate. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Where can I get more information?

Your pharmacist can provide more information about isosorbide mononitrate.


Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.