Consumer Drug Information

Imdur

Generic Name: isosorbide mononitrate (EYE soe SOR bide MON oh NYE trate)
Brand Names: Imdur, ISMO, Monoket

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?

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.

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.

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 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.

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.

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 not take 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 a severe throbbing headache, fever, confusion, dizziness or spinning sensation, fast or pounding heartbeats, vision problems, nausea, vomiting, stomach pain, bloody diarrhea, trouble breathing, sweating, cold or clammy skin, feeling light-headed, fainting, and seizure (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.

Isosorbide mononitrate side effects

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 a serious side effect such as:

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

Less serious side effects may include:

headache, mild dizziness;
warmth, redness, or tingling under your skin;
nausea, vomiting, constipation, diarrhea;
pain or stiffness in joints or muscles;
hot flashes; 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?

Tell your doctor about all other medications you use, especially:

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, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others; or
a calcium channel blocker such as diltiazem (Cartia, Cardizem), felodipine (Plendil), nifedipine (Nifedical, Procardia), verapamil (Calan, Covera, Isoptin, 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.