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Imdur ER (Oral)

Generic name: isosorbide mononitrate [ eye-soe-SOR-bide-mon-oh-NYE-trate ]
Brand names: Imdur, Imdur ER, Ismo, Monoket
Drug class: Antianginal agents

Medically reviewed by Drugs.com. Last updated on Aug 6, 2024.

Uses for Imdur ER

Isosorbide mononitrate is used to prevent angina (chest pain) caused by coronary artery disease (heart disease). It does not work fast enough to relieve the pain of an angina attack that has already started.

Isosorbide mononitrate belongs to the group of medicines called nitrates. It works by relaxing the blood vessels and increasing the supply of blood and oxygen to the heart while reducing its workload. When used regularly on a long-term basis, this helps prevent angina attacks from occurring.

This medicine is available only with your doctor's prescription.

Before using Imdur ER

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of isosorbide mononitrate in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of isosorbide mononitrate in the elderly. However, elderly patients are more likely to have severe low blood pressure and age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving isosorbide mononitrate.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper use of Imdur ER

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This form of nitrate is used to reduce the number of angina attacks over a long time. It will not relieve an attack that has already started because it works too slowly. The extended-release form gradually releases medicine to provide its effect for 8 to 10 hours. Check with your doctor if you also need a fast-acting medicine to relieve the pain of an angina attack.

You should take this medicine first thing in the morning and follow the same schedule each day. This medicine works best if you have a "drug-free" period of time every day when you do not take it. Your doctor will schedule your doses during the day to allow for a drug-free time. Follow the schedule of dosing carefully so the medicine will work properly.

Swallow the extended-release tablet whole with a half glass of water. Do not split, crush, or chew it.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

amlodipine, lisinopril, aspirin, metoprolol, furosemide, carvedilol, spironolactone, atenolol, propranolol, diltiazem

Precautions while using Imdur ER

If you will be taking this medicine for a long time, it is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Do not take riociguat (Adempas®), sildenafil (Viagra®), tadalafil (Cialis®), or vardenafil (Levitra®) while you are using this medicine. Using these medicines together may lower your blood pressure and cause blurred vision, dizziness, lightheadedness, or fainting. If you are taking these medicines and you experience an angina attack, you must go to the hospital right away.

This medicine may cause headaches. These headaches are a sign that the medicine is working. Do not stop using the medicine or change the time you use it in order to avoid the headaches. If you have severe pain, talk with your doctor.

Dizziness, lightheadedness, or faintness may occur, especially when you get up quickly from a lying or sitting position. Getting up slowly may help.

Dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. While you are taking this medicine, be careful to limit the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.

Do not stop using this medicine without checking first with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before you have medical tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects of Imdur ER

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

Rare

Get emergency help immediately if any of the following symptoms of overdose occur:

Symptoms of overdose

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Antianginal

Chemical Class: Nitrate

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.