Also known as: Isosorbide
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.
This section provides information on the proper use of a number of products that contain isosorbide mononitrate. It may not be specific to Imdur ER. Please read with care.
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.
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.
For prevention of angina: For oral dosage form (extended-release tablets): Adults—At first, 30 or 60 milligrams (mg) once a day. Take the dose in the morning right after you wake up. Your doctor may increase your dose as needed. Children—Use and dose must be determined by your doctor. For oral dosage form (tablets): Adults—20 milligrams (mg) two times a day. Take the first dose in the morning right after you wake up, and the second dose 7 hours later. Children—Use and dose must be determined by your doctor.
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).
Store at room temperature between 15 and 30 degrees C (59 and 86 degrees F) away from moisture and heat. Keep container tightly closed. Throw away any unused medicine after the expiration date. Keep out of the reach of children.