Isosorbide mononitrate is used to prevent chest pain (angina) in patients with a certain heart condition (coronary artery disease). This medication belongs to a class of drugs known as nitrates. It works by relaxing and widening blood vessels so blood can flow more easily to the heart.
This medication will not relieve chest pain once it occurs. Also, it is not intended to be taken just before physical activities (such as exercise or sexual intercourse) to prevent chest pain. Other medications may be prescribed by your doctor for these conditions. Consult your doctor for more details.
OTHER USES: This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
Take this medication by mouth as directed by your doctor, usually once daily when you wake up. Swallow this medication whole with a half glass of water (4 ounces/120 milliliters) unless your doctor directs you otherwise. Do not crush or chew this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split the tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day. Do not stop taking it without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.
Although unlikely, when this medication is used for a long time, it may not work as well and may require different dosing. Tell your doctor if this medication stops working well (for example, you have more frequent or worsening chest pain).
Headache is often a sign that this medication is working. Your doctor may recommend treating headaches with an over-the-counter pain reliever (such as acetaminophen, aspirin). If headaches continue or become severe, tell your doctor promptly.
To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.
An empty tablet shell may appear in your stool. This effect is harmless since your body has already absorbed the medication.
Tell your doctor right away if you have any serious side effects, including: fainting, fast/irregular/pounding heartbeat.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
In the US -
Before taking this medication, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as isosorbide dinitrate, nitroglycerin); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: low blood pressure.
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
Older adults may be more sensitive to the side effects of this medication, especially dizziness and lightheadedness, which could increase the risk of falls.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
Check the labels on all your medicines (such as cough-and-cold products, diet aids, or NSAIDs such as ibuprofen, naproxen) because they may contain ingredients that could worsen symptoms of heart failure. Ask your pharmacist for more details.
Isosorbide mononitrate is very similar to isosorbide dinitrate. Do not use medications containing isosorbide dinitrate while using isosorbide mononitrate.
This medication may interfere with certain laboratory tests (including cholesterol levels), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.
If overdose is suspected, contact a poison control center or emergency room right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: slow heartbeat, vision changes, severe nausea/vomiting, sweating, cold/clammy skin, bluish fingers/toes/lips.
Do not share this medication with others.
Laboratory and/or medical tests (such as blood pressure) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
Lifestyle changes such as dietary changes, exercise, and not smoking may help this drug work better. Talk to your doctor or pharmacist about lifestyle changes that might benefit you.
If you miss a dose, take it as soon as you remember if it is within 6 hours of the missed dose. If it has been longer than 6 hours, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
MEDICAL ALERT: Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).
Information last revised April 2014. Copyright(c) 2014 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet