• Use isosorbide mononitrate exactly as directed. Follow your doctor\\\'s instructions, especially about the timing of your doses. Your blood needs to be free of isosorbide mononitrate for a certain period every day.
• You may develop a headache because of this medicine, but do not stop taking it. Take aspirin or acetaminophen to treat the headache. Ask your doctor which is best for you. This side effect usually goes away as treatment with isosorbide mononitrate continues.
• Do not stop taking isosorbide mononitrate
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• Isosorbide mononitrate is in a class of drugs called nitrates. Isosorbide mononitrate dilates (widens or relaxes) blood vessels (arteries and veins). When blood vessels are dilated, it is easier for the heart to pump. Also, more blood, which is rich in oxygen, can flow to the heart.
• Isosorbide mononitrate is used to prevent angina attacks (chest pain).
• Isosorbide mononitrate may also be used for purposes other than those listed in this medication guide.

Before taking isosorbide mononitrate, tell your doctor if youˇ have had a heart attack

• have congestive heart failure
• have low blood pressure;
• have had a stroke, a transient ischemic attack (TIA, or mini-stroke), or a serious head injury;
• have anemia;
• have an allergy to nitrates;
• have closed-angle glaucoma;
• suffer from migraines;
• have kidney disease; or
• have liver disease.

• Take isosorbide mononitrate exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.
• Take each dose with a full glass of water.
• Isosorbide mononitrate is usually taken first thing in the morning before breakfast. Follow your doctor\\\'s instructions.
• Swallow the extended-release forms of isosorbide mononitrate whole. Do not crush or chew them. They are specially formulated to release medication slowly into your
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If you experience any of the following serious side effects, stop taking isosorbide mononitrate and seek emergency medical attention:

• an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);
• blurred vision or dry mouth; or
• irregular heartbeat;
• fainting.

Other, less serious side effects may be more likely to occur. Continue to take isosorbide mononitrate and talk to your doctor if you experience

• headache or dizziness,
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Do not use sildenafil (Viagra), a drug used to treat impotence, while taking isosorbide mononitrate. The combination could cause severe or life-threatening low blood pressure.

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

• dihydroergotamine (D.H.E. 45); or
• any other heart medicines, especially those used to treat high blood pressure or irregular heartbeats.