isosorbide mononitrate

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 suddenly. Stopping suddenly could cause a severe angina (chest pain) attack.

Do not drink alcohol while taking this medication.

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 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 this medication, tell your doctor if you

• 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.

The conditions listed above may prevent you from taking isosorbide or you may need a dosage adjustment or special monitoring during your therapy.

Isosorbide mononitrate is in the FDA pregnancy category C. This means that it is not known whether it will harm an unborn baby. Do not take isosorbide mononitrate without first talking to your doctor if you are pregnant.

It is also not known whether isosorbide passes into breast milk. Do not take isosorbide mononitrate without first talking to your doctor if you are breast-feeding a baby.

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 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 body.

Do not stop taking isosorbide mononitrate suddenly. Stopping suddenly could cause a severe angina attack.

Store the tablets at room temperature away from moisture and heat. Isosorbide mononitrate tablets must be stored in the container that your pharmacist gives them to you in. Throw away any leftover isosorbide mononitrate on the expiration date. Expired isosorbide will not treat your condition.

Take the missed dose as soon as you remember. If you are taking the regular tablets (not the extended-release tablets) and your next regularly scheduled dose is within 2 hours, skip the dose you missed and take only your next regularly scheduled dose. If you are taking the extended release tablets and your next regularly scheduled dose is within 6 hours, also skip the missed dose and take only your next regularly scheduled dose. Do not take a double dose of this medication.

Seek emergency medical attention.

Symptoms of an isosorbide mononitrate overdose include a severe throbbing headache, difficult or slow breathing, muscle cramps, nausea, vomiting, diarrhea, fever, dizziness, fainting, an irregular heartbeat, changes in vision, flushing, and seizures.

Use caution when driving, operating machinery, or performing other hazardous activities. Also, stand up slowly from a sitting or lying position. Isosorbide mononitrate may cause dizziness. If you experience dizziness, avoid hazardous activities.

Avoid alcohol. It also widens your blood vessels and it can cause very low blood pressure, dizziness and drowsiness and you could endanger yourself or others.

Do not stop taking isosorbide mononitrate suddenly.

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 and talk to your doctor if you experience

• headache or dizziness,
• flushing (redness of the face, neck, and chest),
• nausea or vomiting,
• a fast heartbeat,
• swollen ankles, or
• weakness.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

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.

You may require a dosage adjustment or special monitoring during your treatment if you are taking any of the medicines listed above.

Do not drink alcohol. Like isosorbide mononitrate, alcohol widens your blood vessels, and it can cause very low blood pressure, dizziness, and drowsiness. If you combine isosorbide mononitrate and alcohol, you could endanger yourself or others.

Drugs other than those listed here may also interact with isosorbide mononitrate or affect your condition. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines.

Your pharmacist has additional information about isosorbide mononitrate written for health professionals that you may read.

Isosorbide mononitrate is available with a prescription generically and under several brand names. Ask your pharmacist any questions you have about this medication, especially if it is new to you.