Isosorbide dinitrate

Isosorbide dinitrate is a nitrate that widens blood vessels, helping blood flow more easily and making it easier for the heart to pump.

Isosorbide dinitrate is used to treat or prevent chest pain attacks (angina).

Only the sublingual tablet should be used to treat an angina attack that has already started.

Isosorbide dinitrate regular and extended-release tablets are used to prevent angina attacks but will not treat an angina attack.

Isosorbide dinitrate may also be used for reasons not mentioned in this medication guide.

Before using isosorbide dinitrate to treat a sudden angina attack, your doctor may want you to first use a nitroglycerin sublingual tablet. Follow your doctor's instructions about which medications to use during an attack and how much time to allow between doses.

Follow all directions on your prescription label. Your doctor may occasionally change your dose. Do not take this medicine in larger or smaller amounts or for longer than recommended. If you use too much isosorbide dinitrate, it might stop working as well in controlling your condition.

Try to rest or stay seated when you take this medicine (may cause dizziness or fainting).

To prevent angina attacks, isosorbide dinitrate is usually taken at regular intervals.

To treat an angina attack that has already begun, use the medicine at the first sign of chest pain. Place the tablet under your tongue and allow it to dissolve slowly. Do not chew or swallow it.

You may use the sublingual tablet within 15 minutes before an activity you think might cause chest pain. Follow your doctor's instructions.

Do not crush, chew, break, or open an extended-release capsule or tablet. Swallow it whole.

Follow your doctor's dosing instructions very carefully. If your doctor changes your brand, strength, or type of isosorbide dinitrate, your dosage needs may change. Ask your pharmacist if you have any questions about the new kind of isosorbide dinitrate you receive at the pharmacy.

Seek emergency medical attention if your chest pain gets worse or lasts longer than 5 minutes, especially if you have trouble breathing or feel weak, dizzy, nauseated, or lightheaded.

You may have very low blood pressure while taking this medicine. Call your doctor if you are sick with vomiting or diarrhea, or if you are sweating more than usual. Prolonged illness can lead to a serious electrolyte imbalance, making it dangerous for you to use isosorbide dinitrate.

If you take isosorbide dinitrate on a regular schedule to prevent angina, do not stop taking it suddenly or you could have a severe attack of angina. Keep this medicine on hand at all times. Get your prescription refilled before you run out of medicine completely.

Store at room temperature, away from moisture, heat, and light. Keep the bottle tightly closed when not in use.

You should not take erectile dysfunction medicine (Viagra, Cialis, Levitra, Stendra, Staxyn, sildenafil, avanafil, tadalafil, vardenafil) while you are taking isosorbide dinitrate. Taking these medicines together can cause a sudden and serious drop in blood pressure.

Seek emergency medical help if you have early signs of a heart attack (chest pain or pressure, pain spreading to your jaw or shoulder, sweating, feeling generally unwell).

You should not use isosorbide dinitrate if:

• you are allergic to isosorbide dinitrate, isosorbide mononitrate, or nitroglycerin; or
• you have early signs of a heart attack (chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating).

You should not take erectile dysfunction medicine (Viagra, Cialis, Levitra, Stendra, Staxyn, sildenafil, avanafil, tadalafil, vardenafil) while you are taking isosorbide dinitrate. Taking these medicines together can cause a sudden and serious decrease in blood pressure.

To make sure isosorbide dinitrate is safe for you, tell your doctor if you have:

• congestive heart failure;
• kidney disease; or
• low blood pressure.

It is not known whether isosorbide dinitrate will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether isosorbide dinitrate passes into breast milk or if it could affect the nursing baby. Tell your doctor if you are breast-feeding.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Isosorbide dinitrate may cause serious side effects. Call your doctor right away if you have:

• a light-headed feeling, like you might pass out;
• worsening angina pain;
• fast or slow heart rate; or
• pounding heartbeats or fluttering in your chest.

Isosorbide dinitrate can cause severe headaches. These headaches may gradually become less severe as you continue to use nitroglycerin. Do not stop taking isosorbide dinitrate to avoid headaches. Ask your doctor before using any headache pain medication.

Common side effects may be more likely to occur, such as:

• headache; or
• flushing (warmth, redness, or tingly feeling).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Since isosorbide dinitrate is sometimes used only as needed, you may not have a regular dosing schedule. If you do have a schedule and miss a dose, take it as soon as you remember. If your next dose is less than 2 hours away, skip the missed dose.

If you are using the extended-release capsule or tablet and your next dose is less than 6 hours away, skip the missed dose and take the medicine at your next scheduled time.

Do not use extra medicine to make up for a missed dose.

Seek emergency medical help if you think you have taken too much isosorbide dinitrate. An overdose of isosorbide dinitrate can be deadly.

Signs of overdose may include a severe throbbing headache, fever, confusion, severe dizziness, fast or pounding heartbeats, vision issues, nausea, vomiting, stomach pain, bloody diarrhea, trouble breathing, sweating, cold or clammy skin, fainting, and seizures (convulsions).

This medicine may affect your thinking or reactions. Be careful if you drive or do anything that needs you to be alert. Avoid standing up too quickly from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to avoid falling.

Avoid drinking alcohol. Alcohol may increase some side effects of isosorbide dinitrate (dizziness, drowsiness, feeling light-headed, or fainting).

Taking isosorbide dinitrate with certain other medicines can cause dangerously low blood pressure. This includes medicines for erectile dysfunction or pulmonary arterial hypertension. Serious, life-threatening side effects may happen.

Tell your doctor about all your current medicines and any that you start or stop using, especially:

• avanafil (Stendra);
• a diuretic or "water pill";
• nitroglycerin;
• riociguat (Adempas);
• sildenafil (Viagra, Revatio);
• tadalafil (Cialis, Adcirca); or
• vardenafil (Levitra, Staxyn).

This list is not complete. Other drugs may interact with isosorbide dinitrate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are included in this medication guide.