• Pronunciation: EYE soe SOR bide dye NYE trate
  • Brand: Dilatrate-SR, Isochron, Isordil Titradose

What is the most important information I should know about Isordil?

Do not use Isordil if you are taking sildenafil (Viagra). Serious, life-threatening side effects can occur if you take Isordil while you are using sildenafil.

You should not use this medication if you are allergic to Isordil, isosorbide mononitrate (Imdur, ISMO, Monoket), or nitroglycerin, or if you have early signs of a heart attack (chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling).

Before taking Isordil, tell your doctor if you have congestive heart failure, low blood pressure, or kidney disease.

Isordil can cause severe headaches, especially when you first start using it. These headaches may gradually become less severe as you continue to use the medication. Do not stop taking Isordil. Ask your doctor before using any headache pain medication.

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

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

It is important to keep taking this medicine as directed to prevent an angina attack. Get your prescription refilled before you run out of medicine completely.

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

What is Isordil?

Isordil is in a group of drugs called nitrates. Isordil dilates (widens) blood vessels, making it easier for blood to flow through them and easier for the heart to pump.

Isordil is used to treat or prevent attacks of chest pain (angina).

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

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

Isordil may also be used for purposes other than those listed in this medication guide.

What should I discuss with my healthcare provider before taking Isordil?

Do not use Isordil if you are taking sildenafil (Viagra). Serious, life-threatening side effects can occur if you take Isordil while you are using sildenafil.

You should not use this medication if you are allergic to Isordil, isosorbide mononitrate (Imdur, ISMO, Monoket), or nitroglycerin, or if you have early signs of a heart attack (chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling).

If you have any of these other conditions, you may need a dose adjustment or special tests to safely take Isordil:

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

FDA pregnancy category C. It is not known whether Isordil is harmful to an unborn baby. Before you take this medication, tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether Isordil passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

Isordil can cause severe headaches, especially when you first start using it. These headaches may gradually become less severe as you continue to use Isordil. Do not stop taking the medication. Ask your doctor before using any headache pain medication.

How should I take Isordil?

Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

Your doctor may occasionally change your dose to make sure you get the best results from this medication. Isordil is usually taken 2 or 3 times per day. Follow your doctor’s dosing instructions very carefully.

If possible, try to rest or stay seated when you use this medication. Isordil can cause dizziness or fainting.

Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow the pill whole. Breaking the pill may cause too much of the drug to be released at one time.

If you expect to engage in an activity that may cause angina, take the sublingual tablet about 15 minutes before the activity.

If you use the sublingual tablet 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.

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

Some things can cause your blood pressure to get too low. This includes vomiting, diarrhea, heavy sweating, heart disease, dialysis, a low-salt diet, or taking diuretics (water pills). Tell your doctor if you have a prolonged illness that causes diarrhea or vomiting.

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

It is important to keep this medicine on hand at all times in case of an angina attack. Get your prescription refilled before you run out of medicine completely.

If you take Isordil on a regular schedule to prevent angina, do not stop taking it suddenly or you could have a severe attack of angina.

Do not change brands of Isordil without the approval of your doctor.

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

What happens if I miss a dose?

Since Isordil is sometimes used only when needed, you may not be on a dosing schedule. If you are using the medication regularly, use the missed dose as soon as you remember. If your next dose is less than 2 hours away, skip the missed dose and use the medicine at your next regularly scheduled time.

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

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

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine. An overdose of Isordil can be fatal.

Overdose symptoms may include a severe throbbing headache, fever, confusion, dizziness or spinning sensation, fast or pounding heartbeats, vision problems, nausea, vomiting, stomach pain, bloody diarrhea, trouble breathing, sweating, cold or clammy skin, feeling light-headed, fainting, and seizure (convulsions).

What should I avoid while taking Isordil?

Isordil can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Avoid drinking alcohol. It can increase some of the side effects of Isordil.

What are the possible side effects of Isordil?

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

Call your doctor at once if you have a serious side effect such as:

  • fast, slow, pounding, or uneven heart rate;
  • worsening angina pain;
  • blurred vision or dry mouth;
  • nausea, vomiting, sweating, pale skin, feeling like you might pass out; or
  • blue-colored skin, tiredness, and feeling short of breath.

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

  • headache, mild dizziness;
  • weakness; 
  • warmth, redness, or tingly feeling under your skin.

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.

What other drugs will affect Isordil?

Tell your doctor about all other medications you use, especially:

  • blood pressure medication;
  • dihydroergotamine (D.H.E. 45, Migranal) or ergotamine (Ergomar, Cafergot, and others);
  • an erectile dysfunction medication such as tadalafil (Cialis) or vardenafil (Levitra);
  • a beta-blocker such as atenolol (Tenormin, Tenoretic), carvedilol (Coreg), labetalol (Normodyne, Trandate), metoprolol (Lopressor, Toprol), nadolol (Corgard), propranolol (Inderal, InnoPran), sotalol (Betapace), and others; 
  • a calcium channel blocker such as diltiazem (Cartia, Cardizem), felodipine (Plendil), nifedipine (Nifedical, Procardia), verapamil (Calan, Covera, Isoptin, Verelan), and others.

This list is not complete and there may be other drugs that can interact with Isordil. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.