Generic Name: isosorbide dinitrate

Brand name(s): Dilatrate-SR, Isordil Titradose

Isosorbide dinitrate is used to treat or prevent the symptoms of angina (chest pain). It works by relaxing and widening blood vessels in certain areas of your body, which decreases the work your heart has to do. This medicine will not cure your angina, but it will help you have fewer and less severe attacks. Isosorbide dinitrate may also be used for purposes not listed in this medication guide.

You should not use isosorbide dinitrate if you are allergic to it, or if:

  • you have had a heart attack within the past 2 weeks;
  • you have unstable angina;
  • you have high blood pressure that is not controlled with medication; or
  • you are taking certain other medicines such as disulfiram (Antabuse).

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

  • congestive heart failure;
  • low blood pressure;
  • a lightheaded feeling, like you, might pass out; or
  • Raynaud’s syndrome.

Do not take this medicine if you are pregnant. Isosorbide dinitrate could harm the unborn baby. Tell your doctor if you become pregnant during treatment.

It is not known whether isosorbide dinitrate passes into breast milk or if it could harm a nursing baby. You should not breastfeed while using this medicine.

Do not give this medicine to anyone under 18 years old.

Isosorbide dinitrate is not approved for use by anyone younger than 18 years old.

Warnings/Precautions

Before taking this medicine,

tell your doctor or pharmacist if you are allergic to it; 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.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: low blood pressure, a recent heart attack, or certain types of heart disease (e.g., severe left ventricular outflow obstruction, unstable angina).

This medicine may cause drowsiness. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.

Pharmacokinetics

After oral administration, isosorbide dinitrate is rapidly and completely absorbed with peak plasma concentrations achieved within 30-60 minutes. Steady-state levels are reached within 3 days of once or twice daily dosing. Isosorbide dinitrate is highly bound to plasma proteins (approximately 96%).

The elimination half-life of isosorbide dinitrate ranges from 1.5 to 3 hours. Plasma clearance is approximately 0.6 L/kg/hr with the majority of the drug being excreted in urine (70%) as metabolites. Less than 5% of an oral dose of isosorbide dinitrate is recovered unchanged in the urine.

Side Effects

Dizziness, headache, lightheadedness, tired feeling, or flushing (warmth, redness, or tingly feeling) may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. To relieve dizziness or lightheadedness when rising from a seated or lying position, get up slowly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor right away if you have any serious side effects, including fainting. 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, or trouble breathing. This is not a complete list of possible side effects.

Dosage and Administration

Isosorbide dinitrate may be administered orally with or without food.

The usual adult dosage is: 5 mg to 20 mg (1 to 4 tablets) 4 times a day. The total daily dose should not exceed 80 mg.

For prophylactic therapy, the usual adult dosage is 5 mg to 10 mg (1 or 2 tablets) 3 or 4 times daily. The total daily dose should not exceed 40 mg.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses. Storage

Overdose

In case of overdose, call the poison control helpline. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed or is not breathing, call local emergency services at 999.

Symptoms of overdose may include:

  • slow heartbeat
  • fainting
  • feeling lightheaded or dizzy
  • chest pain or tightness
  • shortness of breath

Storage

Store at room temperature away from light and moisture. Do not store it 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 for more details about how to safely discard your product.

For Isordil Titradose: Store at 25°C (77°F); excursions permitted to 15–30°C (59–86°F)

Isordil 10 mg sublingual tablets: Store at 20–25°C (68–77°F); excursions permitted to 15–30°C (59–86°F)