Isosorbide Dinitrate (Oral, Sublingual)


Isosorbide dinitrate is a drug used in the prevention of angina attacks which are a by-product of coronary artery disease. It doesn't work quick enough to end the pain of an attack that is already occurring.

This drug is part of the group of medications known as nitrates. They work by increasing the supply of oxygen and blood to the heart by relaxing the blood vessels which reduces its overall workload. This drug helps prevent these attacks from happening when it is used regularly for a long period of time. You cannot obtain this medication on your own. It is only available via a prescription from your doctor and it is available in the following dosage forms:

  • Tablet

Conditions treated

Type of medication

  • Oral

Side effects

Along with the intended effects of this drug, it's used could produce some unwanted side effects. Not all of these may be present, but if you do experience any of the following effects, you may need to seek medical attention.

Seek advice from your healthcare professional or doctor right away if you suffer from any of the following side effects whilst taking Isosorbide Dinitrate:

Incidence not known

  • Fainting

Seek emergency help right away if you suffer from any of the following symptoms of overdose:

Symptoms of overdose

  • Change in the ability to see colors, especially yellow or blue

You may experience other side effects that are not included on the above list. It's best to check with your doctor or healthcare professional if you notice anything strange or unusual. All side effects can be reported to the FDA on 1-800-FDA-1088 if you wish.


The final dose of this drug will depend upon your individual factors and the specifics of the drug in question. Your doctor will consider your age, weight, and height, any other medications you currently taking to treat any other medical conditions. They will also consider the strength of the drug, how often you are required to take it and your reacting to the first dose. You should not alter your medication without the advice of your doctor or a healthcare professional. By changing your dose, you could alter the effectiveness of treatment or increase your risk of overdose and severe side effects. The following dose recommendations are only guidelines.

For angina prevention with oral dosage forms (sustained-release capsules or extended-release tablets ):

Adults: Initially a dose of forty milligrams twice daily. Your doctor can increase your dose as necessary. However, typically the dose is not more than 160 mg daily.

Children: The final use and dose will be determined by a doctor or healthcare professional.

For oral dosage form (tablets):

Adults: Initially, five to twenty milligrams 2 or 3 times daily. Your doctor can adjust the dose as necessary.

Children: The final use and dose will be determined by a healthcare professional or your doctor.

For sublingual dosage form (tablets):

Adults: Typically a dose of 2.5 to 5 milligrams around fifteen minutes before expected emotional or physical stress.

Children: The final use and dose will be determined by a doctor.

Missed Dose

If you miss a dose of Isosorbide Dinitrate, you should take it as soon as you've remembered. Although, if it's close to the time of your next scheduled dose, then skip the dose you have missed and returned to your regular schedule. Don't double your doses to make up for a dose you have missed.

Proper use

This type of nitrate is used to reduce the number of angina attacks over a longer period of time. It will not relieve attacks that have already begun as it works too slowly. The extended-release form of this medication works by releasing the drug gradually to provide effects for around eight to ten hours. You should consult with your doctor or healthcare professional if you also require a fast-acting drug to receive the pain of an attack.

You should take this medication first thing in the morning and maintain the same schedule daily. This medication will work best if you have a "drug-free" period of time each day when you don't take it. Your healthcare professional will schedule a "drug-free" time alongside your other doses. You should follow the schedule of dosing carefully so the medication will work as it needs to.

Sublingual tablets should not be crushed, chewed, or swallowed. They work faster when they are absorbed via the lining of the mouth. You should let the tablet dissolve by placing it under the tongue. Don't drink, eat, smoke, or use chewing tobacco whilst a tablet is dissolving.

Swallow the extended-release capsule or tablet whole. Don't crush, split or chew it.


Interactions between drugs can produce some serious side effects and reduce the effectiveness of either drug in its treatment. To help avoid these interactions occurring, it's a good idea to give your doctor or healthcare professional a full and complete list of all the medications you are currently taking. This should typically include, all over the counter medications (prescription/nonprescription drugs), all vitamin supplements and herbal products. You should also inform them of any other medical conditions you suffer from as this could increase the chance of interactions. In most cases, your doctor will avoid interactions by limiting your use of the drug, but in some cases, interactions may be necessary for your treatment plan.

The use of this medication alongside any of the following medications is not typically recommended. Your doctor may avoid treating you with this drug altogether, or they may change some of the other treatments you are taking.

  • Avanafil

Make your doctor aware if you are taking any of the medications listed below. These drugs, when taken together, could cause moderate interactions. This list is not complete.

  • Heroin

The presence of other medical conditions could affect the use of Isosorbide Dinitrate. Make sure you let your doctor or healthcare professional know if you have any other medical conditions, especially:

Congestive heart failure

Hypotension (low blood pressure)

Hypovolemia (low amount of blood): Caution should be exercised as the use of this drug could make this condition worse.

Hypertrophic cardiomyopathy (a heart disease)

Heart attack, recent


Before you commit to a medication, you should alongside your doctor weight up the associated risk along with the benefits of using this drug. Below are some of the things you will need to take into consideration.


You should let your healthcare professional or doctor know if you have ever suffered from an allergic reaction to this medication or similar drugs. It's best you also make them aware of any other allergies you may suffer from including to, dyes, preservatives, foods, and animals.

Use in pediatric population

No appropriate studies have been conducted on the relationship of age to the effects of isosorbide dinitrate in the younger population. Therefore efficacy and safety have not been established.

Use in geriatric population

Appropriate studies conducted to date have not indicated a geriatric-specific problem that could limit the usefulness of this drug in the elderly population. However, elderly patients are more likely to have age-related kidney, liver, or heart conditions, which could require an adjustment in the dose or a degree of caution to be exercised for those who are receiving isosorbide dinitrate.

Use in pregnancy and breastfeeding

Isosorbide dinitrate is under FDA pregnancy category C. This means it is unknown whether this drug could harm an unborn child. You should let your doctor know if you currently pregnant or intend on becoming pregnant whilst using this medication.

It's currently unknown whether isosorbide dinitrate can pass into breast milk or if it could harm a nursing infant. Let your doctor know if you are breastfeeding for advice.

If you are taking this medication for a long period of time, it's very important that your healthcare professional monitors your progress at regular appointments to ensure that this medication is working correctly. Your doctor may use blood or urine tests to test for unwanted side effects.

Don't take sildenafil (Viagra®), tadalafil, avanafil ( riociguat (Adempas®), Stendra®), or (Levitra®) vardenafil whilst you are using this medication. The use of these drugs in combination could cause dizziness, blurred vision, lightheadedness or even fainting. If you are taking these medications together and you experience an angina attack, you need to go to the hospital immediately.

This medication can cause headaches, however, these are a sign that the medication is working properly. Don't stop using the drug or change the time of day you use it in order to avoid the headaches. If you suffer from severe pain, then seek advice from a doctor or healthcare professional.

Lightheadedness, dizziness or faintness can occur, especially when you get up quickly from a sitting or lying position. You can arise slowly to help these symptoms.

Lightheadedness, dizziness or fainting is more likely to occur if you stand for long periods of time, drink alcohol, engage in exercise, or if the weather is warm. Whilst using this medication, you should be careful to limit the amount of alcohol you drink and take extra caution during hot weather or exercise or if you need to stand for longe periods of time.

Don't stop using this medication without first checking with your healthcare professional. They may want you to gradually reduce the dose you are using before they stop it completely.


Isosorbide Dinitrate should be stored in a closed container at room temperature and kept away from moisture, heat, and light. You should prevent this drug from freezing. Keep out of the reach of children and do not keep any medication that you no longer require or has passed its expiry date. You should seek advice from your local pharmacist for the best method of disposal for medication that you no longer need.


When used as directed, Isosorbide Dinitrate is successful in the prevention of angina attacks. This drug should only be taken as directed by your doctor and you should not change your dose without prior advice. Due to a large number of interactions that could occur with this use of this drug, it's important your doctor is aware of all medications you are taking. The safety and efficacy of this drug have not been established in the use of children. You should let your doctor know if you are currently pregnant or intend on falling pregnant whilst using this medication, or if you are currently breastfeeding. This medicine cannot relieve chest pain once it has occurred, you will need a different medication for pain relief. If you require any further information about the practical uses of this medication or you have any other questions then contact your local healthcare professional or doctor for advice.