This medication is used to relieve chest pain (angina) in people that have a certain heart condition (coronary artery disease). It may also be used before physical activities (such as exercise, sexual activity) to help prevent chest pain.

Nitroglycerin belongs to a class of drugs known as nitrates. Angina occurs when the heart muscle is not getting enough blood. This drug works by relaxing and widening blood vessels so blood can flow more easily to the heart.

Ask your doctor now for exact instructions on how to use your nitroglycerin and when to call for emergency medical help (911).

Read the Patient Information Leaflet if available from your pharmacist before you start using nitroglycerin and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Sit down before using this medication. Place 1 tablet under the tongue and allow it to dissolve as directed by your doctor. Do not chew or swallow the tablet. The dosage is based on your medical condition and response to treatment.

If you are using this medication to relieve chest pain once it occurs, use it as soon as possible. If your chest pain has not improved or if it has worsened 5 minutes after you use this drug, call emergency medical help (911). After calling the emergency number, use another dose. Five minutes after the second dose, if you still have chest pain and the ambulance has not arrived, use a third dose. If your chest pain is not gone after 15 minutes and 3 doses of nitroglycerin, call emergency medical help (911) if you have not called already. Do not use more than 3 doses during an attack unless directed by your doctor.

If you are using this medication to prevent chest pain before physical activities, use it 5 to 10 minutes before the activity.

Headache, dizziness, lightheadedness, nausea, flushing, and burning/tingling under the tongue may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Headache is often a sign that this medication is working. Your doctor may recommend treating headaches with an over-the-counter pain reliever (such as acetaminophen, aspirin). If the headaches continue or become severe, tell your doctor promptly.

To reduce the risk of dizziness and lightheadedness, get up slowly when rising from a sitting or lying position.

Remember that this medication has been prescribed because your doctor 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
• fast/irregular/pounding heartbeat

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
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using this medication, tell your doctor or pharmacist if you are allergic to it; or to similar drugs (such as isosorbide mononitrate); or to nitrites; 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.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• recent head injury
• anemia
• low blood pressure
• dehydration
• other heart problems (such as recent heart attack)

This drug may make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Older adults may be more sensitive to the side effects of this medication, especially dizziness and lightheadedness which could increase the risk of falls.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk or if it may harm a nursing infant. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• drugs used to treat erectile dysfunction-ED or pulmonary hypertension (such as sildenafil, tadalafil)
• certain drugs to treat migraine headaches (ergot alkaloids such as ergotamine)
• riociguat
• vericiguat

This medication may interfere with certain lab tests (such as blood cholesterol levels), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: slow heartbeat, vision changes, severe nausea/vomiting, sweating, cold/clammy skin, bluish fingers/toes/lips.

Do not share this medication with others.

Not applicable.

Store in the original glass bottle at room temperature away from light, heat, and moisture. Do not store in the bathroom. Tightly close the bottle when not in use. 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 or local waste disposal company.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).