Do NOT use Nitroglycerin if:

• you are allergic to any ingredient in Nitroglycerin
• you suspect your are having a heart attack
• you have increased pressure inside the head
• you have severe anemia
• you are currently taking a phosphodiesterase type 5 inhibitor (eg, sildenafil), a medicine used frequently for sexual dysfunction.

Contact your doctor or health care provider right away if any of these apply to you.

Some medical conditions may interact with Nitroglycerin. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding
• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
• if you have allergies to medicines, foods, or other substances
• if you drink alcoholic beverages
• if you have a history of heart failure, overactive thyroid, recent head trauma, recent heart attack, recent stroke, head injury, or low blood pressure.

Some medicines may interact with Nitroglycerin. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Beta-blockers (eg, propranolol), calcium channel blockers (eg, diltiazem), phenothiazines (eg, thioridazine), or phosphodiesterase type 5 inhibitors (eg, sildenafil) because side effects such as severely low blood pressure may occur
• Alteplase or heparin because the effectiveness of these medicines may be decreased
• Salicylates (eg, aspirin) because the effectiveness of nitroglycerin may be altered. Control of blood pressure may be impaired and your doctor may need to adjust your dose.

This may not be a complete list of all interactions that may occur. Ask your health care provider if Nitroglycerin may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

Important safety information:

• Nitroglycerin may cause dizziness or blurred vision. Use caution while driving or performing other tasks requiring alertness, coordination, or physical dexterity.
• Nitroglycerin may cause dizziness, lightheadedness, or fainting. Alcohol, hot weather, exercise, and fever can increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Also, sit or lie down at the first sign of dizziness, lightheadedness, or weakness.
• To avoid tooth and gum decay, vary location sites and brush your teeth after the tablet has completely dissolved.
• Do not fall asleep with a tablet in your mouth.
• Lab tests, including blood electrolytes and blood pressure, may be performed to monitor your progress or to check for side effects. Be sure to keep all doctor and lab appointments.
• Nitroglycerin is not recommended for use in children. Safety and effectiveness have not been confirmed.
• Pregnancy and breast-feeding: If you become pregnant, discuss with your doctor the benefits and risks of using Nitroglycerin during pregnancy. It is unknown if Nitroglycerin is excreted in breast milk. If you are or will be breast-feeding while you are using Nitroglycerin, check with your doctor or pharmacist to discuss the risks to your baby.

All medicines may cause side effects, but many people have no, or minor, side effects.

Check with your doctor if any of these most common side effects persist or become bothersome:

Burning or tingling in the mouth; dizziness; flushing; headache; heavy sweating; lightheadedness; nausea; pale skin; vomiting.

Seek medical attention right away if any of these severe side effects occur:

Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); blurred vision; fainting; increased chest pain; pounding in the chest; slow heartbeat.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider.