In the U.S.—

Another commonly used name is glyceryl trinitrate.

• Antianginal

Nitrates ( NYE-trates) are used to treat the symptoms of angina (chest pain). Depending on the type of dosage form and how it is taken, nitrates are used to treat angina in three ways:

• to relieve an attack that is occurring by using the medicine when the attack begins;
• to prevent attacks from occurring by using the medicine just before an attack is expected to occur; or
• to reduce the number of attacks that occur by using the medicine regularly on a long-term basis.

When used as a lingual (in the mouth) spray, nitroglycerin is used either to relieve the pain of angina attacks or to prevent an expected angina attack.

Nitroglycerin works by relaxing blood vessels and increasing the supply of blood and oxygen to the heart while reducing its work load.

Nitroglycerin as discussed here is available only with your doctor's prescription, in the following dosage form:

Oral
• Lingual aerosol (U.S.)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For nitroglycerin lingual aerosol, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to nitrates or nitrites. Also tell your health care professional if you are allergic to any other substances, such as certain foods, preservatives, or dyes.

Pregnancy—Studies on effects in pregnancy have not been done in either humans or animals.

Breast-feeding—It is not known whether this medicine passes into breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children—Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of nitroglycerin in children with use in other age groups.

Older adults—Dizziness or lightheadedness may be more likely to occur in the elderly, who may be more sensitive to the effects of nitrates.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking nitroglycerin, it is especially important that your health care professional know if you are taking any of the following:

• Antihypertensives (high blood pressure medicine) or
• Other heart medicine or
• Sildenafil—May increase the effects of nitroglycerin on blood pressure

• Anemia (severe)

• Glaucoma—May be worsened by nitroglycerin

• Head injury (recent) or
• Stroke (recent)—Nitroglycerin may increase pressure in the brain, which can make problems worse

• Heart attack (recent)—Nitroglycerin may lower blood pressure, which can aggravate problems associated with heart attack

• Kidney disease or
• Liver disease—Effects may be increased because of slower removal of nitroglycerin from the body

• Overactive thyroid

Use nitroglycerin spray exactly as directed by your doctor. It will work only if used correctly.

This medicine usually comes with patient instructions. Read them carefully before you actually need to use it. Then, if you need the medicine quickly, you will know how to use it.

To use nitroglycerin lingual spray:

• Remove the plastic cover. Do not shake the container .
• Hold the container upright. With the container held close to your mouth, press the button to spray onto or under your tongue. Do not inhale the spray.
• Release the button and close your mouth. Avoid swallowing immediately after using the spray.

For patients using nitroglycerin oral spray to relieve the pain of an angina attack:

• When you begin to feel an attack of angina starting (chest pains or a tightness or squeezing in the chest), sit down. Then use 1 or 2 sprays as directed by your doctor. This medicine works best when you are standing or sitting. However, since you may become dizzy, lightheaded, or faint soon after using a spray, it is safer to sit rather than stand while the medicine is working. If you become dizzy or faint while sitting, take several deep breaths and bend forward with your head between your knees.
• Remain calm and you should feel better in a few minutes.
• This medicine usually gives relief in less than 5 minutes. However, if the pain is not relieved, use a second spray. If the pain continues for another 5 minutes, a third spray may be used. If you still have the chest pains after a total of 3 sprays in a 15-minute period, contact your doctor or go to a hospital emergency room immediately.

For patients using nitroglycerin oral spray to prevent an expected angina attack:

• You may prevent anginal chest pains for up to 1 hour by using a spray 5 to 10 minutes before expected emotional stress or physical exertion that in the past seemed to bring on an attack.

Dosing—

The dose of nitroglycerin lingual spray will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of nitroglycerin lingual spray. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (lingual spray):
  • For chest pain:
    • Adults—One or two sprays on or under the tongue. The dose may be repeated every five minutes as needed. If the chest pain is not relieved after a total of three sprays in a fifteen-minute period, call your doctor or go to the emergency room right away.

Storage—

To store this medicine

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep the medicine from freezing.
• Do not puncture, break, or burn the aerosol container, even after it is empty.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Do not take sildenafil (e.g., Viagra) if you are taking this medicine. When sildenafil is taken with nitrates, the combination can lower blood pressure and cause dizziness, lightheadedness, or fainting. In some case, sildenafil taken with nitrates has caused death.

If you have been using this medicine regularly for several weeks, do not suddenly stop using it. Stopping suddenly may bring on attacks of angina. Check with your doctor for the best way to reduce gradually the amount you are using before stopping completely.

Dizziness, lightheadedness, or faintness may occur , especially when you get up quickly from a lying or sitting position. Getting up slowly may help. If you feel dizzy, sit or lie down.

The dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. While you are taking this medicine, be careful to limit the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.

After using a dose of this medicine you may get a headache that lasts for a short time. This is a common side effect, which should become less noticeable after you have used the medicine for a while. If this effect continues or if the headaches are severe, check with your doctor.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Rare
  • Blurred vision;  dryness of mouth;  headache (severe or prolonged);  skin rash 
  
  

• Signs and symptoms of overdose (in the order in which they may occur)
  • Bluish-colored lips, fingernails, or palms of hands;  dizziness (extreme) or fainting;  feeling of extreme pressure in head;  shortness of breath ;  unusual tiredness or weakness;  weak and fast heartbeat;  fever;  convulsions (seizures) 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Dizziness or lightheadedness, especially when getting up from a lying or sitting position;  fast pulse;  flushing of face and neck;  headache ;  nausea or vomiting;  restlessness  
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.