Nitrate (Oral route)

Brand Names:

  • Dilatrate-SR
  • Imdur
  • Imdur ER
  • Ismo
  • Isochron
  • Isordil Titradose
  • Monoket
  • Nitrocot
  • Nitro-Time

Dosage Forms:

  • Tablet
  • Tablet, Extended Release
  • Capsule, Extended Release
  • Tablet, Chewable

Uses of This Medicine:

Nitrates 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 taken orally and swallowed, nitrates are used to reduce the number of angina attacks that occur. They do not act fast enough to relieve the pain of an angina attack.

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

Nitrates may also be used for other conditions as determined by your doctor.

These medicines are available only with your doctor's prescription.

Before Using This Medicine:


Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Studies on these medicines have been done only in adult patients, and there is no specific information comparing use of nitrates 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.


Nitrates have not been studied in pregnant women. However, studies in rabbits given large doses of isosorbide dinitrate have shown adverse effects on the fetus. Before taking these medicines, make sure your doctor knows if you are pregnant or if you may become pregnant.


It is not known whether these medicines pass 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 these medicines and who wish to breast-feed should discuss this with their doctor.

Other medicines

Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.

  • Sildenafil
  • Tadalafil
  • Vardenafil

Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

  • Alteplase, Recombinant

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Other medical problems

The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:

  • Anemia (severe)
  • Glaucoma May be worsened by nitrates
  • Head injury (recent) or
  • Stroke (recent) Nitrates may increase pressure in the brain, which can make problems worse.
  • Heart attack (recent) Nitrates 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

Proper Use of This Medicine:

Take this medicine exactly as directed by your doctor. It will work only if taken correctly.

This form of nitrate is used to reduce the number of angina attacks. In most cases, it will not relieve an attack that has already started because it works too slowly (the extended-release form releases medicine gradually over a 6-hour period to provide its effect for 8 to 10 hours). Check with your doctor if you need a fast-acting medicine to relieve the pain of an angina attack.

Take this medicine with a full glass (8 ounces) of water on an empty stomach. If taken either 1 hour before or 2 hours after meals, it will start working sooner.

Extended-release capsules and tablets are not to be broken, crushed, or chewed before they are swallowed. If broken up, they will not release the medicine properly.


The dose medicines in this class 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 these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For angina (chest pain):
    • For regular (short-acting) oral dosage forms (capsules or tablets):
      • Adults 5 to 40 mg four times a day.
      • Children Dose must be determined by your doctor.
    • For long-acting oral dosage forms (extended-release capsules or tablets):
      • Adults 20 to 80 mg every eight to twelve hours.
      • Children Dose must be determined by your doctor.
  • For angina (chest pain):
    • For regular (short-acting) oral dosage form (tablets):
      • Adults 20 mg two times a day. The two doses should be taken seven hours apart.
      • Children Use and dose must be determined by your doctor.
    • For long-acting oral dosage form (extended-release tablets):
      • Adults 30 to 240 mg once a day.
      • Children Use and dose must be determined by your doctor.
  • For angina (chest pain):
    • For long-acting oral dosage forms (capsules or tablets):
      • Adults 2.5 to 9 mg every eight to twelve hours.
      • Children Dose must be determined by your doctor.

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.


Keep out of the reach of children.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using This Medicine:

Do not take sildenafil (e.g., Viagra), tadalafil (e.g., Cialis), or vardenafil (e.g., Levitra) if you are taking this medicine. When sildenafil, tadalafil, or vardenafil are taken with nitrates, the combination can lower blood pressure and cause dizziness, lightheadedness, or fainting. In some cases, sildenafil, tadalafil, or vardenafil taken with nitrates has caused death. If you are taking sildenafil, tadalafil, or vardenafil and you experience an angina attack, you must go to the hospital right away.

If you have been taking this medicine regularly for several weeks or more, 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 taking 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 taking 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 taken the medicine for a while. If this effect continues, or if the headaches are severe, check with your doctor.

For patients taking the extended-release dosage forms of isosorbide dinitrate:

  • Partially dissolved tablets have been found in the stools of a few patients taking the extended-release tablets. Be alert to this possibility, especially if you have frequent bowel movements, diarrhea, or digestive problems. Notify your doctor if any such tablets are discovered. The tablets must be properly digested to provide the correct dose of medicine.

Side Effects of This Medicine:

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:

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
convulsions (seizures)

Some 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. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

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

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

Last Updated: 6/12/2013
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