Nitroglycerin (Intravenous)

Nitroglycerin is used to relax the blood vessels and subsequently reduce blood pressure in those who have recently had a heart attack.

Overview

Nitroglycerin is used intravenously to treat high blood pressure or control congestive heart failure in patients who have had a recent heart attack. It may also be used during surgery to induce low blood pressure, or to treat angina (chest pain) in patients who have not been successfully treated with other medicines. By injecting it directly into a vein, the drug works much faster than if it was administered by other methods.

Nitroglycerin is a nitrate, and it works to relax the blood vessels in order that blood can flow more easily throughout the body. This means that the heart does not have to work so hard when pumping blood, which is essential for patients who are being treated for heart attack.

Intravenous nitroglycerin can only be administered by a doctor or other healthcare professional in a hospital or clinical environment. Patients will not be expected to administer IVs themselves at home. In the US, the drug is also known as Nitro-Bid and NITRONAL.

Conditions Treated?

  • High blood pressure
  • Congestive heart failure
  • Heart attack
  • Angina

Type Of Medicine?

  • Nitrate

Side Effects

Sometimes nitroglycerin can cause unwanted effects as well as its needed effects. While it is unlikely that all side effects will occur, patients should be prepared for them in order that they can recognize when it is necessary to report them to a healthcare professional. If patients are unsure as to the severity of a side effect, they should speak to their doctor.

The following side effects should be reported to a doctor or nurse immediately:

  • Rare

O Blue lips, fingernails or palms

O Pale skin

O Unusual bleeding or bruising

O Dark urine

O Headache

O Fever

O Sore throat

O Difficulty breathing

O Rapid heart rate

O Dizziness or lightheadedness

O Unusual tiredness or weakness

  • Incidence unknown

O Arm, back, or jaw pain

O Chest pain or discomfort

O Chest tightness or heaviness

O Fast or irregular heartbeat

O Dizziness, faintness or lightheadedness when arising

O Fainting

O Blurred vision

O Confusion

O Sweating

If you experience any other unwanted effects not listed here, ask your doctor about them. You could also report side effects to the FDA, or your doctor may do this on your behalf.

If any of the following signs of overdose occur, tell your doctor or nurse immediately:

  • Blurred vision or loss of vision
  • Change in ability to see colors, particularly yellow or blue
  • Disturbed color perception
  • Double vision
  • Tunnel vision
  • Halos around lights
  • Overbright appearance of lights
  • Night blindness
  • Bulging spot on the head (in infants)
  • Change in consciousness
  • Loss of consciousness
  • Convulsions
  • Paralysis
  • Cold, clammy skin
  • Flushed skin
  • Increased sweating
  • Feeling of constant movement of surroundings or self
  • Sensation of spinning
  • Severe, throbbing headache
  • Loss of appetite
  • Nausea or vomiting
  • Slow or irregular heartbeat

Dosage

Your doctor will determine an appropriate dose of nitroglycerin based on a number of factors, including the condition being treated and your medical history. For example, they may administer lower doses if you have liver or kidney problems. You may only require one injection of the drug, or multiple injections, depending on the severity of your condition and how successfully the drug works. Your dose may be gradually increased over a period of time if necessary.

Intravenous nitroglycerin is injected directly into the vein and will be administered by a doctor, nurse, or other healthcare professional. If you have any questions about the IV, consult your doctor.

Interactions

It is very important that your doctor is aware of all the medicines you take before they administer nitroglycerin. You should mention both prescribed and over-the-counter medicines, as well as any herbal supplements or vitamins you take. It may be helpful to keep a list of medicines with you which you can show to any doctor or healthcare professional who treats you.

The medicines listed below are those which pose the highest risk of harmful interaction, but this may not be an exhaustive list of all interactions, so be sure to mention all the medicines you take when discussing treatment with your doctor.

The use of the following medicines at the same time as nitroglycerin is not recommended. If you do take them, your doctor may decide not to treat you with nitroglycerin, or they may change some of the medicines you currently take.

  • Avanafil (Stendra)
  • Riociguat (Adempas)
  • Sildenafil (Revatio, Viagra)
  • Tadalafil (Adcirca, Cialis)
  • Vardenafil (Levitra, Staxyn)

The following medicines are not recommended for use at the same time as nitroglycerin, but they may still be administered if both medicines are deemed important. Your doctor may change the dose or the way you take your existing medicines to minimize the risk of interactions.

  • Alteplase, recombinant (Activase, Cathflo Activase)
  • Heparin (Heparin Sodium ADD-Vantage)

The following medicines can cause an increased risk of certain side effects when used at the same time as nitroglycerin. If both medicines are deemed important and necessary, your doctor may adjust your dosages or change the way you take existing medicines to minimize the risk of side effects.

  • Acetylcysteine (Mucomyst-10)
  • Aspirin (Arthritis Pain, Ascriptin, Aspir 81, Aspir-Low, Bayer Childrens Aspirin, Bufferin Low Dose, Durlaza, Ecotrin, Ecpirin, Fasprin, Halfprin, Miniprin)
  • Dihydroergotamine (Migranal)
  • Pancuronium

Warnings

Contraindicated conditions

Make sure your doctor knows about your full medical history before they administer nitroglycerin.

Patients with the following heart conditions should not be given nitroglycerin:

People with allergy to corn or corn products should also not be given the drug.

The following conditions may be worsened by the use of nitroglycerin. The drug may still be administered if it is deemed important and more beneficial than potential risks, but doctors may monitor patients more closely.

  • Hypertrophic cardiomyopathy
  • Hypotension (low blood pressure)
  • Hypovolemia (low blood volume)
  • Diabetes

Patients with severe kidney or liver disease may not be able to take nitroglycerin. This is because the drug may be removed from the body at a much slower rate than in people without kidney or liver problems. Subsequently, the drug may have more powerful effects and severe side effects may be more likely. Depending on the severity of your condition, doctors may continue to prescribe nitroglycerin but at lower dosages.

Pediatric use

There have not been adequate studies to determine the safety and efficacy of intravenous nitroglycerin in children. Use of the drug in the pediatric population is therefore cautious.

Geriatric use

Nitroglycerin appears to be just as effective when treating elderly patients as it is in treating younger adults. However, elderly patients are more likely to have age-related kidney or liver problems, and doctors may therefore be more cautious in prescribing it. Lower doses may therefore be initially administered to older patients.

Pregnancy and breastfeeding

Animal studies have demonstrated that nitroglycerin can be harmful to the fetus, but there have not been adequate controlled studies in human pregnancies. The drug is therefore FDA pregnancy category C, which means it should only be used if the potential benefits of the drug outweigh potential risks to the fetus. If there is a chance you could be pregnant, let your doctor know before you are administered nitroglycerin.

It is not known if nitroglycerin is excreted in human breast milk and, if it is, what effect it may have on nursing infants. Breastfeeding is therefore not recommended while taking this drug.

Allergies

Tell your doctor if you have had an allergic reaction to nitroglycerin in the past, or to drugs like it. You should also mention any other allergies you suffer from, including food, animal, pollen, drug, chemical, and dye allergies so that your doctor can check that you are not allergic to any of the ingredients in nitroglycerin. It is particularly important to tell your doctor if you are allergic to corn or corn products, as you will not be able to take nitroglycerin.

Storage

Intravenous nitroglycerin is only ever administered in a hospital environment and by a doctor, nurse, or other healthcare professional. Patients will therefore not be required to store this medicine at home.

Summary

Intravenous nitroglycerin is used to relax the blood vessels and reduce blood pressure in patients with congestive heart failure or who have had a heart attack. It can also be used to treat acute angina when other drugs have not successfully treated the problem. Sometimes it is used to induce low blood pressure during surgery.

Patients will only receive nitroglycerin IV in a hospital environment. They will not have to administer the drug themselves. A doctor will supervise the treatment closely to check how well it is working and to look out for harmful side effects. Patients should tell their doctor right away if they develop a severe headache, blue lips or fingernails, dizziness or faintness, new or worsened chest pain, new or worsened breathing problems, and vision problems or changes to vision.

This drug should not be administered to people with corn allergy, constructive pericarditis, restrictive cardiomyopathy, or pericardial tamponade.