Nitroglycerin for Heart Disease

What Members SayTop TipsSide EffectsFAQs

Nitroglycerin is a prescription medication approved by the U.S. Food and Drug Administration (FDA) to relieve or prevent chest pain caused by coronary artery disease and to treat certain heart-related conditions in a hospital.

What Members Say

MHT logo These insights are based on 121 comments about nitroglycerin from MyHeartDiseaseTeam members. These are the experiences of a small number of people and are not meant to be medical advice.

Benefits:

Chest pain often eases quickly after a sublingual tablet or hospital nitroglycerin treatment.
Taking nitroglycerin before activity can help prevent angina for some daily routines.
Long-acting forms can reduce how often angina happens after an adjustment period.

Considerations:

Headaches are common, especially when starting treatment or after taking a dose.
Dizziness, lightheadedness, and blood pressure drops can happen, especially when standing up.
Chest pain does not always improve, and ongoing pain needs prompt medical attention.

How Nitroglycerin Works and How It’s Taken

Nitroglycerin is a nitrate medicine that releases nitric oxide. This relaxes and widens blood vessels, lowers the heart’s workload, and reduces the amount of oxygen the heart needs.

Doctors prescribe nitroglycerin to relieve or prevent chest pain caused by coronary artery disease. Some forms are also used in a hospital for certain heart-related conditions.

Typical Dosing for Heart Conditions

Dosing of nitroglycerin depends on the form of the medication.

Sublingual Tablet

Place one tablet under the tongue or in the cheek pouch at the first sign of chest pain. Let it dissolve without swallowing. Do not chew, crush, or swallow. Repeat every five minutes as needed, up to three tablets in 15 minutes. It may also be taken five to 10 minutes before an activity that may trigger chest pain. Seek prompt medical attention if pain continues after three tablets or feels different from usual.

Lingual Spray

Spray one or two doses onto or under the tongue when chest pain begins. Repeat about every five minutes as needed, up to three sprays in 15 minutes. It may also be used five to 10 minutes before an activity that may trigger chest pain. Do not inhale the spray. Seek prompt medical attention if pain continues after three sprays.

Skin Patch

The patch is used to prevent chest pain. The suggested starting dose is 0.2 milligrams per hour to 0.4 milligrams per hour. Wear it for 12 to 14 hours, then remove it for 10 to 12 hours each day. It does not treat chest pain that has already started.

Topical Skin Ointment

The ointment is used to prevent chest pain. A common starting dose is 0.5 inches, or 7.5 milligrams, applied in the morning and again six hours later. Leave a 10- to 12-hour medicine-free period each day. It does not treat an active chest pain attack.

Intravenous Nitroglycerin

Intravenous (IV) nitroglycerin is given through a vein by a healthcare professional using an infusion pump. It may be used in a hospital for high blood pressure around surgery, heart failure during a heart attack, severe angina not relieved by other medicines, or controlled low blood pressure during surgery. The dose is adjusted based on blood pressure, heart rate, and response. Concentrated injection must be diluted and must not be injected directly into a vein.

This information is based on prescribing information, but your healthcare provider may tailor your treatment plan. Always follow their guidance.

Top Advice From Members on Nitroglycerin

MHT logo These insights are based on 121 comments about nitroglycerin from MyHeartDiseaseTeam members.

Members who use nitroglycerin often talk about keeping it close by, paying attention to how well it works, and telling their cardiologist when symptoms change. They also frequently mention side effects like headaches and lightheadedness, as well as the need to ask about longer-acting options when chest pain keeps coming back.

1

Keep nitroglycerin with you for sudden symptoms.
“I do have nitroglycerin sublingual tablets in my pocket at all times per my doctor for the last five years.”
2

Notice whether it relieves symptoms, and speak up if it does not.
“Nitroglycerin didn’t help recently in my chest pain, so last Sunday the doctor told me we have to look at GI problems.”
3

Tell your doctor if you need it more often.
“I’m having to take two to four nitroglycerin each time I’m having this chest pain, which is almost every single day. I need to let my doctor know.”

Connect with others who understand life with heart disease. Join MyHeartDiseaseTeam for free.

Nitroglycerin Side Effects

In clinical studies of nitroglycerin the most common side effects differ based on the dosage form. These include:

Sublingual tablet:

Headache
Dizziness
Weakness
Flushing
Lightheadedness

Lingual spray:

Headache
Dizziness
Tingling or unusual skin sensations

Skin patch or ointment:

Headache
Lightheadedness
Dizziness
Low blood pressure
Skin irritation

IV form:

Headache
Lightheadedness
Low blood pressure
Fainting

Serious Side Effects and Warnings

Nitroglycerin can cause serious side effects that may require immediate medical attention. These include:

Severe low blood pressure — Hypotension can cause nausea, vomiting, weakness, pale skin, sweating, worsening chest pain, or fainting.
Syncope (fainting) — Passing out has been reported due to nitrate-related blood vessel widening.
Worsening angina in hypertrophic obstructive cardiomyopathy — Nitroglycerin may make chest pain worse for people with this heart muscle condition.
Severe allergic reaction — Hypersensitivity reactions can include rash and other allergic symptoms.
Methemoglobinemia — This rare condition reduces the blood’s ability to carry oxygen.

Get medical help right away if you think you are having a serious reaction.

What To Know Before Taking Nitroglycerin

Tell your doctor if you are allergic to nitroglycerin, other nitrates or nitrites, or any ingredient in your product. If you use a patch, also tell your doctor if you are allergic to adhesives.

Before using nitroglycerin, tell your doctor if you:

Have low blood pressure, are dehydrated, or often feel faint
Have severe anemia
Have increased pressure inside your skull, such as from a brain bleed or head injury
Have circulatory failure or shock
Have hypertrophic cardiomyopathy or another serious heart condition
Are pregnant, plan to become pregnant, or are breastfeeding
Are age 65 or older, because you may be more likely to develop low blood pressure, dizziness, or falls

Tell your doctor about all medicines you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements.

Do not use nitroglycerin with:

PDE-5 inhibitors, such as avanafil, sildenafil, tadalafil, or vardenafil
Soluble guanylate cyclase stimulator, such as riociguat

These combinations can cause dangerously low blood pressure, fainting, or reduced blood flow to the heart.

Tell your doctor about all medicines and supplements you take, especially:

Blood pressure medicines, beta-blockers, calcium channel blockers, other nitrates, or other medicines that widen blood vessels
Ergotamine or related migraine medicines
Heparin or tissue-type plasminogen activator, also called t-PA, if you are receiving hospital treatment

Alcohol can increase dizziness and low blood pressure. Ask your doctor whether you should avoid it.

For sublingual tablets, a small sip of water before the dose may help the tablet dissolve if your mouth is dry.

IV nitroglycerin has additional precautions. Tell the healthcare team if you have diabetes or heart, kidney, or liver problems. Certain IV products contain dextrose, and the amount of fluid given may need close monitoring.

Do not place a defibrillator paddle over a nitroglycerin patch. Used patches still contain medicine and should be kept away from children and pets.

If you are pregnant, planning to become pregnant, or breastfeeding while taking nitroglycerin, talk with your doctor about the risks and benefits.

Community FAQs

These answers are fact-checked by our editorial staff.

How effective is nitroglycerin for heart conditions?

Nitroglycerin can work quickly to relieve angina caused by coronary artery disease. Sublingual tablets usually begin working within one to three minutes, reach their strongest effect by about five minutes, and continue working for at least 25 minutes. They may also be taken five to 10 minutes before an activity that may trigger chest pain.

Other forms are used to help prevent angina or treat certain heart-related conditions in a hospital. Skin patches and topical ointment can reduce exercise-related angina when used on an intermittent schedule that includes a daily medicine-free period. IV nitroglycerin can lower blood pressure and reduce pressure on the heart, but the dose must be adjusted based on the person’s response.

Effectiveness depends on the dosage form, the condition being treated, and whether the medicine is used as directed. Continuous use can lead to tolerance, meaning it may become less effective over time.

How long does nitroglycerin take to work for heart disease?

How quickly nitroglycerin works depends on the dosage form. A sublingual tablet usually starts working within one to three minutes, reaches its strongest effect by about five minutes, and lasts for at least 25 minutes. Lingual spray is also used for rapid relief of angina, but the study does not give the same exact onset and duration times. Skin patches and topical ointment work more slowly and are used to prevent angina, not to stop an attack that has already started. IV nitroglycerin is given in a hospital, where the dose is adjusted based on blood pressure, heart rate, and response.

How often is nitroglycerin taken for heart disease?

How often nitroglycerin is used depends on the dosage form:

Sublingual tablet — Take one tablet at the first sign of chest pain and then repeat every five minutes as needed, up to three tablets in 15 minutes. It may also be taken five to 10 minutes before an activity that may trigger angina.
Lingual spray — Use one or two sprays when chest pain begins and then repeat about every five minutes as needed, up to three sprays in 15 minutes. It may also be used five to 10 minutes before a triggering activity.
Skin patch — The patch is usually worn for 12 to 14 hours, followed by 10 to 12 hours without a patch each day.
Topical ointment — A common starting schedule is 0.5 inches in the morning and again six hours later, followed by a 10- to 12-hour medicine-free period.
IV form — This form is given continuously in a hospital, with the dose adjusted based on the person’s response.

Always follow your doctor’s instructions for the specific dosage form prescribed.