Nitroglycerin: Uses, How It Works, Medicines
Nitroglycerin, also called glyceryl trinitrate (GTN), is a prescription nitrate used for angina, which is chest pain from the heart not getting enough blood. Under-the-tongue forms relieve an attack, while sustained-release capsules and patches are used to prevent attacks. It must not be taken with erectile dysfunction medicines such as sildenafil.
Also known as: Glyceryl trinitrate, GTN, Nitroglycerin SR, Nitroglycerin 2.6 mg, Angispan
Pharmacist review in progress. This page is based on the sources listed below and is being checked by our registered pharmacist.
How does Nitroglycerin work?
Nitroglycerin releases nitric oxide in the body, which relaxes blood vessels. Less blood returns to the heart and the heart works less hard, so it needs less oxygen and angina eases.
How to take Nitroglycerin
Follow the label or your doctor's advice. How it is taken depends on the form, such as an under-the-tongue tablet, spray, patch or sustained-release capsule. Your doctor decides the dose.
Side effects of Nitroglycerin
Most people take it without serious problems. Some side effects are common and mild, but a few need medical help.
Uncommon or mild
- Headache, which often fades after a few days of regular use
- Dizziness, weakness or tiredness
- Flushing of the face
- Nausea
Rare but serious: get medical help
- Fainting or loss of consciousness
- A heartbeat that is much faster or slower than usual
- Chest pain that is different from, or worse than, your usual angina
- New or worsening breathing difficulty, or blue or grey lips or skin
- Swelling of the face, lips, tongue or throat (a severe allergic reaction). Get medical help immediately
Who should be careful
Some people need to check with a doctor before taking nitroglycerin, or need extra care while taking it.
When the label says not to use it
- Allergy to nitroglycerin or any ingredient
- Taking sildenafil, tadalafil, vardenafil or riociguat
- Severe anaemia, raised pressure inside the head or shock, as set out in the label
- Erectile dysfunction medicines (sildenafil, tadalafil, vardenafil) and riociguat: never take together with this medicine
- Low blood pressure
- Recent head injury, bleeding in the brain or raised pressure inside the head
- Recent stroke, recent heart attack or heart problems other than angina
- Anaemia or glaucoma
- Hypertrophic cardiomyopathy (a thickened heart muscle): nitrates can make the chest pain worse
- Pregnancy and breastfeeding: human data are limited; ask your doctor
- Surgery or dental work: tell the doctor or dentist that you take it
Medicines and things that interact with Nitroglycerin
Nitroglycerin can change how other medicines work, and some medicines change its effect. Tell your doctor or pharmacist about everything you take, including herbal products and medicines bought over the counter.
- Erectile dysfunction medicines such as sildenafil, tadalafil and vardenafil, and riociguat: the combination can cause a dangerous fall in blood pressure and must not be used
- Alcohol: lowers blood pressure and can add to dizziness
- Other blood pressure medicines and medicines that widen blood vessels: blood pressure may fall too low
If someone takes too much
Taking too much can cause headache, a fast heartbeat, dizziness and fainting. Call 112 or go to the nearest hospital if lips, tongue or skin turn blue or grey, and take the medicine pack with you. Do not drive yourself.
Regulatory status in India
Approved for sale in India as a prescription medicine. Nitroglycerin is not on the CDSCO list of medicines banned under section 26A of the Drugs and Cosmetics Act as a single ingredient. Fixed-dose combinations that contain it with other medicines may be treated differently, so check the ingredient list on the pack.
Type of medicine
Nitroglycerin belongs to this type of medicine.
Medicines that contain Nitroglycerin
These medicines sold in India contain Nitroglycerin. They are listed A to Z, not ranked.
- Angispan-TR 2.6 · 2.6 mg sustained-release capsule
What is Nitroglycerin used for?
Medicines that contain Nitroglycerin are used for these conditions.
Other medicines of the same type
These active ingredients are of the same type as Nitroglycerin.
Common questions
What is nitroglycerin (GTN) used for?
It is a prescription medicine used for angina. Under-the-tongue forms relieve an attack, and long-acting forms such as sustained-release capsules and patches help prevent attacks. Which form you need is a doctor's decision.
Can nitroglycerin be taken with sildenafil?
No. Erectile dysfunction medicines such as sildenafil, tadalafil and vardenafil can cause a dangerous fall in blood pressure when combined with nitroglycerin. The labels forbid the combination. Tell every doctor and pharmacist.
Is the sustained-release capsule the same as the under-the-tongue tablet?
No. The under-the-tongue tablet or spray acts within minutes to relieve an attack. A sustained-release capsule releases the medicine slowly and is meant to help prevent attacks. They are not interchangeable without a doctor's advice.
Why does nitroglycerin cause headache?
It widens blood vessels, including those in the head. The NHS says headaches usually fade after a few days of regular use, and paracetamol is considered safe for them. See a doctor if the headache is severe or lasts over a week.
What if chest pain does not go away?
Chest pain that does not settle with rest or the medicine your doctor prescribed for attacks could be a heart attack. Call 112 or go to hospital at once and do not drive yourself.
Sources
- Nitroglycerin sublingual tablets: prescribing information. DailyMed, US National Library of Medicine
- Side effects of glyceryl trinitrate (GTN). NHS (UK)
- Who can and cannot take glyceryl trinitrate (GTN). NHS (UK)
- How and when to take glyceryl trinitrate (GTN). NHS (UK)
- ATC/DDD Index: C01DA Organic nitrates. WHO Collaborating Centre for Drug Statistics Methodology
- List of drugs prohibited for manufacture and sale through gazette notifications under section 26A of the Drugs & Cosmetics Act 1940. Central Drugs Standard Control Organisation (CDSCO)