Nitroglycerin

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Jan 13, 2023

Warnings


Nitroglycerin Risks, Warnings, and Complications


Nitroglycerin can cause or worsen health problems in some people. Talk to your doctor or pharmacist about other treatment options and lifestyle changes if you are at increased risk of complications from nitroglycerin use.

  • NOT FOR USE DURING A HEART ATTACK: Nitroglycerin is not for use during a heart attack. If you think you may be having a heart attack, call 911 or go to the nearest emergency room. 

  • USE IN PATIENTS WITH CERTAIN HEART CONDITIONS: Nitroglycerin may not be right for you if you have congestive heart failure. Your doctor will decide whether it is safe for you to take nitroglycerin. 

     If you have a condition called hypertrophic cardiomyopathy, nitroglycerin could make your chest pain worse. The risk of this occurring is higher if you are over 65 years old. Tell your doctor immediately if you develop worsening chest pain after taking nitroglycerin.

  • LOW BLOOD PRESSURE: Some people can develop dangerously low blood pressure after taking nitroglycerin. This is more likely to occur when you first start taking the medicine and change positions from lying to sitting or standing. Older adults (age 65+), people who have low blood pressure already, and those who are dehydrated are at higher risk. Be sure to change positions slowly until your body gets used to nitroglycerin. Seek emergency medical help if you feel faint or experience an irregular heartbeat, weakness, nausea, vomiting, vision changes, or cold and clammy skin.

  • TOLERANCE: Taking nitroglycerin for a long time can make your body tolerant to the medicine. Meaning, the medicine will not work as well as it used to and you will not get relief of chest pain from the same amount of medicine as before. If this happens, do not take a higher dose of nitroglycerin without your doctor’s approval. Taking high doses of nitroglycerin and stopping suddenly can put you at risk of withdrawal symptoms, including chest pain, heart attack, and even death. If you develop tolerance, your doctor may tell you to “take a break” and stay off nitroglycerin and other nitrates for some time.


Precautions Before Starting Nitroglycerin

Tell your healthcare provider if you have ever had an allergic reaction to nitroglycerin patches, tablets, capsules, sprays, ointment, or other dosage forms. Also tell your doctor if you have had allergic reactions to any other medications. Your pharmacy can give you a complete list of active and inactive ingredients in nitroglycerin formulations.

Give your doctor and pharmacist a complete list of your medications, including prescription drugs, over-the-counter medications, vitamins, and herbal supplements. This can help avoid dangerous interactions between your medications.

Give your doctor a complete medical history. Nitroglycerin may not be right for people with certain medical conditions, such as anemia, dehydration, recent heart attack, heart failure, hypertrophic cardiomyopathy, low blood pressure, or increased pressure in the skull.

Tell your doctor if you are pregnant, could be pregnant, or are planning a pregnancy, or if you are feeding breast milk to an infant.

Precautions During Use of Nitroglycerin

Keep all your appointments with your doctors and laboratory personnel. This medication will treat your symptoms but it will not cure your condition. Continue taking nitroglycerin as directed by your doctor even if you feel well. Do not stop taking nitroglycerin without your doctor’s approval.

If you take certain other drugs which cause dry mouth, nitroglycerin sublingual tablets may not dissolve properly. Drugs that can cause this problem include antihistamines, certain antidepressants, and medicines given to people with irritable bowel syndrome, stomach ulcers, urinary problems, and Parkinson’s disease. If this occurs, talk to your doctor about using artificial saliva or chewing gum to help the nitroglycerin sublingual tablet dissolve.

Nitroglycerin can cause dizziness and lightheadedness, especially when changing positions. Arise slowly from lying or sitting positions to standing. Put your feet on the ground for a few minutes before standing to prevent falls and injuries.

Avoid alcoholic drinks while on nitroglycerin. Alcohol can make the side effects of nitroglycerin worse. 

You may experience headaches while on nitroglycerin. This is a sign that the medicine is working. Do not change the time when you take your medicine to avoid the headaches. This may cause the medicine to stop working properly. Talk to your doctor for alternatives if the throbbing headaches are too bothersome.

Tell your doctor if you become pregnant while taking nitroglycerin.

Tell all your healthcare providers you are on nitroglycerin, especially before any surgery, including dental procedures

Nitroglycerin Drug Interactions

Certain drugs can affect how nitroglycerin works. Possible interactions between nitroglycerin and other medicines can increase the risk of severe adverse effects.

Tell your doctor if you are taking or have recently taken riociguat (Adempas), a medication prescribed for pulmonary hypertension, or PDE5 inhibitors like sildenafil (Viagra, Revatio), tadalafil (Cialis, Adcirca), and similar drugs used to treat erectile dysfunction. Your doctor may tell you not to take nitroglycerin with these medications.

Other drugs that can interact with nitroglycerin include:

  • Aspirin
  • Beta blockers like metoprolol (Toprol XL, Lopressor), labetalol (Trandate), atenolol (Tenormin), nadolol (Corgard), carteolol, propranolol (Inderal), timolol, and sotalol (Sorine, Betapace)
  • Calcium channel blockers like diltiazem (Cartia, Cardizem, Diltzac), amlodipine, verapamil (Covera, Calan, Verelan, in Tarka), felodipine (Plendil), nifedipine (Adalat, Procardia, Afeditab CR), and isradipine (DynaCirc)
  • Diuretics or water pills
  • Ergot drugs like cabergoline, bromocriptine (Parlodel, Cycloset), dihydroergotamine (Migranal, D.H.E. 45), ergotamine (in Cafergot, in Migergot), ergoloid mesylates (Hydergine), and methylergonovine (Methergine) 
  • Heparin
  • Medications used to treat high blood pressure, heart failure, and irregular heartbeat

This is not a complete list of nitroglycerin drug interactions. Give your doctor and pharmacist a list of all the medicines you take, including prescription drugs, over-the-counter drugs, dietary supplements, and herbal products. Also, tell your healthcare professionals if you smoke, drink alcohol, or use illegal drugs because some of these substances can cause serious health complications when used with prescription medications.