What happens when you take alcohol with nitroglycerin?
Nitroglycerin is the original nitrate medication, used to relieve angina (chest pain caused by reduced blood flow to the heart) and, in hospital settings, to manage very high blood pressure and acute heart failure. Alcohol also relaxes and widens blood vessels, especially at higher blood levels. Because both substances lower blood pressure through overlapping mechanisms, taking them close together can produce a larger fall in blood pressure than either alone.
- Nitroglycerin releases nitric oxide in blood vessel walls. This relaxes the smooth muscle of veins and, to a lesser extent, arteries, reducing the work the heart has to do and relieving angina, often within minutes for the sublingual forms.
- Alcohol adds its own vessel-widening effect. When alcohol is already in the bloodstream, the body's vessels are already somewhat dilated, so a dose of nitroglycerin lands on top of that and pushes blood pressure down further.
- The combined drop reduces blood flow to the brain. The classic picture is a flushed feeling, a throbbing headache, and lightheadedness within minutes of a sublingual dose taken after drinking.
- In people with significant coronary disease, the low pressure can be counterproductive. If blood pressure falls too far, blood flow to the heart muscle itself can drop, which can worsen rather than relieve the chest pain nitroglycerin is meant to treat. Severe drops can cause fainting and falls.
This pairing has been recognized for a long time. One of the earliest formal reports of the interaction appeared as a clinical letter in the New England Journal of Medicine in 1965, describing fainting in patients who combined nitroglycerin with alcohol.
Why is this important?
People who are prescribed nitroglycerin generally have coronary artery disease, and many have a heart that tolerates sudden blood pressure changes less well than a healthy person's. A drop that a healthy drinker would barely notice can leave them faint or unsteady.
The timing of nitroglycerin use adds a particular trap. Nitroglycerin is often taken situationally at the moment chest pain starts, rather than on a fixed daily schedule. Someone who has had a couple of drinks at dinner and then develops angina afterward may reach for a sublingual tablet without thinking about the alcohol already on board. If the resulting lightheadedness is misread as the heart problem getting worse, a person may take more nitroglycerin and push their blood pressure down further.
People who use long-acting nitrates such as isosorbide mononitrate or isosorbide dinitrate for daily angina prevention face a slightly different version of the same issue: some nitrate is present in the body most of the time, so heavier drinking adds a continuous blood-pressure-lowering effect rather than a single spike.
A separate and serious concern is the combination of any nitrate with an erectile-dysfunction drug in the PDE5 inhibitor class (such as sildenafil, tadalafil, or vardenafil). Taking a nitrate within the window after one of these drugs can cause a dangerous fall in blood pressure. Alcohol can make this scenario more likely by lowering inhibitions and adding its own vessel-widening effect.
What should you do?
The simplest, safest approach for someone prescribed nitroglycerin is to avoid alcohol or to drink only lightly. Many stable patients tolerate a small amount of alcohol with a meal, but more than that meaningfully raises the chance of a problematic blood pressure drop if nitroglycerin is needed. Use the schedule below as a practical guide, and confirm what is right for you with your own doctor or pharmacist.
Before you drink: If you have an active nitroglycerin prescription, plan ahead. Decide whether to skip alcohol entirely or keep it light and paired with food, and make sure your nitroglycerin is with you in case chest pain occurs.
Every day / on an ongoing basis: If you use a long-acting nitrate for daily angina prevention, keep alcohol intake light and consistent rather than occasional heavy drinking, since the nitrate is always present. Carry a current medication list so that bystanders and first responders know what you take. Never take a PDE5 inhibitor while on any nitrate.
If chest pain develops after drinking: Sit or lie down before placing a sublingual tablet or using the spray, and have someone with you if possible. Follow your prescribed nitroglycerin instructions, but do not keep taking more doses if you feel faint or your blood pressure has clearly dropped. Call emergency services if the chest pain does not ease, if you feel like you might pass out, or if you develop shortness of breath, sweating, nausea, or confusion. If you have recently taken a PDE5 inhibitor, tell responders so they can choose a treatment other than a nitrate.
Which specific products are affected?
The interaction applies to all forms of nitroglycerin, including sublingual tablets (Nitrostat), sublingual and translingual sprays (Nitrolingual, NitroMist), transdermal patches (Nitro-Dur, Minitran), topical ointment (Nitro-Bid), and intravenous nitroglycerin used in hospitals. The fast-acting sublingual tablets and sprays produce the quickest and most pronounced blood pressure drop, so they tend to interact most dramatically with alcohol already on board.
Other nitrates carry the same interaction: isosorbide dinitrate (Isordil, Dilatrate-SR) and isosorbide mononitrate (Imdur, Monoket, ISMO). Riociguat (Adempas), used for pulmonary hypertension, works on a related pathway and shares the strict contraindication with PDE5 inhibitors along with added blood-pressure-lowering risk. Amyl nitrite, sometimes encountered recreationally, has the same mechanism and is particularly hazardous combined with alcohol or PDE5 inhibitors.
On the alcohol side, any beer, wine, or spirits can contribute, particularly when consumed at a meal or event where nitroglycerin might be needed.
The science behind it
The foundation of this interaction is straightforward pharmacology: nitroglycerin and alcohol are both vasodilators, and their effects on blood pressure add together. Clinical references describe nitroglycerin's mechanism and note that concurrent alcohol can cause additive low blood pressure.
- Hartshorn EA. Hypotension Due to Nitroglycerin Combined with Alcohol. N Engl J Med. 1965;273(21):1163. An early clinical letter describing fainting from the combination. View source
- Kim KH, et al. Nitroglycerin. StatPearls, NIH/NCBI Bookshelf (NBK482382). A clinical reference review confirming nitroglycerin's vasodilator mechanism and the additive low-blood-pressure effect with alcohol. View source
- Nitroglycerin Disease/Drug Interactions, Drugs.com. Drug interaction reference describing counseling on additive low blood pressure when nitrates are combined with alcohol. View source
These sources agree on direction and mechanism. The evidence base is largely mechanistic and clinical-experience based rather than large trials, which is appropriate given that the additive blood-pressure effect is well understood and would be unethical to test deliberately in vulnerable patients.
Frequently Asked Questions
Can I ever drink alcohol if I take nitroglycerin?
Many stable patients can tolerate a small amount of alcohol with food, but heavier drinking raises the risk of a blood pressure drop if nitroglycerin is needed. Ask your own doctor whether any alcohol is advisable given your heart condition.
Why does the combination make me feel faint?
Both substances widen blood vessels and lower blood pressure. Together they can reduce blood flow to the brain enough to cause lightheadedness or fainting, often within minutes of a sublingual dose taken after drinking.
What should I do if I get chest pain after a few drinks?
Sit or lie down first, then follow your prescribed nitroglycerin instructions. Do not keep taking doses if you feel faint, and call emergency services if the pain does not ease or you feel like you might pass out.
Is the interaction worse with sublingual tablets than with patches?
Fast-acting sublingual tablets and sprays cause the quickest and largest blood pressure drop, so they tend to interact most noticeably with alcohol. Patches and ointments act more gradually, but the same additive effect applies.
Why is mixing nitrates with erectile-dysfunction drugs so dangerous?
PDE5 inhibitors such as sildenafil, tadalafil, and vardenafil amplify the same blood-vessel-relaxing pathway that nitrates use. Combining them can cause a severe, potentially life-threatening fall in blood pressure, so they must never be taken together. Alcohol can make such combinations more likely.
Does this apply to long-acting nitrates too?
Yes. With daily nitrates such as isosorbide mononitrate or dinitrate, some medication is present most of the time, so heavier drinking adds a continuous blood-pressure-lowering effect rather than a single spike.
Key takeaways
- Nitroglycerin and alcohol both widen blood vessels, so together they can lower blood pressure enough to cause dizziness, fainting, or worsened chest pain.
- People on nitroglycerin often have heart disease and less tolerance for a sudden blood pressure drop, which makes the combination riskier for them than for a healthy person.
- If you drink, keep it light and with food, and sit or lie down before using a sublingual tablet or spray.
- Never combine any nitrate with a PDE5 inhibitor erectile-dysfunction drug; tell emergency responders if you have recently taken one.
- Seek emergency care if chest pain or faintness does not resolve quickly, and review what is right for your regimen with your doctor or pharmacist.