Nitroglycerin Karo Pharma
Glyceryl Trinitrate Intravenous Infusion for Myocardial Ischaemia and Heart Failure
Quick Facts About Nitroglycerin Karo Pharma
Key Takeaways About Nitroglycerin Karo Pharma
- Hospital-only intravenous treatment: Nitroglycerin Karo Pharma is administered exclusively by healthcare professionals in hospital settings as a continuous IV infusion with careful blood pressure monitoring
- Rapid onset and offset: Effects begin within 1–2 minutes and cease within minutes of stopping the infusion, allowing precise haemodynamic control in critical care
- Absolute contraindication with PDE5 inhibitors: Must never be combined with sildenafil, tadalafil, or vardenafil due to risk of severe, life-threatening hypotension
- Special infusion equipment required: PVC tubing adsorbs nitroglycerin – polyethylene (PE) syringes and tubing must be used to ensure correct drug delivery
- Dose is individually titrated: Starting dose is 0.2–0.5 micrograms/kg/min, adjusted every 5 minutes based on blood pressure and heart rate response
What Is Nitroglycerin Karo Pharma and What Is It Used For?
Nitroglycerin Karo Pharma contains glyceryl trinitrate (GTN), a fast-acting vasodilator given as an intravenous infusion. It is used in hospital settings to treat myocardial ischaemia, acute heart failure, acute hypertensive emergencies, and for controlled hypotension during surgery.
Glyceryl trinitrate, commonly known as nitroglycerin, is one of the oldest and most important cardiovascular medications still in use today. Originally discovered in the mid-19th century, it has been used to treat heart-related conditions for over 140 years. The intravenous formulation manufactured by Karo Pharma provides a highly controllable method of delivering this drug in acute clinical settings where precise haemodynamic manipulation is essential.
The drug belongs to the class of organic nitrate vasodilators. When administered intravenously, glyceryl trinitrate acts as a prodrug that releases nitric oxide (NO) within vascular smooth muscle cells. This nitric oxide activates the enzyme guanylate cyclase, which increases levels of cyclic guanosine monophosphate (cGMP). The resulting cascade of intracellular events leads to relaxation of vascular smooth muscle, causing blood vessels to dilate. At low doses, nitroglycerin predominantly dilates venous capacitance vessels, which reduces the volume of blood returning to the heart (preload). At higher doses, it also dilates coronary arteries and arteriolar resistance vessels, reducing the resistance the heart must pump against (afterload).
In clinical practice, Nitroglycerin Karo Pharma is used in several key situations. For myocardial ischaemia – when the heart muscle is not receiving sufficient oxygen-rich blood – the drug reduces the heart’s workload while simultaneously improving coronary blood flow, thereby relieving ischaemic symptoms and reducing myocardial damage. This makes it an essential drug in the management of acute coronary syndromes, including unstable angina and acute myocardial infarction, where it is typically used alongside other treatments such as antiplatelet agents, anticoagulants, and beta-blockers.
For acute heart failure, intravenous nitroglycerin is used to rapidly reduce preload and afterload, thereby decreasing the congestion that causes breathlessness and pulmonary oedema. The European Society of Cardiology (ESC) 2023 Heart Failure Guidelines recommend IV nitrates as part of the acute management of patients with acute heart failure and elevated blood pressure, particularly those with signs of pulmonary congestion. In acute severe hypertension, the rapid and titratable blood pressure reduction offered by IV nitroglycerin makes it a valuable option. During certain surgical procedures, it is used to achieve controlled hypotension, reducing blood loss and improving the surgical field.
Glyceryl trinitrate is available in many different formulations worldwide, including sublingual tablets and sprays for acute angina, transdermal patches for chronic angina prevention, and rectal ointments for anal fissures. The Nitroglycerin Karo Pharma product discussed here is specifically the intravenous infusion formulation intended for hospital use, which provides the most rapid onset and the most precise dose titration of any glyceryl trinitrate formulation.
What Should You Know Before Receiving Nitroglycerin Karo Pharma?
Before administration, your medical team must be aware of all your medical conditions, current medications (especially PDE5 inhibitors such as sildenafil), and whether you have low blood pressure, pericardial disease, or increased intracranial pressure. Nitroglycerin Karo Pharma is contraindicated with phosphodiesterase type 5 inhibitors, cardiac tamponade, and constrictive pericarditis.
Contraindications
Your doctor will not give you Nitroglycerin Karo Pharma if any of the following apply:
- Allergy to glyceryl trinitrate or any of the other ingredients in this medicine, including ethanol, hydrochloric acid, sodium chloride, or water for injections
- Use of phosphodiesterase type 5 (PDE5) inhibitors such as sildenafil (used for erectile dysfunction and pulmonary hypertension), tadalafil, or vardenafil – this combination can cause a severe, potentially fatal drop in blood pressure leading to cardiovascular collapse
- Cardiac tamponade – a condition where fluid accumulates in the pericardial sac (the membrane surrounding the heart), compressing the heart and impeding its ability to pump blood
- Constrictive pericarditis – a chronic condition where the pericardium becomes thickened and rigid, restricting the heart’s ability to fill with blood
Nitroglycerin must never be used together with sildenafil (Viagra, Revatio), tadalafil (Cialis), vardenafil (Levitra), or any other PDE5 inhibitor. The combination can cause a catastrophic drop in blood pressure, potentially leading to myocardial infarction, stroke, or death. Patients must inform their medical team if they have taken any PDE5 inhibitor within the past 24–48 hours before receiving nitroglycerin.
Warnings and Precautions
When administering this medicine, your doctor will exercise particular caution and may adjust the dosing strategy if you have any of the following conditions:
- Low blood pressure (hypotension) – nitroglycerin further lowers blood pressure, which may cause dizziness, fainting, or cardiovascular compromise in already hypotensive patients. Systolic blood pressure should generally be maintained above 90 mmHg
- Cerebrovascular disease – conditions affecting the blood vessels of the brain may increase the risk of cerebral ischaemia if blood pressure drops too rapidly
- Raised intracranial pressure – nitroglycerin can dilate cerebral blood vessels, potentially worsening intracranial hypertension, particularly in patients with head trauma, haemorrhagic stroke, or brain tumours
- Heart valve disease (valvular stenosis) – particularly aortic and mitral stenosis, where the fixed cardiac output cannot compensate for the reduction in preload caused by nitrates, increasing the risk of syncope and haemodynamic collapse
- Anaemia – nitrates can cause methaemoglobinaemia, and pre-existing anaemia reduces the blood’s overall oxygen-carrying capacity, making patients more susceptible to tissue hypoxia
- Hypertrophic cardiomyopathy – the reduction in preload can worsen left ventricular outflow tract obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM)
- Impaired blood oxygenation (hypoxaemia) – nitroglycerin can worsen ventilation-perfusion mismatch in the lungs, potentially decreasing arterial oxygen levels
- Hypothyroidism – patients with reduced thyroid function may be more sensitive to the cardiovascular effects of nitrates
Pregnancy and Breastfeeding
There is limited clinical experience with the use of intravenous glyceryl trinitrate during pregnancy. Animal reproduction studies have not been conducted with this specific formulation. While glyceryl trinitrate has been used in obstetric settings (for example, as a uterine relaxant during certain emergency procedures), its routine use during pregnancy has not been established. If you are pregnant, suspect you may be pregnant, or are planning to become pregnant, your doctor will carefully weigh the potential benefits against the potential risks before administering this medicine.
It is not known whether glyceryl trinitrate or its metabolites are excreted in human breast milk. Given the short half-life of the drug (1–3 minutes) and its use in acute hospital settings, the clinical significance for breastfed infants is likely minimal. However, your medical team will make an individual assessment. Expressing and discarding breast milk during and for a short period after the infusion may be recommended as a precautionary measure.
Driving and Operating Machinery
As Nitroglycerin Karo Pharma is administered in a hospital setting, patients are typically not driving or operating machinery during treatment. However, the drug can cause dizziness, light-headedness, and postural hypotension (a drop in blood pressure upon standing), which may persist for some time after the infusion has been stopped. Patients should be advised not to drive or operate heavy machinery until these effects have fully resolved. The duration of impairment varies between individuals and depends on the dose and duration of the infusion.
Important Information About Excipients
Nitroglycerin Karo Pharma contains ethanol (alcohol) at a concentration of 12% by volume. Each millilitre of the solution contains 94.4 mg of alcohol. While the amount of alcohol delivered to patients at typical infusion rates is very low and unlikely to cause any noticeable effects, it should be taken into consideration in patients with alcohol dependence, liver disease, epilepsy, or in pregnant and breastfeeding women. The product also contains sodium chloride, but at less than 1 mmol (23 mg) per dose, making it essentially sodium-free. This is relevant for patients on strict sodium-restricted diets.
How Does Nitroglycerin Karo Pharma Interact with Other Drugs?
The most critical drug interaction is with PDE5 inhibitors (sildenafil, tadalafil, vardenafil), which is absolutely contraindicated. Nitroglycerin also interacts with other vasodilators, antihypertensive agents, heparin, and alteplase. All concurrent medications should be reviewed by the treating physician.
Because glyceryl trinitrate lowers blood pressure by dilating blood vessels, its effects can be dangerously amplified when combined with other medications that also lower blood pressure through various mechanisms. Additionally, nitroglycerin has specific pharmacokinetic interactions with certain drugs, particularly heparin, where it can reduce the anticoagulant effect. The clinical significance of these interactions is heightened in the critical care setting where patients are often receiving multiple medications simultaneously.
Major Interactions
| Drug | Category | Effect | Recommendation |
|---|---|---|---|
| Sildenafil / Tadalafil / Vardenafil | PDE5 Inhibitors | Severe, potentially fatal hypotension, myocardial infarction, stroke, and cardiovascular collapse | Absolutely contraindicated. Do not administer nitroglycerin within 24–48 hours of PDE5 inhibitor use |
| Heparin | Anticoagulant | Nitroglycerin may reduce the anticoagulant effect of heparin, requiring higher heparin doses to achieve the target aPTT | Monitor aPTT closely and adjust heparin dose accordingly. Re-check aPTT when nitroglycerin dose is changed or discontinued |
| Alteplase (tPA) | Thrombolytic | Nitroglycerin may reduce the thrombolytic efficacy of alteplase by decreasing hepatic blood flow and altering drug distribution | Use combination with caution; higher alteplase doses may be needed. Monitor treatment response closely |
Other Interactions to Be Aware Of
| Drug / Drug Class | Effect | Clinical Guidance |
|---|---|---|
| ACE inhibitors / ARBs | Additive blood pressure lowering; increased risk of symptomatic hypotension | Careful titration of nitroglycerin; frequent blood pressure monitoring |
| Beta-blockers | Enhanced hypotensive effect; beta-blockers may attenuate reflex tachycardia from nitrates | Often used therapeutically together in ACS management; monitor closely |
| Calcium channel blockers | Additive vasodilation and hypotension; particularly with dihydropyridines (e.g. amlodipine, nifedipine) | Monitor blood pressure frequently; reduce nitroglycerin infusion rate if needed |
| Diuretics | Additive hypotension due to volume depletion compounding nitrate-induced preload reduction | Ensure adequate volume status before starting nitroglycerin; monitor haemodynamics |
| Tricyclic antidepressants | Orthostatic hypotension may be potentiated | Use with caution; monitor blood pressure upon position changes |
| Alcohol (ethanol) | Enhanced vasodilation and hypotension; note that the product itself contains ethanol | Patients should not consume alcohol during or shortly after treatment |
This is not an exhaustive list of all potential interactions. In intensive care and perioperative settings, patients frequently receive multiple drugs with haemodynamic effects. The treating physician will review all concurrent medications and adjust the nitroglycerin infusion rate accordingly, guided by continuous haemodynamic monitoring.
What Is the Correct Dosage of Nitroglycerin Karo Pharma?
Nitroglycerin Karo Pharma is administered as a continuous intravenous infusion. The initial rate for adults is typically 0.2–0.5 micrograms/kg/minute, individually titrated based on blood pressure, heart rate, and clinical response. The dose is adjusted every 5 minutes until the desired effect is achieved.
Dosing of intravenous nitroglycerin is always individualised and guided by the patient’s clinical response, arterial blood pressure, and, where available, invasively measured cardiac filling pressures (such as pulmonary artery wedge pressure or central venous pressure). The drug is never given as a bolus injection; it is always administered as a continuous infusion to ensure smooth, controllable haemodynamic effects.
Adults
Standard Adult Dosing
The initial infusion rate is 0.2–0.5 micrograms/kg/minute. For controlled hypotension during surgery, a slightly higher initial rate may be used. After starting the infusion, the medical team waits approximately 5 minutes to observe the blood pressure and pulse response before making any dose adjustments. If blood pressure and heart rate remain stable after 5 minutes, the infusion rate is increased incrementally every 5 minutes until one of the following endpoints is reached:
- The desired clinical effect is achieved (e.g. resolution of chest pain, adequate blood pressure reduction, improved cardiac output)
- Blood pressure has decreased by approximately 10–15% from baseline
- Dose-limiting side effects appear (headache, excessive hypotension, reflex tachycardia)
For angina pectoris and heart failure, doses exceeding 2.5 micrograms/kg/minute are rarely required. For controlled surgical hypotension, doses up to 10 micrograms/kg/minute may occasionally be needed, though this is uncommon.
Preparation and Dilution
The solution can be administered undiluted (1 mg/ml) using a syringe pump, or diluted to 0.2 mg/ml by mixing 10 ml of Nitroglycerin Karo Pharma 1 mg/ml with 40 ml of 5% glucose or 0.9% sodium chloride (normal saline). No other medications should be added to the infusion solution. The prepared infusion solution should be used immediately and, for microbiological safety, no later than within 12 hours.
| Dose (mcg/kg/min) | 1 mg/ml (ml/kg/h) | 0.2 mg/ml (ml/kg/h) |
|---|---|---|
| 0.2 | 0.01 | 0.06 |
| 0.5 | 0.03 | 0.15 |
| 2.5 | 0.15 | 0.75 |
| 10 | 0.60 | 3.00 |
Children
The safety and efficacy of Nitroglycerin Karo Pharma in children have not been established in controlled clinical trials. In paediatric critical care practice, intravenous glyceryl trinitrate is occasionally used off-label in children with acute heart failure or after cardiac surgery, but dosing in these settings is specialist-driven and varies according to the individual clinical scenario. Paediatric dosing is typically in the range of 0.1–1 microgram/kg/minute, with careful titration guided by invasive haemodynamic monitoring.
Elderly Patients
Elderly patients may be more sensitive to the blood pressure-lowering effects of nitroglycerin due to reduced baroreceptor sensitivity, decreased intravascular volume, and altered vascular compliance. A lower initial infusion rate and more cautious titration are generally recommended. Blood pressure should be monitored particularly closely, and the patient should be assessed for signs of cerebral hypoperfusion such as confusion, drowsiness, or visual disturbances.
Stopping the Infusion
Nitroglycerin Karo Pharma should be gradually tapered rather than abruptly stopped, particularly after prolonged infusion or high-dose therapy. Sudden discontinuation can cause a rebound phenomenon – a rapid return or worsening of the original symptoms, especially in the coronary circulation. This can manifest as recurrence of angina, coronary vasospasm, or worsening heart failure. The infusion rate should be reduced in a stepwise fashion over an appropriate period, with continuous clinical monitoring.
Overdose
Because this medicine is given in a controlled hospital setting by trained medical professionals, overdose is unlikely. However, if an excessive dose were administered, symptoms would include severe headache, euphoria, skin flushing, cold sweats, nausea, vomiting, dizziness, syncope (fainting), cardiac arrhythmias, palpitations, and profound hypotension. In extreme cases, methaemoglobinaemia may occur, characterised by a blue-grey discolouration of the skin and mucous membranes due to the inability of blood to carry oxygen effectively.
Treatment of overdose involves immediately stopping the infusion, placing the patient in the Trendelenburg position (head down, legs elevated), and administering intravenous fluids. In severe cases, vasopressors such as norepinephrine may be required. For methaemoglobinaemia, methylene blue (1–2 mg/kg IV) is the specific antidote.
Nitroglycerin adsorbs to PVC (polyvinyl chloride) plastic. Standard PVC infusion sets can absorb 40–80% of the drug, drastically reducing the amount delivered to the patient. Polyethylene (PE) syringes and tubing must always be used. If tubing made from other plastics is used, it must have an internal PE coating. Failure to use appropriate equipment will result in unreliable dosing, potentially leading to treatment failure or sudden dose surges when sets are changed.
What Are the Side Effects of Nitroglycerin Karo Pharma?
The most common side effects are headache, dizziness, rapid heartbeat (tachycardia), low blood pressure (hypotension), and skin flushing. Most side effects are dose-related and resolve quickly when the infusion rate is reduced. A rare but serious side effect is methaemoglobinaemia.
Like all medicines, glyceryl trinitrate can cause side effects, although not everybody experiences them. The side effects of intravenous nitroglycerin are largely predictable consequences of its vasodilatory mechanism of action and are almost always dose-dependent. Because the drug is administered in a monitored hospital setting, side effects can be detected early and managed by adjusting the infusion rate.
Headache is the most frequently reported side effect and is caused by dilation of blood vessels within the brain (cerebral vasodilation). It typically occurs early in treatment and may diminish with continued therapy (a phenomenon known as nitrate tolerance). The headache can range from mild to severe and is usually responsive to simple analgesics such as paracetamol. If headache is debilitating, the infusion rate may need to be reduced.
Common
May affect up to 1 in 10 people
- Headache – the most frequent side effect, caused by cerebral vasodilation; often improves with continued use
- Dizziness – related to the blood pressure-lowering effect; may be worse when changing position (postural)
- Tachycardia (rapid heartbeat) – a compensatory reflex response to the drop in blood pressure
- Hypotension (low blood pressure) – dose-dependent; resolves rapidly when infusion rate is reduced
- Skin flushing – a feeling of warmth and reddening of the skin, particularly the face, neck, and chest
Uncommon
May affect up to 1 in 100 people
- Nausea – sometimes accompanied by a general feeling of unwellness; may be related to hypotension
Rare
May affect up to 1 in 1,000 people
- Methaemoglobinaemia – a blood disorder where the iron in haemoglobin is oxidised, reducing the blood’s ability to carry oxygen. Symptoms include blue-grey skin discolouration, shortness of breath, and confusion. This is more likely with prolonged, high-dose infusions. Treatment is intravenous methylene blue
- Syncope (fainting) – caused by severe hypotension or orthostatic changes; more common in volume-depleted patients
An important clinical consideration with prolonged IV nitroglycerin use is the development of nitrate tolerance. With continuous infusion over 24–48 hours or more, the body’s vascular response to nitroglycerin may diminish, requiring progressively higher doses to achieve the same haemodynamic effect. The exact mechanisms of tolerance are multifactorial and include depletion of intracellular sulphydryl groups, increased production of reactive oxygen species, and neurohormonal counter-regulatory activation. If tolerance develops, the medical team may consider a nitrate-free interval, alternative vasodilators, or dose escalation.
If you experience any side effects during or after treatment, inform your medical team immediately. Healthcare professionals are encouraged to report any suspected adverse reactions through their national pharmacovigilance system to help continuously monitor the benefit-risk profile of the medicine.
How Should Nitroglycerin Karo Pharma Be Stored?
Nitroglycerin Karo Pharma should be stored at controlled room temperature, protected from light, and kept out of the reach of children. Once diluted, the infusion solution should be used immediately and no later than within 12 hours for microbiological reasons.
This medicine must be stored out of sight and reach of children. As a hospital-use product, it is typically stored in pharmacy or ward medication storage areas under controlled conditions. Do not use this medicine after the expiry date stated on the carton and label. The expiry date refers to the last day of the stated month.
The product comes in clear glass injection vials (Type I glass), available in 10 ml vials (packs of 10) and 50 ml vials (packs of 1). Glass is used specifically because nitroglycerin does not adsorb to glass, ensuring the labelled concentration is maintained throughout the shelf life. The vials should be stored upright and protected from direct light, as nitroglycerin is sensitive to photodegradation.
Once diluted or transferred to a syringe for infusion, the solution should be used immediately. For microbiological safety, any prepared infusion that is not used immediately should be discarded after 12 hours. The diluted solution should not be refrigerated, as crystallisation may occur at low temperatures. The solution should be visually inspected before use and discarded if particulate matter or discolouration is observed.
What Does Nitroglycerin Karo Pharma Contain?
The active substance is glyceryl trinitrate at a concentration of 1 mg per ml. The solution also contains ethanol, hydrochloric acid, sodium chloride, and water for injections.
Active Ingredient
Each millilitre of Nitroglycerin Karo Pharma infusion solution and infusion concentrate contains 1 mg of glyceryl trinitrate (also known as nitroglycerin or GTN). Glyceryl trinitrate is the trinitrate ester of glycerol and has the molecular formula C3H5N3O9. It acts as a prodrug, releasing nitric oxide within the body to produce its therapeutic vasodilatory effects.
Other Ingredients (Excipients)
- Ethanol (alcohol) – used as a co-solvent to maintain glyceryl trinitrate in solution; present at 12% by volume (94.4 mg per ml)
- Hydrochloric acid – used for pH adjustment to ensure stability and compatibility
- Sodium chloride – for isotonicity adjustment; present in amounts less than 1 mmol (23 mg) per dose, making the product essentially sodium-free
- Water for injections – the pharmaceutical-grade solvent forming the base of the solution
Packaging
Nitroglycerin Karo Pharma is supplied in clear, colourless glass injection vials made from Type I glass (the highest pharmaceutical quality). Two presentations are available:
- 10 ml vials – containing 10 mg of glyceryl trinitrate per vial; supplied in packs of 10
- 50 ml vials – containing 50 mg of glyceryl trinitrate per vial; supplied as single vials
For larger infusion volumes at lower concentrations, a separate product – Nitroglycerin Karo Pharma Concentrate for Infusion 5 mg/ml – is available and recommended for administration using a volume pump. Regardless of which presentation is used, PVC-free infusion equipment must always be employed due to the adsorption issue described above.
Frequently Asked Questions
Both contain the same active ingredient (glyceryl trinitrate) but are used in different clinical situations. Sublingual nitroglycerin (tablets or spray placed under the tongue) is used for acute relief of angina episodes and is self-administered by patients. It has an onset of 1–3 minutes and a duration of about 20–30 minutes. Intravenous nitroglycerin, such as Nitroglycerin Karo Pharma, is used exclusively in hospital settings and provides continuous, precisely controllable vasodilation. It offers immediate onset and the ability to rapidly titrate the dose up or down based on moment-to-moment haemodynamic monitoring, making it ideal for acute coronary syndromes, heart failure, and perioperative blood pressure management.
No. You must inform your medical team immediately if you have taken sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), or any other PDE5 inhibitor within the past 24–48 hours. These drugs dramatically enhance the blood pressure-lowering effect of nitroglycerin, which can lead to a catastrophic drop in blood pressure resulting in heart attack, stroke, or death. Your medical team will use alternative treatments to manage your condition until the PDE5 inhibitor has been fully cleared from your system. This is one of the most important drug safety warnings in cardiovascular medicine.
Nitroglycerin causes headaches because it dilates blood vessels throughout the body, including those in the brain (meningeal arteries). This dilation stretches the pain-sensitive nerve endings in the vessel walls, triggering a headache. It is essentially the same mechanism that causes many types of vascular headache. The headache is typically dose-related – higher doses produce more intense headaches. In many patients, the headache improves with continued treatment as the body develops some degree of tolerance to the cerebral vasodilatory effects. Simple analgesics such as paracetamol can help manage the headache without interfering with the cardiovascular benefits of nitroglycerin.
Nitrate tolerance is a well-recognised clinical phenomenon where the blood vessels become progressively less responsive to nitroglycerin with prolonged, continuous exposure. This typically becomes clinically significant after 24–48 hours of continuous infusion, though individual variation exists. The mechanisms include depletion of intracellular sulphydryl groups needed for nitric oxide generation, increased production of superoxide radicals, and activation of counter-regulatory neurohormonal systems. When tolerance develops, higher doses are needed to achieve the same effect. Strategies to manage tolerance include nitrate-free intervals (not always practical in acute settings), dose escalation, or switching to alternative vasodilators. Tolerance reverses within 12–24 hours of discontinuing the infusion.
The duration of treatment varies depending on the clinical indication and your individual response. For acute coronary syndromes, IV nitroglycerin may be administered for 24–48 hours or until the patient is stabilised and can transition to oral or transdermal nitrate therapy. For acute heart failure, the infusion may continue until adequate diuresis has been achieved and the patient is no longer in respiratory distress. For controlled hypotension during surgery, the infusion is typically limited to the operative period. Your medical team will determine when it is appropriate to stop or taper the infusion based on your clinical progress.
Yes, glyceryl trinitrate is chemically the same substance discovered by Ascanio Sobrero in 1847, which Alfred Nobel later used to create dynamite. However, the amounts used in medicine are far too small to have any explosive properties. The pharmaceutical formulation is heavily diluted in a solution at a concentration of just 1 mg/ml, making it completely safe for medical use. Interestingly, Nobel himself suffered from angina and was reportedly reluctant to take nitroglycerin prescribed by his doctor, noting the irony. The medical use of nitroglycerin predates the full understanding of its mechanism of action, which was only fully elucidated in the 1990s when the role of nitric oxide in vascular biology was discovered – work that earned Robert Furchgott, Louis Ignarro, and Ferid Murad the 1998 Nobel Prize in Physiology or Medicine.
References and Sources
- European Society of Cardiology (ESC). “2023 ESC Guidelines for the management of acute coronary syndromes.” European Heart Journal, 2023. doi: 10.1093/eurheartj/ehad191
- European Society of Cardiology (ESC). “2023 Focused Update of the 2021 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure.” European Heart Journal, 2023. doi: 10.1093/eurheartj/ehad195
- Amsterdam EA, Wenger NK, Brindis RG, et al. “2014 AHA/ACC Guideline for the Management of Patients with Non–ST-Elevation Acute Coronary Syndromes.” Journal of the American College of Cardiology, 2014;64(24):e139–e228. doi: 10.1016/j.jacc.2014.09.017
- National Institute for Health and Care Excellence (NICE). “Acute coronary syndromes: NICE guideline [NG185].” 2020 (updated 2023).
- Münzel T, Daiber A, Gori T. “Nitrate Therapy: New Aspects Concerning Molecular Action and Tolerance.” Circulation, 2011;123(19):2132–2144. doi: 10.1161/CIRCULATIONAHA.110.981407
- World Health Organization (WHO). “WHO Model List of Essential Medicines – 23rd List.” 2023.
- British National Formulary (BNF). “Glyceryl trinitrate.” National Institute for Health and Care Excellence, 2024.
- Cohn JN, Franciosa JA. “Vasodilator Therapy of Cardiac Failure.” New England Journal of Medicine, 1977;297(1):27–31.
- Furchgott RF, Zawadzki JV. “The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine.” Nature, 1980;288:373–376.
- European Medicines Agency (EMA). “Glyceryl trinitrate – Summary of Product Characteristics.” Accessed February 2026.
About the Medical Editorial Team
Board-certified cardiologists, intensivists, and clinical pharmacologists with expertise in cardiovascular pharmacotherapy and critical care medicine. All content is reviewed according to international guidelines including ESC, AHA/ACC, and WHO standards.
Evidence Level 1A based on systematic reviews, meta-analyses, and randomised controlled trials. All clinical claims are supported by peer-reviewed references. Content is reviewed at least annually and updated whenever new guideline recommendations are published.
This article was written by the iMedic Medical Editorial Team and reviewed by our Medical Review Board in accordance with our editorial standards. iMedic receives no commercial funding. We have no conflicts of interest with any pharmaceutical company.