Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NITROGLYCERIN vs GONITRO
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Nitroglycerin is a vasodilator that is converted to nitric oxide (NO) in vascular smooth muscle cells. NO activates guanylyl cyclase, increasing c GMP levels, leading to dephosphorylation of myosin light chains and vasodilation. Predominantly dilates venous capacitance vessels, reducing preload; also dilates coronary arteries at higher doses.
Nitric oxide (NO) donor; activates guanylyl cyclase, increasing c GMP in vascular smooth muscle, leading to vasodilation.
Acute angina pectoris,Prophylaxis of angina pectoris,Acute myocardial infarction (IV formulation),Heart failure associated with acute myocardial infarction (IV),Anal fissure (topical, off-label),Esophageal spasm (off-label)
Prevention of angina pectoris due to coronary artery disease,Acute relief of angina episodes,Prophylaxis for angina before exertion or stress
Sublingual: 0.3-0.6 mg every 5 minutes up to 3 doses for angina; Transdermal: 0.2-0.8 mg/hour patch applied daily for 12-14 hours; Intravenous: 5-200 mcg/min continuous infusion for acute coronary syndromes or heart failure; Topical 2% ointment: 15-30 mg (0.5-1 inch) every 6-8 hours.
Sublingual: 0.3-0.6 mg at onset of angina, may repeat every 5 minutes up to 3 doses within 15 minutes. Prophylactic: 0.3-0.6 mg 5-10 minutes before activity. Transdermal: Apply 0.2-0.8 mg/hour patch once daily, remove at bedtime to prevent tolerance. Intravenous: Start at 5 mcg/min, titrate by 5-20 mcg/min every 3-5 minutes based on hemodynamic response; usual range 10-200 mcg/min.
Terminal half-life: 1–4 minutes for the parent compound; clinical effects dissipate within the same time frame, correlating with rapid metabolism.
Terminal elimination half-life approximately 2-3 minutes for nitroglycerin; clinical effects cease within 30-60 minutes due to rapid redistribution and metabolism
Metabolized primarily by hepatic glutathione-organic nitrate reductase and cytochrome P450 enzymes (CYP3A4) to inorganic nitrite and denitrated metabolites; also undergoes extrahepatic metabolism in erythrocytes and vascular tissue.
Extensively metabolized by mitochondrial aldehyde dehydrogenase (ALDH2) in vascular smooth muscle; also metabolized by glutathione S-transferases and cytochrome P450 (CYP3A4).
Metabolized extensively by hepatic glutathione-organic nitrate reductase and other non-specific esterases; renal excretion of metabolites accounts for approximately 50%, with fecal elimination of about 20-30%. Less than 1% of unchanged drug is excreted renally.
Primarily renal: 80-90% as inactive metabolites (dinitrates, mononitrates); minor biliary/fecal (<10%)
Approximately 60% bound to albumin.
60% bound, primarily to plasma albumin
Approximately 3.3 L/kg, indicating extensive distribution into tissues.
Approximately 3.3 L/kg; extensive tissue distribution with high affinity for vascular smooth muscle
Sublingual: 40–60% due to first-pass metabolism; buccal: 40–60%; transdermal: 10–20% (limited by skin permeability).
Sublingual: 40-60%; Oral (immediate-release): <10% due to first-pass hepatic metabolism; Transdermal: 70-90% (drug-in-adhesive); Intravenous: 100%
No dose adjustment required for any degree of renal impairment, including end-stage renal disease.
No specific dose adjustment required for renal impairment. However, use with caution in severe renal dysfunction (Cr Cl <30 m L/min) due to increased risk of hypotension and methemoglobinemia.
Child-Pugh Class A: No adjustment; Child-Pugh Class B: Consider 25% dose reduction; Child-Pugh Class C: Avoid use or use with extreme caution, consider 50% dose reduction.
Child-Pugh A: No adjustment needed. Child-Pugh B: Reduce dose by 50% due to decreased clearance. Child-Pugh C: Avoid use or use with extreme caution; consider alternative therapy.
Safety and efficacy not established; limited data: IV infusion 0.25-1 mcg/kg/min titrated to effect; sublingual 5-10 mcg/kg per dose (max 0.6 mg) every 5-10 minutes as needed for angina.
Sublingual: 5-10 mcg/kg/dose, maximum 0.3 mg per dose, may repeat every 5 minutes up to 3 doses. Intravenous: Start at 0.25-0.5 mcg/kg/min, titrate up to 1-5 mcg/kg/min based on response. Not recommended for children <1 year due to limited data.
Start at lowest dose; sublingual 0.3 mg, transdermal 0.2 mg/hour; increased sensitivity to hypotension and syncope; monitor for orthostatic hypotension; may require reduced dosing frequency.
Initiate at lower doses due to increased sensitivity: Sublingual: 0.15-0.3 mg; Transdermal: 0.2 mg/day patch; Intravenous: Start at 5 mcg/min, titrate slowly. Monitor for hypotension and syncope. Avoid sustained-release formulations due to prolonged half-life.
Do not use nitroglycerin with phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil, vardenafil) as this can cause severe hypotension. Concomitant use with soluble guanylyl cyclase stimulators (e.g., riociguat) is contraindicated.
Do not use with phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil) due to risk of severe hypotension.
Hypotension,Tachycardia,Paradoxical bradycardia,Increased intracranial pressure (use with caution in cerebral hemorrhage or head trauma),Hypertrophic cardiomyopathy (may exacerbate outflow obstruction),Tolerance with prolonged use (intermittent dosing with nitrate-free interval recommended),Abrupt withdrawal may precipitate angina
Hypotension (especially with volume depletion or diuretic therapy), reflex tachycardia, tolerance (intermittent dosing with nitrate-free interval recommended), abrupt discontinuation may cause angina rebound.
Hypersensitivity to nitroglycerin or any component,Concomitant use with phosphodiesterase-5 inhibitors (within 24 hours for sildenafil, vardenafil; 48 hours for tadalafil),Concomitant use with soluble guanylyl cyclase stimulators (riociguat),Severe anemia,Increased intracranial pressure (e.g., head trauma, cerebral hemorrhage),Constrictive pericarditis,Pericardial tamponade,Restrictive cardiomyopathy,Acute myocardial infarction with low left ventricular filling pressure,Circulatory failure (shock)
Concomitant use with PDE-5 inhibitors (sildenafil, tadalafil, vardenafil), severe anemia, increased intracranial pressure, hypersensitivity to nitrates, acute myocardial infarction with low filling pressure.
Avoid alcohol consumption while taking nitroglycerin due to risk of severe hypotension and syncope. No other significant food interactions.
Avoid alcohol consumption as it may exacerbate nitroglycerin-induced hypotension and vasodilation. No specific food interactions documented; however, patients should maintain adequate hydration. High-fat meals may delay absorption, but sublingual route minimizes this effect. Grapefruit juice has no known interaction.
Insufficient human data; animal studies do not indicate teratogenicity. Avoid in first trimester unless clearly needed. No known increased risk of major malformations. Use caution in third trimester due to potential maternal hypotension reducing uteroplacental perfusion.
FDA Pregnancy Category C. First trimester: no increased risk of major malformations in human studies; animal studies show fetal toxicity at high doses. Second/third trimesters: risk of fetal bradycardia, hypotension, and reduced uteroplacental perfusion; avoid near term due to risk of maternal hypotension and neonatal bradycardia.
Excreted into breast milk in very low amounts; M/P ratio not established. Considered compatible with breastfeeding; monitor infant for hypotension.
Not recommended during breastfeeding. No data on M/P ratio; minimal excretion into breast milk expected but safety not established. Potential for infant hypotension and bradycardia.
No routine dose adjustment required; however, increased plasma volume may necessitate higher doses for therapeutic effect. Monitor clinical response.
No standard dose adjustment required for pregnancy; use lowest effective dose. Increased plasma volume may reduce response; titrate to effect. Avoid in severe preeclampsia or volume depletion.
Use with caution in patients with hypertrophic obstructive cardiomyopathy due to risk of syncope. Nitroglycerin is contraindicated with phosphodiesterase-5 inhibitors (e.g., sildenafil) due to severe hypotension. Sublingual tablets should be taken at first sign of angina; if pain persists after 5 minutes, call 911. Tolerance develops with continuous exposure, so use nitrate-free intervals (10-12 hours daily) for transdermal patches. Administer intravenous nitroglycerin with non-PVC tubing to avoid drug absorption. Monitor for hypotension, reflex tachycardia, and headache. Do not use in patients with severe anemia, increased intracranial pressure, or right ventricular infarction.
GONITRO (nitroglycerin sublingual powder) is indicated for acute relief of angina pectoris. Administer one packet (0.4 mg or 0.8 mg) at onset of chest pain; may repeat every 5 minutes up to 3 doses. Ensure patient is seated or lying down to avoid hypotension. Do not confuse with oral spray; powder must be placed under tongue. Onset within 1-3 minutes. Common side effect: headache. Contraindicated with phosphodiesterase-5 inhibitors (e.g., sildenafil) within 24-48 hours due to severe hypotension. Monitor for orthostatic hypotension.
Take sublingual nitroglycerin at the first sign of chest pain; sit down before taking to prevent dizziness.,Place the tablet under the tongue or in the buccal pouch and allow it to dissolve completely; do not swallow.,If pain is not relieved within 5 minutes, call 911 immediately; you may take a second tablet while waiting.,Do not take this medication if you have taken erectile dysfunction drugs (e.g., sildenafil, tadalafil) within the last 24-48 hours.,Store sublingual tablets in the original glass bottle with the cap tightly closed to protect from light and moisture; do not transfer to another container.,Expect a headache or flushing after taking; these usually diminish with continued use.,If using a transdermal patch, apply to a hairless area of skin and rotate sites daily; remove at bedtime to prevent tolerance.,Avoid alcohol while taking this medication as it can increase the risk of hypotension.,Seek emergency help if you experience severe dizziness, fainting, or difficulty breathing.
Take one packet at the first sign of chest pain. Empty the entire powder under your tongue and let it dissolve. Do not swallow or rinse with water.,If pain persists after 5 minutes, take a second packet. If still no relief after 5 more minutes, take a third and call 911.,Sit or lie down when taking this medication to prevent dizziness or fainting.,Avoid alcohol; it may worsen side effects like low blood pressure.,Do not use Viagra, Cialis, Levitra, or other erectile dysfunction drugs while on this medicine—serious drop in blood pressure can occur.,Headaches are common; do not stop taking the medication. Over-the-counter pain relievers may help.,Store packets at room temperature away from moisture and heat. Do not open until ready to use.
"Concomitant use of nitroglycerin, a vasodilator that increases cyclic guanosine monophosphate (cGMP) in vascular smooth muscle, and acebutolol, a cardioselective beta-1 adrenergic blocker, can lead to excessive hypotension and reflex tachycardia. Acebutolol may blunt the compensatory sympathetic response to nitroglycerin-induced vasodilation, while nitroglycerin can counteract the negative chronotropic effects of acebutolol, resulting in unopposed vagal tone and potential bradycardia. This interaction increases the risk of syncope, dizziness, and cardiovascular collapse, particularly in patients with volume depletion or pre-existing heart failure."
"Amobarbital, a barbiturate with hepatic enzyme-inducing properties, may enhance the metabolism of nitroglycerin, potentially reducing its efficacy. However, the primary concern is that amobarbital can cause significant hypotension via central nervous system depression and vasodilation, which, when combined with the vasodilatory effects of nitroglycerin, may lead to additive hypotensive effects, increasing the risk of severe hypotension, syncope, and cardiovascular collapse. This interaction is particularly relevant in patients with coronary artery disease or heart failure, where maintaining adequate blood pressure is critical."
"Concurrent administration of clofarabine, a purine nucleoside antimetabolite, and nitroglycerin, a vasodilator for angina, may lead to additive hypotension. Clofarabine itself can induce hypotension as an adverse effect, and nitroglycerin directly relaxes vascular smooth muscle, resulting in decreased blood pressure. This combination increases the risk of severe hypotension, potentially leading to dizziness, syncope, or falls, especially in patients with pre-existing hypotension or volume depletion."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about NITROGLYCERIN vs GONITRO, answered by our medical review team.
NITROGLYCERIN is a Nitrate Vasodilator that works by Nitroglycerin is a vasodilator that is converted to nitric oxide (NO) in vascular smooth muscle cells. NO activates guanylyl cyclase, increasing c GMP levels, leading to dephosphorylation of myosin light chains and vasodilation. Predominantly dilates venous capacitance vessels, reducing preload; also dilates coronary arteries at higher doses.. GONITRO is a Nitrate Vasodilator that works by Nitric oxide (NO) donor; activates guanylyl cyclase, increasing c GMP in vascular smooth muscle, leading to vasodilation.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between NITROGLYCERIN and GONITRO depend on the specific clinical indication. These are both Nitrate Vasodilator agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of NITROGLYCERIN is: Sublingual: 0.3-0.6 mg every 5 minutes up to 3 doses for angina; Transdermal: 0.2-0.8 mg/hour patch applied daily for 12-14 hours; Intravenous: 5-200 mcg/min continuous infusion for acute coronary syndromes or heart failure; Topical 2% ointment: 15-30 mg (0.5-1 inch) every 6-8 hours.. The standard adult dose of GONITRO is: Sublingual: 0.3-0.6 mg at onset of angina, may repeat every 5 minutes up to 3 doses within 15 minutes. Prophylactic: 0.3-0.6 mg 5-10 minutes before activity. Transdermal: Apply 0.2-0.8 mg/hour patch once daily, remove at bedtime to prevent tolerance. Intravenous: Start at 5 mcg/min, titrate by 5-20 mcg/min every 3-5 minutes based on hemodynamic response; usual range 10-200 mcg/min.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between NITROGLYCERIN and GONITRO in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. NITROGLYCERIN is classified as Category C. Insufficient human data; animal studies do not indicate teratogenicity. Avoid in first trimester unless clearly needed. No known increased risk of major malformations. Use caution . GONITRO is classified as Category C. FDA Pregnancy Category C. First trimester: no increased risk of major malformations in human studies; animal studies show fetal toxicity at high doses. Second/third trimesters: ris. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.