Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
NITROL vs GONITRO
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
NITROL (nitroglycerin) is a vasodilator that relaxes vascular smooth muscle via the release of nitric oxide (NO), which activates guanylate cyclase and increases cyclic guanosine monophosphate (c GMP) levels, leading to vasodilation.
Nitric oxide (NO) donor; activates guanylyl cyclase, increasing c GMP in vascular smooth muscle, leading to vasodilation.
Treatment of acute angina pectoris,Prophylaxis of angina pectoris (pre-exertional use),Management of acute myocardial infarction (FDA-approved),Congestive heart failure (off-label, in acute settings)
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 as needed for angina, up to 3 doses in 15 minutes. Translingual spray: 1-2 sprays (0.4 mg/spray) under tongue every 5 minutes as needed, max 3 doses in 15 minutes. Transdermal: 0.2-0.8 mg/hour patch applied daily for 12-14 hours. Intravenous: Initial 5 mcg/min, titrate by 5 mcg/min every 3-5 minutes until response, usual range 10-200 mcg/min.
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.
1-4 minutes for nitroglycerin; clinical effect disappears within 30-60 minutes due to rapid metabolism and redistribution.
Terminal elimination half-life approximately 2-3 minutes for nitroglycerin; clinical effects cease within 30-60 minutes due to rapid redistribution and metabolism
Primarily metabolized by nitrate reductase in the liver; also undergoes denitration by glutathione-dependent organic nitrate reductase and by hemoglobin in red blood cells.
Extensively metabolized by mitochondrial aldehyde dehydrogenase (ALDH2) in vascular smooth muscle; also metabolized by glutathione S-transferases and cytochrome P450 (CYP3A4).
Renal: minimal, <1% unchanged; extensive metabolism by liver, metabolites excreted renally. Biliary/fecal: negligible.
Primarily renal: 80-90% as inactive metabolites (dinitrates, mononitrates); minor biliary/fecal (<10%)
Approximately 60% bound to albumin.
60% bound, primarily to plasma albumin
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% (first-pass metabolism); Oral: <10% due to high first-pass; Transdermal: ~20-30% with continuous delivery; Intravenous: 100%.
Sublingual: 40-60%; Oral (immediate-release): <10% due to first-pass hepatic metabolism; Transdermal: 70-90% (drug-in-adhesive); Intravenous: 100%
No specific adjustment for GFR; monitor for hypotension and methemoglobinemia in severe impairment. Use with caution in dialysis patients.
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 A: No adjustment. Child-Pugh B: Reduce dose by 50% and titrate carefully. Child-Pugh C: Avoid use or use with extreme caution, consider alternative therapy.
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.
Sublingual/translingual: 5 mcg/kg/dose every 5-10 minutes as needed for acute angina, max 4 doses. IV: Start 0.25-0.5 mcg/kg/min, titrate by 0.5-1 mcg/kg/min, max 5 mcg/kg/min. Not recommended for neonates due to risk of methemoglobinemia.
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 low end of adult dose (sublingual 0.3 mg, transdermal 0.2 mg/hr, IV 5 mcg/min). Titrate slowly due to increased sensitivity and risk of hypotension. Monitor for orthostatic hypotension.
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.
Contraindicated in patients with erectile dysfunction who are using phosphodiesterase-5 (PDE-5) inhibitors (e.g., sildenafil, tadalafil) due to risk of severe hypotension.
Do not use with phosphodiesterase-5 inhibitors (e.g., sildenafil, tadalafil) due to risk of severe hypotension.
Risk of severe hypotension and syncope, especially in volume-depleted patients or those with low systolic blood pressure; tolerance and cross-tolerance with other nitrates may develop; abrupt cessation may precipitate angina; caution in patients with hypertrophic obstructive cardiomyopathy.
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; severe anemia; increased intracranial pressure (e.g., head trauma, cerebral hemorrhage); concurrent use with PDE-5 inhibitors; right ventricular infarction; constrictive pericarditis; cardiac tamponade.
Concomitant use with PDE-5 inhibitors (sildenafil, tadalafil, vardenafil), severe anemia, increased intracranial pressure, hypersensitivity to nitrates, acute myocardial infarction with low filling pressure.
Alcohol can exacerbate hypotensive effects and should be avoided. No specific food restrictions; however, high-fat meals may delay sublingual absorption but not clinically significant.
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.
FDA Pregnancy Category C. No adequate studies in pregnant women. In animal studies, nitroglycerin has been shown to be embryotoxic in rats and rabbits at doses 20 times the human dose. Use in first trimester only if clearly needed. During second and third trimesters, may be used for management of preterm labor or pregnancy-induced hypertension, but monitor for maternal hypotension and fetal bradycardia.
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.
Not known if nitroglycerin is excreted in human milk. M/P ratio not available. Because of potential for serious adverse reactions in nursing infants, discontinue nursing or discontinue drug, taking into account importance of drug to mother. Use with caution if breastfeeding; avoid high doses or continuous exposure.
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 specific dose adjustments recommended for pregnancy-related PK changes. However, increased plasma volume and cardiac output in pregnancy may require higher doses for therapeutic effect. Start at lowest effective dose and titrate based on clinical response and blood pressure. For intravenous use in pregnancy, standard non-pregnant doses may be used but with careful titration.
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.
Nitrol (nitroglycerin) is a potent vasodilator used primarily for angina pectoris. Sublingual tablets should be administered at first sign of attack; patient should be sitting to prevent syncope from hypotension. If pain persists after 3 doses 5 minutes apart, seek emergency care. Tolerance develops with sustained use; avoid long-acting formulations for acute episodes. Monitor for orthostatic hypotension and headache, common side effects. Contraindicated with concurrent use of PDE-5 inhibitors (e.g., sildenafil) due to risk of severe hypotension.
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; do not swallow. Place tablet under tongue and allow to dissolve.,Sit down before taking to avoid fainting due to drop in blood pressure.,If pain is not relieved after 1 dose, take a second dose after 5 minutes. If not relieved after 3 doses, call 911 immediately.,Store tablets in original glass container, tightly closed, away from light and heat. Replace every 6 months as potency decreases.,Avoid alcohol and erectile dysfunction drugs (e.g., Viagra, Cialis) as they can cause severe hypotension.,Common side effects include headache, dizziness, and flushing. Headache may indicate effectiveness.
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.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about NITROL vs GONITRO, answered by our medical review team.
NITROL is a Nitrate Vasodilator that works by NITROL (nitroglycerin) is a vasodilator that relaxes vascular smooth muscle via the release of nitric oxide (NO), which activates guanylate cyclase and increases cyclic guanosine monophosphate (c GMP) levels, leading to vasodilation.. 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 NITROL 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 NITROL is: Sublingual: 0.3-0.6 mg every 5 minutes as needed for angina, up to 3 doses in 15 minutes. Translingual spray: 1-2 sprays (0.4 mg/spray) under tongue every 5 minutes as needed, max 3 doses in 15 minutes. Transdermal: 0.2-0.8 mg/hour patch applied daily for 12-14 hours. Intravenous: Initial 5 mcg/min, titrate by 5 mcg/min every 3-5 minutes until response, usual range 10-200 mcg/min.. 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 NITROL 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. NITROL is classified as Category C. FDA Pregnancy Category C. No adequate studies in pregnant women. In animal studies, nitroglycerin has been shown to be embryotoxic in rats and rabbits at doses 20 times the human d. 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.