Organic nitrate
ATC code: C01DA02 (Glyceryl trinitrate)
Brand names
Nitrostat, Nitro-Bid, Nitro-Dur, Nitrolingual, Nitromist
Releases nitric oxide that relaxes vascular smooth muscle. Decreases pre- and afterload, dilates coronary arteries. Used for angina attacks and acute heart failure. Absolutely contraindicated with PDE-5 inhibitors (sildenafil, etc.) due to severe hypotension.
First line
Sublingual or intravenous nitroglycerin is used in acute coronary syndrome to reduce myocardial ischemia, control hypertension, and relieve pulmonary congestion. Intravenous infusion (start at 5–10 mcg/min, titrate to BP and pain) is indicated for ongoing ischemia, hypertension, or heart failure. Avoided in systolic BP below 90 mm Hg, right-ventricular infarction, and after recent phosphodiesterase-5 inhibitor use.
Second line
In acute decompensated heart failure with pulmonary congestion and preserved arterial perfusion, intravenous nitroglycerin lowers preload, reduces dyspnea, and unloads the left ventricle. 2023 recommends use in patients with systolic BP above 110 mm Hg. Start infusion at 10–20 mcg/min with titration by BP and symptoms. Avoided in cardiogenic shock and systolic BP below 90 mm Hg.
First line
Sublingual nitroglycerin 0.3–0.6 mg or spray is the drug of choice for terminating a stable angina episode. Onset is 1–3 minutes, duration 20–30 minutes. / 2023 and 2024 recommend that every patient with stable CAD carry a sublingual formulation. If pain persists 5 minutes after the first dose, call emergency services – the picture may represent acute coronary syndrome. Prophylactic use 5–10 minutes before anticipated exertion is acceptable.
Sources
First line
Long-acting nitrates (nitroglycerin ointment, patch, sustained-release tablets, or isosorbide mono/dinitrate) prevent attacks in Prinzmetal vasospastic angina. 2023 recommends combined calcium channel blockers and long-acting nitrates as baseline therapy. A 8–12-hour nitrate-free interval is preserved between doses to prevent tolerance.
The drug is promoted for these uses outside international guidelines. Each entry below is analyzed against AEMPS, FDA, EMA, Cochrane and major RCTs.
Not recommended
Nitroglycerin is an organic nitrate and potent vasodilator. It is prescribed for acute angina relief and acute left heart failure ( 2024). In sports circles, nitroglycerin is occasionally promoted to improve blood flow to muscles before training. In healthy athletes without ischemic heart disease, no clinical studies of prophylactic use exist, and such use is dangerous. The drug has specific risks: severe hypotension with syncope, headache (common, marked), tolerance with regular use, and dangerous blood pressure drop combined with PDE5 inhibitors (sildenafil, tadalafil – strictly contraindicated). If nitroglycerin was prescribed to an athlete for training, consider seeking a second opinion.
4 pairs found. Sorted from critical to minor.
Mechanism
Sildenafil blocks phosphodiesterase-5, slowing breakdown of cGMP – the intracellular mediator of vascular relaxation. Nitroglycerin raises cGMP production. Co-administration sharply amplifies vasodilation – severe systemic hypotension develops. Fatal cases have been reported.
Symptoms
Sudden drop in blood pressure: dizziness, visual greying, syncope, shock. In ischaemic heart disease, risk of myocardial infarction from coronary perfusion collapse.
Management
The combination is not prescribed. After sildenafil, nitrates are permitted only after 24 hours. After tadalafil (long-acting), only after 48 hours. In acute coronary syndrome after recent sildenafil, replace nitrates with morphine and oxygen; for preload reduction, use furosemide.
Sources
Opens the checker prefilled with this drug. Pick the second one from your regimen.
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Nitroglycerin is evaluated for the following indications with varying evidence strength: Heart failure with reduced ejection fraction (evidence tier A), Stable angina pectoris (evidence tier A), Acute coronary syndrome (evidence tier A). See the full indication matrix with dosing and citations above on this page.
Common side effects of Nitroglycerin (≥ 1 in 100): Headache (throbbing, resolves in 20–30 minutes or after several doses), Facial flushing, sensation of warmth, Hypotension, orthostatic reactions, Reflex tachycardia, Dizziness. See the Safety section for uncommon and serious reactions.
FDA category C. FDA category C. In pregnancy, nitroglycerin is used for acute coronary syndrome, acute pulmonary edema, hypertensive emergencies with pulmonary edema, and acute tocolysis in uterine hyperstimulation. Decision is made by a specialized team.
Data on nitroglycerin transfer into human milk are limited. A single sublingual dose is considered compatible with breastfeeding. With long-term nitrate therapy, alternatives are considered.
Nitroglycerin is contraindicated in: Systolic BP below 90 mm Hg; PDE5 inhibitors within 24 hours (sildenafil, vardenafil) or 48 hours (tadalafil); Riociguat (a guanylate cyclase stimulator); Right-ventricular myocardial infarction; Cardiogenic shock and severe hypovolemia. Full list in the Safety section.
Mechanism
Additive hypotension with sublingual nitroglycerin. Alprazolam sedation may worsen dizziness.
Symptoms
Lower blood pressure, postural dizziness, fatigue. Older patients: fall risk.
Management
The patient takes the first nitroglycerin dose sitting or lying down. Warn the patient about fall risk after nitroglycerin while on alprazolam.
Mechanism
Additive orthostatic hypotension with sublingual nitroglycerin. Amitriptyline blocks α1-adrenoceptors and reduces compensatory response.
Symptoms
Postural dizziness, syncope, fatigue. Older patients: fall and fracture risk.
Management
The patient takes the first nitroglycerin dose sitting or lying down. Older patients: enhanced fall monitoring. Alternative antidepressants without α1-blockade: sertraline or agomelatine.
Mechanism
Additive hypotension with sublingual or parenteral nitroglycerin. Both drugs are vasodilators (amlodipine – calcium channel blocker, nitroglycerin – nitrate vasodilator).
Symptoms
Lower blood pressure, postural dizziness, fatigue. Older patients: fall risk.
Management
The combination is acceptable in angina. The patient takes the first nitroglycerin dose sitting or lying down. Older patients: fall risk after nitroglycerin. Advise the patient to consult a clinician with frequent episodes.
FDA category C. In pregnancy, nitroglycerin is used for acute coronary syndrome, acute pulmonary edema, hypertensive emergencies with pulmonary edema, and acute tocolysis in uterine hyperstimulation. Decision is made by a specialized team.
Data on nitroglycerin transfer into human milk are limited. A single sublingual dose is considered compatible with breastfeeding. With long-term nitrate therapy, alternatives are considered.
Reference information, not a clinical decision. Discuss feeding pauses or changes with your physician or an IBCLC.
sublingual formulations do not cause addiction – they are used episodically. Tolerance is a pharmacological phenomenon of continuous exposure (24-hour patch, sustained-release without breaks), not situational use.
throbbing headache is an expected adverse effect of peripheral vasodilation. It resolves in 20–30 minutes or after several uses with partial tolerance to this effect.
if pain persists 5 minutes after the first dose, call emergency services. This may be acute coronary syndrome requiring thrombolysis or PCI, not more nitrate.