Contraindications for Nitroglycerin Administration
Nitroglycerin is contraindicated in patients with hypotension (SBP <90 mm Hg or ≥30 mm Hg below baseline), extreme bradycardia (<50 bpm), tachycardia in the absence of heart failure (>100 bpm), right ventricular infarction, and in patients taking phosphodiesterase-5 inhibitors. 1
Absolute Contraindications
- Hypotension: Do not administer nitroglycerin when systolic blood pressure is <90 mmHg or ≥30 mmHg below baseline 1
- Recent use of PDE-5 inhibitors: Avoid nitroglycerin within 12 hours of avanafil, 24 hours of sildenafil/vardenafil, or 48 hours of tadalafil due to risk of profound hypotension 1, 2, 3
- Right ventricular infarction: Nitroglycerin can cause dangerous preload reduction in these patients 1
- Extreme bradycardia: Contraindicated in patients with heart rate <50 bpm 1
- Tachycardia without heart failure: Contraindicated in patients with heart rate >100 bpm unless heart failure is present 1, 4
- Soluble guanylate cyclase stimulator use: Concomitant use with medications like riociguat is contraindicated due to risk of severe hypotension 2
- Early myocardial infarction: Listed as a contraindication in drug labeling 2
- Severe anemia: Can worsen oxygen delivery to tissues 2, 5
- Increased intracranial pressure: Nitroglycerin can further increase intracranial pressure 2, 5
- Known hypersensitivity to nitroglycerin or components of the formulation 2
Relative Contraindications and Cautions
- Pre-existing low blood pressure: Patients with borderline blood pressure are at higher risk for hypotension; the risk of hypotension is linearly correlated with initial systolic pressure 6, 4
- Volume depletion: Patients who may be volume-depleted are at increased risk for hypotension 2
- Concurrent alcohol use: May potentiate hypotensive effects 2
- Hypertrophic cardiomyopathy: Nitrate therapy may aggravate angina in these patients 2
- Glaucoma: Listed as a contraindication in some sources 5
Special Considerations for Nitroglycerin Administration
- Cocaine-associated chest pain: While nitroglycerin can be used to relieve cocaine-associated chest pain, benzodiazepines should be considered first-line therapy 1
- Monitoring requirements: Close monitoring of blood pressure and heart rate is essential when administering nitroglycerin, especially in higher-risk patients 3
- IV access: Having IV access prior to nitroglycerin administration is associated with fewer adverse events 7
- Elderly patients: Increased age is associated with higher odds of adverse events following nitroglycerin administration 7
Adverse Effects to Monitor
- Hypotension: Most common serious adverse effect, occurring in approximately 3% of patients 4
- Bradycardia with hypotension: Can occur unpredictably and may be severe 6
- Headache: Common side effect that may indicate drug activity 2
- Lightheadedness or dizziness: Particularly upon standing 2
- Tolerance: Can develop with continuous use; intermittent dosing with a nitrate-free interval is recommended 5
By carefully screening for these contraindications before administering nitroglycerin, clinicians can minimize the risk of adverse events and improve patient outcomes.