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Nitroglycerin
Aka: Nitroglycerin, Antianginal
- History
- Albert Nobel stabilized Nitroglycerin for dynamite
- Some postulate that he died of Nitroglycerin toxicity
- Preparations
- Short Acting Nitroglycerin
- Long Acting Nitroglycerin
- Intravenous Nitroglycerin
- Indications
- Angina Pectoris
- Acute Myocardial Infarction
- Left Ventricular Failure (Congestive Heart Failure)
- Contraindications
- Aortic Stenosis
- Pulmonary Hypertension
- Hypotension
- Phosphodiesterase Inhibitor (e.g. Viagra)
- Right sided Myocardial Infarction (seen with inferior Myocardial Infarction)
- Mechanism
- Relaxes vascular Smooth Muscle
- Venous Dilation (more than Nitroprusside)
- Inhibits venous return (Preload)
- Decreases intra-myocardial wall tension
- Decreases intraventricular work
- Reduces left ventricular filling pressure
- Decreases myocardial oxygen demand
- Reduces Myocardial Ischemia
- Cardiac Output
- Increased in Congestive Heart Failure
- Decreased or normal if no Heart Failure
- Arterial Dilation (less than Nitroprusside)
- Relieves Angina
- Dilates large coronary arteries
- Antagonizes vasospasm
- Increases coronary collateral Blood Flow
- Increases perfusion to ischemic Myocardium
- Decreases Systemic Vascular Resistance
- Esophageal Spasm also responds to nitrates
- Pain relief with Nitroglycerin is not always Angina
-
Drug Interactions
- Phosphodiesterase Inhibitors (e.g. Viagra or Sildenafil)
- Profound hypotensive reaction
- Do not use with Nitroglycerin!
- Nitrates may be used >24 hours after Sildenafil or vardenafil or >48 hours after Tadalafil
- Tissue Plasminogen Activator (Alteplase, tPA)
- IV Nitroglycerin may reduce plasma concentrations
- Heparin
- IV Nitroglycerin may reduce Anticoagulant response
- Adverse Effects
- Headache
- Hypotension
- High risk with Aortic Stenosis, Pulmonary Hypertension, Hypotension, PDE5 Inhibitor, right-sided Myocardial Infarction
- Reduce Nitrate dose
- Administer Intravenous Fluid bolus
- Consider Atropine if Bradycardia present
- Methemoglobinemia
- Hypoxemia (Ventilation-perfusion mismatch)
- References
- Orman and Mattu in Herbert (2017) EM:Rap 17(7): 6-7