Nitroglycerin

Aka: Nitroglycerin, Antianginal

1. History
   1. Albert Nobel stabilized Nitroglycerin for dynamite
      1. Some postulate that he died of Nitroglycerin toxicity
2. Preparations
   1. Short Acting Nitroglycerin
   2. Long Acting Nitroglycerin
   3. Intravenous Nitroglycerin
3. Indications
   1. Angina Pectoris
   2. Acute Myocardial Infarction
   3. Left Ventricular Failure (Congestive Heart Failure)
4. Mechanism
   1. Relaxes vascular smooth muscle
   2. Venous Dilation (more than Nitroprusside)
      1. Inhibits venous return (preload)
         1. Decreases intra-myocardial wall tension
         2. Decreases intraventricular work
      2. Reduces left ventricular filling pressure
         1. Decreases myocardial oxygen demand
         2. Reduces Myocardial Ischemia
      3. Cardiac output
         1. Increased in Congestive Heart Failure
         2. Decreased or normal if no Heart Failure
   3. Arterial Dilation (less than Nitroprusside)
      1. Dilates large coronary arteries
      2. Antagonizes vasospasm
      3. Increases coronary collateral blood flow
         1. Increases perfusion to ischemic Myocardium
      4. Decreases systemic vascular resistance
   4. Esophageal Spasm also responds to nitrates
      1. Pain relief with Nitroglycerin is not always Angina
5. Drug Interactions
   1. Viagra (Sildenafil)
      1. Profound hypotensive reaction
      2. Do not use with Nitroglycerin!
   2. Tissue Plasminogen Activator (Alteplase, tPA)
      1. IV Nitroglycerin may reduce plasma concentrations
   3. Heparin
      1. IV Nitroglycerin may reduce Anticoagulant response
6. Adverse Effects
   1. Headache
   2. Hypotension
      1. Symptoms
         1. Nausea
         2. Syncope
         3. "Giddiness"
      2. Management
         1. Reduce Nitrate dose
         2. Administer Intravenous Fluids
         3. Administer Atropine if Bradycardia present
   3. Methemoglobinemia
   4. Hypoxemia (Ventilation-perfusion mismatch)