Nitroglycerin Infusion Guidelines for Acute Angina or Myocardial Infarction

Initial Dosing and Titration

The American College of Cardiology recommends starting intravenous nitroglycerin at 10 mcg/min and titrating upward by 10 mcg/min every 3-5 minutes until symptoms resolve or blood pressure responds, with a commonly used ceiling of 200 mcg/min 1, 2
When using non-absorbing tubing, begin at 5-10 mcg/min through an infusion pump capable of exact delivery 1, 2
Increase the infusion rate by 10 mcg/min every 3-5 minutes for the first 20 minutes until symptom relief or blood pressure response occurs 1, 2
If no response at 20 mcg/min, use larger increments of 10 mcg/min, then 20 mcg/min 1, 2
Once partial response is achieved, reduce the increment size and lengthen the interval between increases 1, 2
Stop titrating if symptoms resolve—no need to continue increasing for blood pressure effect alone 1, 2

The commonly recommended ceiling is 200 mcg/min, though this is not an absolute limit 1, 2, 3
Prolonged infusions at 300-400 mcg/min have been safely administered for 2-4 weeks without increasing methemoglobin levels 1, 2
If doses exceed 200 mcg/min, consider switching to alternative vasodilators 4

Do not use if systolic BP <90 mmHg or >30 mmHg below baseline 1, 2, 3
Target systolic BP: Not less than 110 mmHg in normotensive patients 1, 2, 3
In hypertensive patients, do not reduce mean arterial pressure by more than 25% 1, 2
Right ventricular infarction: Use with extreme caution or avoid entirely, as these patients depend critically on preload 4, 3
Phosphodiesterase inhibitor use: Contraindicated within 24 hours of sildenafil or 48 hours of tadalafil due to risk of profound hypotension and death 1, 2, 3
Marked bradycardia or tachycardia is a contraindication 1, 2, 3

Tolerance develops after 24 hours of continuous infusion and is dose and duration dependent 1, 2, 3
Increase infusion rate periodically if therapy extends beyond 24 hours 1, 2
Transition to oral/topical nitrates within 24 hours once patient is stable and symptom-free for 12-24 hours 1, 2
Use lower doses and intermittent dosing when possible to minimize tolerance 1, 2
Consider nitrate-free intervals if ischemia recurs during continuous therapy 1, 2

The American Heart Association recommends avoiding the use of intravenous nitroglycerin in patients taking phosphodiesterase inhibitors within 24 hours of sildenafil or 48 hours of tadalafil due to the risk of profound hypotension and death 5

Tolerance to intravenous nitroglycerin develops after 24 hours of continuous infusion and is dose and duration dependent, according to the American College of Cardiology 5

The American Heart Association recommends intravenous nitroglycerin for patients whose symptoms are not relieved with three 0.4-mg sublingual nitroglycerin tablets taken 5 minutes apart 5
Intravenous nitroglycerin is indicated for all nonhypotensive high-risk patients with acute coronary syndrome, as recommended by the American College of Cardiology 5
The American Heart Association suggests that intravenous nitroglycerin may be administered along with morphine sulfate for unrelieved symptoms, with careful blood pressure monitoring 5
The American College of Cardiology recommends combining intravenous nitroglycerin with beta-blockers when not contraindicated 5