Unstable angina / non ST elevation myocardial infarction nitrate therapy


 * Associate Editors-In-Chief: ; Varun Kumar, M.B.B.S.; Lakshmi Gopalakrishnan, M.B.B.S.; Smita Kohli, M.D.;

Mechanism of Benefit

 * Nitroglycerin (NTG), an endothelium-independent vasodilator, has both peripheral and coronary vascular effects.
 * By venodilation, it decreases the myocardial preload, ultimately, decreasing the myocardial oxygen demand.
 * It also dilates the coronary arteries, thus, decreasing the amount of stenosis and relieves pain.
 * In addition, it promotes collateral flow and redistribution of coronary blood flow to ischemic regions.

Dosing

 * If three sublingual 0.4mg tablets of NTG fail to relieve the pain, intravenous NTG may be initiated along with oral or intravenous beta blocker.

Indications

 * It will also be helpful in patients with heart failure and hypertension.

==ACC / AHA Guidelines (DO NOT EDIT) ==

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Class I
1. Patients with Unstable angina / NSTEMI with ongoing ischemic discomfort should receive sublingual NTG (0.4 mg) every 5 min for a total of 3 doses, after which assessment should be made about the need for intravenous NTG, if not contraindicated. (Level of Evidence: C)

2. Intravenous NTG is indicated in the first 48 h after Unstable angina / NSTEMI for treatment of persistent ischemia, heart failure, or hypertension. The decision to administer intravenous NTG and the dose used should not preclude therapy with other proven mortality reducing interventions such as beta blockers or ACE inhibitors. (Level of Evidence: B)

Class III
1.Nitrates should not be administered to Unstable angina / NSTEMI patients with systolic blood pressure <90mmHg or ≥30 mmHg below baseline, severe bradycardia (<50 bpm), tachycardia (>100 bpm) in the absence of symptomatic heart failure, or right ventricular infarction. (Level of Evidence: C)

2.Nitroglycerin or other nitrates should not be administered to patients with Unstable Angina / NSTEMI who had received a phosphodiesterase inhibitor for erectile dysfunction within 24 h of sildenafil or 48 h of tadalafil use. The suitable time for the administration of nitrates after vardenafil has not been determined. (Level of Evidence: C)}}