What is the first Drug of Choice in Myocardial Infarction?

Uttarakhand CHO - 2021

Pharmacology

Easy

Appeared in: Uttarakhand CHO - 2021

Explanation

Sorbitrate (Isosorbide dinitrate) is an organic nitrate, a class of drugs used to relieve anginal chest pain.
It acts as a potent vasodilator, primarily dilating veins to reduce cardiac preload (the volume of blood returning to the heart).
This reduction in preload decreases the heart's workload and myocardial oxygen demand, alleviating ischemia.
Sublingual administration provides rapid onset of action (within 2-5 minutes), making it ideal for acute attacks.
While Aspirin is the first life-saving drug, nitrates are the first-line choice for symptomatic pain relief from the given options.

Option B: Signoflam is a combination drug containing an NSAID. NSAIDs are contraindicated in acute MI because they increase the risk of cardiovascular events, impair healing of the infarcted tissue, and can increase mortality.
Option C: Salbutamol is a bronchodilator used for asthma. It stimulates beta-2 receptors, but also has some beta-1 effects, leading to an increased heart rate (tachycardia) and contractility. This would increase the oxygen demand of the heart muscle, worsening the myocardial ischemia.
Option D: Soda-Bicarbonate (Sodium Bicarbonate) is an alkalinizing agent. It is not used in the routine initial management of MI. Its use is reserved for specific situations like treating severe metabolic acidosis, which might occur during a cardiac arrest, but it does not address the underlying cause of the MI.

Clinical Relevance

Nursing practice connection: Knowing Pharmacological management of acute Myocardial Infarction (MI) helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
A nurse's primary role in suspected MI is rapid assessment and intervention. Administering sublingual nitrate is a key skill, but it must be preceded by a blood pressure check.
Patient safety is paramount. Nitrates are contraindicated if the systolic BP is below 90 mmHg or if the patient has recently taken a phosphodiesterase-5 inhibitor (e.g., sildenafil for erectile dysfunction), as this combination can cause life-threatening hypotension.
What if? If a patient's chest pain is not relieved after three doses of sublingual nitrate given 5 minutes apart, the nurse should not administer more. Instead, the priority is to administer prescribed opioid analgesics like morphine and immediately notify the physician, as this may indicate a large or ongoing infarction requiring more aggressive intervention like PCI.

How to Approach the Question

First, identify the core of the question: it asks for the 'first drug of choice' for Myocardial Infarction from a specific list of options.
Analyze the patient's condition: Myocardial Infarction is a state of severe cardiac ischemia (lack of oxygen) causing chest pain.
Evaluate each drug option based on its primary mechanism and indication.
Option A (Sorbitrate): Recognize this as a nitrate, a known vasodilator used to relieve angina. This is a plausible answer.
Option B (Signoflam): Identify this as an NSAID. Recall that NSAIDs are contraindicated in MI.
Option C (Salbutamol): Identify this as a bronchodilator that increases heart rate and oxygen demand, which would be harmful in MI.

Concept Tested & Keywords

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E6 Pharmacology Nurses Shanbhag 3e p. 112-114

E6 Pharmacology KD Tripathi Essentials 9e Part 2 pp. 222-224, 233-235