What is the best treatment for immediate relief of angina symptoms?

From the Guidelines

Sublingual nitroglycerine is the strongest and most effective treatment for immediate relief of angina symptoms. According to the 2024 ESC guidelines for the management of chronic coronary syndromes 1, sublingual nitroglycerine is frequently prescribed to treat anginal pain symptoms, with rapid relief expected within 1 or 2 minutes. For acute angina attacks, sublingual nitroglycerin tablets or nitroglycerin spray should be administered under the tongue. Key points to consider when administering nitroglycerin include:

• The patient should sit down before taking nitroglycerin, as it can cause lightheadedness or dizziness due to blood pressure drops
• Relief typically occurs within 1-5 minutes
• The dose can be repeated at 5-minute intervals up to a maximum of three doses if pain persists
• If chest pain continues after three doses, emergency medical services should be called immediately as this may indicate a heart attack Nitroglycerin works by dilating blood vessels, improving blood flow to the heart muscle and reducing the workload on the heart, addressing the underlying cause of angina, which is insufficient oxygen supply to the heart muscle relative to demand 1. Patients with angina should keep nitroglycerin readily available at all times and replace it regularly according to expiration dates, as the medication can lose potency over time.

From the FDA Drug Label

The principal pharmacological action of nitroglycerin is relaxation of vascular smooth muscle. Although venous effects predominate, nitroglycerin produces, in a dose-related manner, dilation of both arterial and venous beds Nitroglycerin sublingual tablets are intended for sublingual or buccal administration and should not be swallowed.

The nitroglycerin sublingual is likely stronger than the paste for immediate relief of angina symptoms because it is administered sublingually and is rapidly absorbed.

• The onset of the vasodilatory effect occurs approximately 1 to 3 minutes after sublingual nitroglycerin administration and reaches a maximum by 5 minutes postdose.
• Maximum plasma nitroglycerin concentrations (Cmax) and area under the plasma concentration-time curves (AUC) increase dose-proportionally following 0.3 to 0.6 mg nitroglycerin 2. However, the paste formulation is not described in the provided drug labels, so no direct comparison can be made. The decision of which formulation to use should be based on individual patient needs and medical professional guidance. 2

From the Research

Comparison of Nitro Sublingual and Paste

• Nitro sublingual and paste are both forms of nitroglycerin used for immediate relief of angina symptoms 3, 4, 5.
• Sublingual nitroglycerin is considered suitable for the immediate relief of angina, as it maintains its full anti-ischemic effect both after initial oral ingestion and after intermittent long-term oral administration 3.
• There is no direct comparison between nitro sublingual and paste in terms of strength, but sublingual nitroglycerin is often considered the most effective antianginal agent due to its rapid onset of action 5.

Mechanism of Action

• Nitroglycerin works by converting to nitric oxide in the body, leading to venodilation and arteriodilation, which results in both preload and afterload reduction 6.
• This mechanism of action helps to reduce myocardial oxygen demand and improve collateral blood flow in ischemic areas 5.

Tolerance and Efficacy

• Long-acting nitrates, including nitro paste, can develop tolerance or attenuation with repeated dosing, which can limit their efficacy 3, 4, 5.
• Sublingual nitroglycerin, on the other hand, maintains its efficacy even with long-term use, but its short duration of action can limit its prophylactic use 5.
• Carefully designed dosing regimens and/or appropriate use of nitrate formulations can help decrease or eliminate the problem of nitrate tolerance 4.