What is the preferred method for administering GTN to a patient experiencing angina?

The preferred method for administering GTN (glyceryl trinitrate) to a patient experiencing angina is under the tongue, known as sublingual administration. This method is favored because it allows for rapid absorption of the medication into the bloodstream through the mucous membranes in the mouth.

When GTN is taken sublingually, it bypasses the gastrointestinal tract and the first-pass metabolism in the liver, allowing it to act quickly. This is crucial in acute situations such as angina attacks, where immediate relief from chest pain is necessary. The onset of action is typically within a few minutes, making it an effective choice for managing sudden angina symptoms.

Though other administration routes exist, such as orally, intramuscularly, and topically, these are not as effective for immediate relief in an acute setting. Oral administration may take longer to work due to digestion, intramuscular injections can be slower, and topical applications usually require more time for absorption and may not provide as acute relief as sublingual doses.