Which of the following statements about administering glyceryl trinitrate spray is correct?

• A. Spray directly under the tongue and close mouth immediately after use
• B. Spray under the tongue and swallow immediately after use
• C. Spray into the nostril
• D. Inhale the spray through the mouth

Answer: (A)

Glyceryl trinitrate spray is used for rapid relief of angina when given sublingually. Placing the spray under the tongue allows quick absorption through the oral mucosa into the bloodstream, providing fast onset without first-pass metabolism in the liver. Keeping the mouth closed after administration helps maximize local absorption rather than swallowing the drug, which would reduce bioavailability and delay effect. Spraying into the nostril or inhaling through the mouth are not appropriate routes for this preparation, and swallowing immediately would diminish the rapid onset that's needed.