A transdermal nitroglycerin patch is prescribed. Which instruction should be included in teaching?

• A. Apply the patch to a nonhairy area of the upper torso or arm.
• B. Apply the patch to the same site each day.
• C. If you have a headache, remove the patch for 4 hours and then reapply.
• D. If you have chest pain, apply a second patch next to the first patch.

Answer: (A)

Applying the patch to a nonhairy area of the upper torso or arm is best because transdermal nitroglycerin delivers a steady amount of medication through the skin, and hair, skin folds, or rough surfaces can interfere with adhesion and lead to unpredictable absorption. Keeping the site clean, dry, and hairless helps ensure consistent dosing and reduces skin irritation. It’s also important to rotate sites daily to prevent dermatitis and to avoid tolerance from always using the same skin area.

Other teaching points to accompany this include not placing a second patch for chest pain, since that can cause dangerous hypotension and isn’t how acute symptoms are managed; use the prescribed fast-acting nitroglycerin instead and seek medical help if chest pain persists. If headaches occur, some clinicians advise removing the patch for a period and then reapplying, but the exact duration should follow the provider’s instructions to balance relief with maintaining antianginal effect.