A nurse is teaching a client about using a metered-dose rescue inhaler. Which of the following statements should the nurse include in the teaching?

A metered-dose inhaler (MDI) delivers a precise dose of medication directly into the lungs for rapid relief of bronchospasm in conditions such as asthma. Proper technique is essential to ensure optimal drug delivery to the lower airways and maximize therapeutic effect. Incorrect use can significantly reduce medication deposition and treatment effectiveness. Patient education focuses on coordinating breathing with inhaler activation and maintaining proper device hygiene. A. Using peroxide to clean the mouthpiece of the inhaler is not recommended because it may damage the device or leave residue that could be inhaled. The mouthpiece should instead be cleaned with warm water and allowed to air dry to maintain proper function and hygiene. B. Not shaking the inhaler before use is incorrect because shaking is necessary to mix the medication with the propellant, ensuring consistent and accurate dosing. Failure to shake the inhaler can result in uneven medication delivery and reduced effectiveness. C. Depressing the canister after inhalation is incorrect because the medication must be released at the start of inhalation to allow proper deposition into the lower airways. Delaying activation reduces drug delivery and limits therapeutic benefit. D. Exhaling fully before bringing the inhaler to the lips is correct because it helps empty the lungs, allowing for a deeper, more effective inhalation of the medication. This improves drug penetration into the bronchi and enhances therapeutic response. Proper breath coordination is essential for optimal inhaler use.