A Dry Powder Inhaler (DPI) delivers medication to the lungs as a fine, dry powder. Unlike Metered-Dose Inhalers (MDIs) that use a chemical propellant, the DPI is breath-actuated, meaning the user’s own inhalation force releases the medicine. This eliminates the need to coordinate a hand-press with a slow breath, but requires a strong, quick inhalation. Mastering the correct technique is paramount because insufficient inspiratory flow can lead to reduced drug delivery, preventing the medication from reaching the deep airways where it is needed.
Preparing the Device and Loading the Dose
Before using a DPI, confirm the device has an available dose of medication. Many modern inhalers are equipped with a dose counter or indicator, which should be checked. If the device uses single-dose capsules, carefully place a fresh capsule into the designated chamber, handling it only by the edges. Multi-dose DPIs, such as those with disk or reservoir systems, typically require twisting a base or clicking a lever to load the powder into the mouthpiece.
Hold the device level while preparing the dose to prevent the powder from spilling out. Before bringing the device to the mouth, exhale fully and slowly away from the inhaler. Avoid exhaling directly into the mouthpiece, as moisture from the breath can cause the fine powder particles to clump together. This clumping can clog the device and prevent the medicine from being properly dispersed, rendering the dose ineffective.
The Proper Inhalation Technique
Once the dose is prepared, the user should sit up or stand straight to ensure the lungs are positioned for maximum capacity. The mouthpiece should be placed in the mouth, and the lips must close tightly around it to create a sealed pathway. This tight seal ensures that all inhaled air is drawn through the device, which is necessary to generate the required flow rate.
The inhalation must be performed quickly, deeply, and forcefully through the mouth. This rapid, powerful breath creates the air turbulence needed to separate the drug from its carrier substance, such as lactose, and disperse the fine medication particles. This technique is distinctly different from the slow, steady breath required for a Metered-Dose Inhaler. Failure to inhale with sufficient force means the powder may not break up completely, decreasing the amount of medication that reaches the lower respiratory tract.
After the quick, deep inhalation, the inhaler should be removed from the mouth, and the breath must be held for five to ten seconds. This breath-hold allows the microscopic drug particles time to settle onto the walls of the airways within the lungs. If a ten-second hold is not possible, the user should hold their breath for as long as is comfortably possible. Finally, the user should exhale slowly away from the device.
Post-Use Care and Storage
Immediate action after a dose is delivered is especially important if the medication contains an inhaled corticosteroid. Rinsing the mouth and gargling with water is required to remove any residual steroid particles that may have settled in the mouth or throat. The rinse water must be spit out and not swallowed, as this practice helps prevent a localized fungal infection known as oral thrush, a common side effect of steroid inhalation.
The DPI should be securely closed immediately after use to protect the remaining doses from environmental contamination. If the device has a counter, a quick check should confirm that the number has advanced, verifying that the dose was successfully registered. For long-term maintenance, DPIs must be stored in a cool, dry place and kept away from heat and moisture. Never store the inhaler in a bathroom, as humidity can compromise the integrity of the dry powder.
Cleaning a DPI requires specific care because the internal mechanisms must remain completely dry. Never use water or any liquid to clean the device, as even a small amount of moisture can cause the powder to clump and ruin the entire inhaler. Instead, the mouthpiece should be wiped regularly with a clean, dry cloth or tissue to remove any residue.