Inhaler device

Inhaler devices are used as delivery systems for respiratory medications. They are indicated for:

Approved Indications

• Asthma (mild, moderate, severe): For delivering bronchodilators, corticosteroids, and combination therapies to manage airway inflammation and bronchospasm.
• Chronic Obstructive Pulmonary Disease (COPD): Maintenance therapy with long-acting bronchodilators or corticosteroids.
• Exercise-Induced Bronchospasm: Prevention and control of symptoms.
• Allergic Rhinitis with Lower Airway Involvement: Delivery of anti-inflammatory agents.
• Bronchiectasis (with associated airway hyperreactivity): For delivering mucolytic or bronchodilator therapy.

Off-label (Clinically Accepted) Uses

• Cystic Fibrosis: For inhaled antibiotics and mucolytics.
• Pulmonary Hypertension (select cases): Inhaled prostacyclin analogs.
• Post-Lung Transplant Airway Care: Inhaled immunosuppressants.

General Principle: Dosage depends on the medication inside the inhaler (e.g., corticosteroid, bronchodilator). However, proper technique and device selection are critical for optimal drug delivery.

Administration Techniques by Device Type

• Metered-Dose Inhaler (MDI): Shake well before use, exhale fully, seal lips around the mouthpiece, press the canister while inhaling deeply and slowly, hold breath for 10 seconds.
• Dry Powder Inhaler (DPI): Load dose, exhale away from device, inhale forcefully and deeply, hold breath for 10 seconds.
• Soft Mist Inhaler: Twist base to load, press button while inhaling slowly and deeply.
• Nebulizer: Use mask or mouthpiece, breathe normally during nebulization for 5–10 minutes.

Frequency & Duration

• Typically 1–2 inhalations per dose, frequency depends on drug class (e.g., short-acting bronchodilator: every 4–6 hours as needed; long-acting bronchodilator: once or twice daily).

Special Populations

• Children: Use a spacer with MDIs for better delivery.
• Elderly: Simplify regimen, ensure dexterity for handling device.
• Renal/Hepatic Impairment: Adjust only if drug requires.

The inhaler device itself has no pharmacological action; it serves as a delivery system that converts liquid or powder medication into an aerosol or mist for inhalation. This enables the drug to reach the lower respiratory tract directly, allowing rapid onset, reduced systemic absorption, and targeted effect on bronchial smooth muscle or airway inflammation.

Not applicable to the device itself. However, inhalation delivery provides:

• Rapid Onset: Drug reaches lungs within seconds.
• High Local Concentration: Minimal systemic absorption for many drugs.
• Reduced First-Pass Effect: Bypasses hepatic metabolism.
• Shorter Half-life in systemic circulation compared to oral administration.

• Device Safety: Inhalers themselves are considered safe during pregnancy and breastfeeding as they are drug delivery systems.
• Drug Considerations: Most inhaled corticosteroids and bronchodilators have minimal systemic absorption and are generally considered safe during pregnancy and lactation. Always confirm based on the specific drug.

• Category: Drug delivery device for respiratory therapy.
• Sub-class: Metered-Dose Inhalers (MDIs), Dry Powder Inhalers (DPIs), Soft Mist Inhalers (SMIs), Nebulizers.

As the device is not pharmacologically active, contraindications relate to the medication inside:

• Hypersensitivity to components of the inhaled drug formulation.
• Inability to coordinate inhalation and actuation (for MDIs without spacer).
• Severe cognitive or physical impairment preventing proper device use.

• Incorrect technique may lead to suboptimal drug delivery.
• Always check the dose counter (if present) to avoid running out of medication.
• Avoid washing DPIs with water.
• Replace mouthpiece cover after each use to maintain hygiene.
• Rinse mouth after inhaled corticosteroid use to prevent oral thrush.

Inhaler devices themselves have minimal side effects; most are related to the medication delivered:

• Local: Dry mouth, throat irritation.
• With corticosteroids: Oral candidiasis (thrush).
• Mechanical Issues: Mouthpiece injury if misused.
• Rare: Hypersensitivity to device materials (e.g., plastic components).

• Device-related: None clinically significant.
• Drug-specific: Interactions depend on medication inside the inhaler (e.g., beta-agonists with beta-blockers, corticosteroids with CYP3A4 inhibitors).

• Global Initiative for Asthma (GINA 2024): Recommends inhaled corticosteroids as first-line therapy, delivered via inhaler devices.
• COPD GOLD 2024 Update: Prefers long-acting bronchodilators via inhalers for maintenance therapy.
• New Devices: Breath-actuated inhalers and smart inhalers for better adherence.

• Store in a cool, dry place at 20°C to 30°C.
• Keep away from direct sunlight and moisture.
• Do not freeze.
• For MDIs: Do not puncture or expose to heat/fire (pressurized canister).
• Keep mouthpiece clean and dry.
• Check expiration date and replace if past due.