INHALATION THERAPY FOR ASTHMA AND COPD DR TINKU JOSEPH Resident Dept of pulmonary medicine Dy patil medical college

AEROSOL THERAPY DURING THE ANCIENT TIMES 3000 BC until 400 BC (Egyptian period) Asthma caused by Demons, spirits, foreign gods Treatment Prayers, Sacrifices Offerings to Gods, spells Burning incense to please Gods

INHALATION OF FUMES FROM DATURA PLANT (Asthma Bidis / Cigarettes) 2000 BC INDIA Datura Stramonium

ROMAN HOT WATER SPRINGS Healing effects of water and steam inhalation for various respiratory illness A Roman Hot Water Spring Temple, UK

ARABS - Water-Seal SMOKING PIPES

DISCOVERY OF THE PRESSURIZED METERED DOSE INHALER March 1955 SUSIE MASON, 13 year old asthmatic ‘Why can’t they put my asthma medication in a spray can like they do for my mothers hair sprays?’ Dr Maison who worked with Riker Labs (now 3M) ran to Irving, a Chemist with this idea. - Coca Cola bottle - Meshberg Valve - Freon Propellant - ice cream freezer - Ascorbic Acid First clinical trial – 1956 by Carr at Veterans Hospital in California. Launched in March 1956 (Medihaler-Epi, Medihaler-Iso). Today – more than 800 million pMDIs are sold every year.

AEROSOLS DEFINITION: Aerosol is the suspension of fine solid or liquid particles in air. The size of the particles should be sufficiently large not to diffuse like gas molecules and sufficiently small to remain air borne for sometime.

ADVANTAGE OF AEROSOL THERAPY IN ASTHMA Deposition of the drug directly at the local site Faster onset of action Lower dose of medication required Lower side effects

Aerosol Therapy for asthma and COPD The success of therapy using aerosolized medicine depends on the ability to deliver adequate amounts of drug to the lungs with few side effects

Deposition pattern of drugs DEVICE AEROSOL FORMULATION PATIENT FACTORS AND TECHNIQUE

Particle size and airway deposition > 5 m 2-5 m <2 m

DEPOSITION OF AEROSOLS SIZE (MMAD) SITE <0.5 U Stable (no deposition) 0.5-2 U Alveoli 2-5 U Bronchi & bronchioles 5-100 u Mouth, nose & upper airway >100 u Filtered by URT

AEROSOL GENERATION SYSTEMS Jet and Ultrasonic nebulizers Pressurized metered dose inhalers (pMDIs), with or without spacers (static and non static) Dry powder inhalers (DPIs): Unit dose and Multidose

Pressurized METERED DOSE INHALER

PARTS Cannister Drug Propellant Surfactant Metering valve Nozzle Mouth piece Protective cover

TECHNIQUE

Pressurized METERED DOSE INHALER ADVANTAGES DISADVANTAGES Portable &compact Rx time is short No drug preparation required Dose-dose reproducibility high No contamination of contents Coordination of breathing and actuation needed High pharyngeal deposition Cold Freon effect Remaining doses difficult to determine Potential for abuse Many use CFC

pMDI can cause thermal / chemical burns 11 year old boy with chronic asthma Repeatedly firing his Salbutamol MDI with the noozle placed directly against the skin – firing up to 10 times at one time (Patel R et al, Arch Dis Childhood 2004; 89: 1129)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            

Autohaler Reduces need for hand mouth coordination by firing in response to patients inspiratory efforts. Usage: In patients with poor MDI technique use of autohaler increased lung deposition. Used in : older patients with severe airflow obstruction Arthritis

Use of a spacer device Chamber reservoir where the actuated aerosol can be held prior to inhalation. Attached to an MDI. Amount of drug delivered is increased by using a spacer. First developed by Newman et al as a device that reduced oropharyngeal deposition in 1981 (Newman et al, Am Rev Respir Dis 1981; 124: 317-320)

ACE Spacer Inspirease Spacer Aerochamber EZ Spacers

Indications In patients who are unable to use pMDI. To reduce risk of adverse effects with inhaled medications. To decrease or eliminate coughing or arrested respiration experienced by some patients. To administer inhaled medication during severe exacerbations as recommended by ATS

Technique

spacer device DISADVANTAGES ADVANTAGES Reduces need for patient co-ordination Reduces pharyngeal deposition. Reduces cold Freon effect More expensive Less portable Can reduce dose available if not used properly Inhalation can be more complex for some patients Some patients find them embarassing to use in public

Zerostat V spacer

Zerostat VT spacer

Face mask

DRY POWDER INHALERS Single dose Multi-dose - Reservoir - Singlet Handihaler Rotahaler Single dose Multi-dose - Reservoir - Singlet Turbohaler Diskhaler Accuhaler

DRY POWDER INHALERS COMPONENTS: DEVICE: (Rotahaler /Spinhaler / Turbuhaler/ Diskhaler) DRUG RESERVIOR:- discrete gelatin capsules(Rotacaps,transcaps,multidose strips)

DRY POWDER INHALERS ADVANTAGES: Breath actuated – no co-ordination skills required Easy and convenient to use No propellant – environmentally friendly DISADVANTAGES: Requires a good inspiratory effort Carries a single dose at a time Capsule and drug life reduced by moisture and humidity can result in high pharyngeal deposition DRY POWDER INHALERS

Creates a fine mist of the drug which can be inhaled ADVANTAGES: Creates a fine mist of the drug which can be inhaled Does not require co-ordination or a minimum inspiratory pressure DISADVANTAGES: Unpredictable lung dose Inefficient lung deposition Bulky Expensive NEBULIZERS Ultrasonic Jet

NEBULIZER

Respule

(Fink JB, Respir Care 2000; 45(6): 623-635) (2,500 mcg) (200 mcg) (200 mcg) (200 mcg) (Fink JB, Respir Care 2000; 45(6): 623-635)

WHICH IS THE BEST INHALER DEVICE?

ASK THE PATIENT Assess the inhaler technique Prime importance to correct inhaler technique

AGE AS A DETERMINING FACTOR Children < 2 years - nebuliser Children 2-5 years - MDI with spacer with face mask Children > 5 years - DPI, MDI with spacer Children > 12 years - MDI alone (if suitable), DPI Very old people - DPI or breath actuated MDI

WHAT IS IN THE FUTURE?

PREVIEW – LOOKING INTO THE FUTURE Antibiotics Inhaled Insulin for management of Diabetes Morphine Growth factors Vasopressin

AEROSOL THERAPY FOR ASTHMA IN INDIA Asthma – grossly under-diagnosed in India Amongst diagnosed asthmatics - < 10% use inhaler therapy Misconceptions about inhaler therapy - Addictive - Very strong medicine Both physicians and patients to be made more aware

Peak flow meters