INHALATION THERAPY IN ASTHMA AND COPD

Dr Muhammed Aslam

Junior Resident

MD Respiratory Medicine

Academy Of Medical Science

Pariyaram , Kanuur

Inhalation delivery systems• Bronchodilator aerosol for asthma -1935• Conventional pressurized MDI - 1956

Types

• Pressurized metered dose inhaler (pMDI)

• MDI with spacers or holding chambers

• Breath actuated MDI• Dry powder inhaler (DPI)• Nebulizers

Pressurized MDI

Propellants Provides the force to generate the aerosol cloud and is also the

medium in which the active component must be suspended or dissolved. Propellants in MDIs typically make up more than 99% of the delivered dose

• Chlorofluorocarbons (CFCs) most commonly used propellants were the

chlorofluorocarbons CFC-11, CFC-12 and CFC-114.

Banned due to adverse effect on ozone layer

• hydrofluoroalkanes (HFA) HFA 134a (1,1,1,2,-tetrafluoroethane)

These new devices are more effective. The HFA propellant produces an aerosol with smaller particle size, resulting in improved deposition in the small airways and greater efficacy at equivalent doses compared with CFC MDIs.

• When the valve is actuated propellant and drug leave the inhaler at high velocity

• Majority of drug impacts in oropharynx

• Less than 25% reaches the lung

• Shake the canister • Place the mouthpiece of actuator between

the lips• Breathe out steadily• Release the dose while taking a slow

deep breath in• Hold the breath in while counting to 10

Most efficient way of using MDI- steps

Advantages of MDIs

• Compact, portable ,convenient• Multidose delivery capability• Lower risk of bacterial contamination• Suitable for emergency situation

Disadvantages of MDIs

• Needs correct actuation and inhalation coordination- difficult for children and elderly patients

• Cold freon effect• High pharyngeal drug deposition• Flammability possibility of new HFA

propellants• Remaining dose –difficult to determine

MDI with Spacer

Steps for Using a Spacer with an MDI

• Insert the inhaler/canister into spacer and shake.

• Breathe out.• Put the spacer mouthpiece into your

mouth.• Press down on the inhaler once.• Breathe in slowly (for 3-5 seconds).• Hold breath for 10 seconds.

Advantages of MDI with spacer• Compensate for poor technique/coordination

with MDI• Spacers slow down the speed of the aerosol

coming from the inhaler, meaning that less of drug impacts on the back of the mouth and somewhat more may get into the lungs. Because of this, less medication is needed for an effective dose to reach the lungs, and there are fewer side effects from corticosteroid residue in the mouth.

Disadvantages• Large size and volume of device• Bacterial contamination is

possible; device needs to be cleaned periodically

• Electrostatic charges may reduce drug delivery to the lungs

Breath actuated MDI

LATEST IN MDI

Dry powder inhaler (DPI)

Single dose DevicesHad to be reloaded with capsule containing micronized drug in a large particle carrier powder ,usually lactose

Multiple DoseDevices

Advantages• Breath-actuated• Less patient coordination required• Spacer not necessary• Compact Portable• No propellant• Usually higher lung deposition

than a pMDI

Disadvantages of DPI• Work poorly if inhalation is not forceful enough• Many patients cannot use them correctly (e.g.

capsule handling problems for elderly• Most types are moisture sensitive

Humidity potentially causes powder clumping and reduced dispersal of fine particle mass

• Need to reload capsule each time

Nebulizers

Jet nebulizer Ultrasonic nebulizer

Pneumatic Jet Nebulizer

• Delivers compressed gas through a jet, causing an area of negative pressure and drawing the liquid up the tube by the Bernoulli effect. The solution is entrained into the gas stream and then sheared into a liquid film that is unstable and is broken into droplets by surface tension forces. The fundamental concept of nebulizer performance is the conversion of the medication solution into droplets in the respirable range of 1-5 micrometers

Ultrasonic Nebulizer• Generates high-frequency ultrasonic waves

(1.63 MHz) from electrical energy via a piezoelectric element in the transducer. These ultrasonic waves are transmitted to the surface of the solution to create an aerosol. Aerosol delivery is by a fan or the patient’s inspiratory flow; particle sizes may be larger with this device. A limitation of ultrasonic nebulizers is that they do not nebulize suspensions efficiently

Advantages Of Nebulizers• Provide therapy for patients who cannot

use other inhalation modalities (eg, MDI, DPI)

• Allow administration of large doses of medicine

• Patient coordination not required• Effective with tidal breathing• Dose modification possible• Can be used with supplemental oxygen

Disadvantages Of Nebulizers

• Decreased portability• Longer set-up and

administration time• Higher cost• Electrical power source

required• Contamination possible

Drugs used in inhaler therapy

For Asthma

Taken from

The Global Initiative for Asthma (GINA)  2011 guidelines

Inhaler Therapy• CONTROLLERS Inhaled glucocorticoids ,Long acting

inhaled beta 2 agonists,Cromones,

• RELIEVERS Short acting beta 2 agonists,

Anticholinergics

Inhaled Glucocorticosteroids• Most effective anti inflammatory

medication for the treatment of persistent asthma

• Reduces asthma symptoms• Improves quality of life• Decrease Airway hyper responsiveness• Improve lung function• Control airway inflammation• Decrease frequency and severity of

exacerbations• Decrease mortality

Inhaled Glucocorticosteroids• Beclomethasone dipropionate• Budesonide• Ciclesonide• Flunisolide• Fluticasone propionate• Mometasone furoate• Triamsinalone acetonide

• Most of the benefit – dose equivalent of 400 microgram budesonide per day

• Increasing dose – Little benefit & more side effect

• Add-on therapy with another class controller is preferred over increasing dose of steroids

• Tobacco smoking decreases responsiveness to inhaled glucocorticoids

Local Side effects

• Oropharyngeal candidiasis• Dysphonia• Cough (upper airway irritation)

• s/e reduced by –spacer,mouth washing, prodrug(ciclesonide,beclomethasone)

Systemic side effect• Depends on dose , potency, delivery

system, systemic bio availability ,half life, first pass metabolism, treatment duration

• Easy bruising, adrenal suppression, decreased bone mineral density ,cataract, glaucoma

Long acting inhaled beta2 agonists

• Salmeterol and formoterol

• Not as monotherapy

• Most effective when combined with inhaled glucocorticoids

Advantages of combination therapy

• Improve symptoms scores• Decreases nocturnal asthma symptoms• Improve lung functions• Decreases use of rapid acting inhaled b2

agonists• Reduces no: of exacerbation• Rapid control• Reduces dose of inhaled glucocorticoids

• Salmeterol and Formoterol has similar duration of action , but formoterol has more rapid onset

• Formoterol Budesonide combination can be given for both rescue and maintenance

Side effects• Less than oral treatment• Cvs stimulation , skeletal muscle

tremor• Hypokalemia• Refractoriness to beta 2 agonists

Cromones• Sodium cromo Glycate , Nedocromil

sodium• Limited role• Mild persistent asthma and exercise

induced bronchospasm• Less effective than low dose inhaled

glucocorticoids• s/e – cough, sore throat , unpleasant taste

Reliever medications• Short acting beta 2 agonists • Anti cholinergic

Rapid acting inhaled beta 2 agonist• Salbutamol , terbutaline, fenoterol,

levalbuterol,reproterol,pirbuterol

• Medication of choice for relief of bronchospasm during acute exacerbation of asthma and pre treatment of exercise induced broncho constriction

• Should be used only on an as needed basis at lowest dose and frequency

• s/e – tremor, tachycardia

Anti cholinergic broncho dilators• Ipratropium bromide, oxitropium

bromide• Less effective than beta 2 agonists• Combination with b2 agonist-

significant improvement

• S/e dryness, bitter taste

In children

In children

Inhaler Therapy For COPDTaken from Global Initiative for Chronic Obstructive Lung Disease (GOLD) Guidelines 2011

Beta2 Agonists• Effect of short acting b2 agonist- 4to 6 hrs• Improves FEV1 and symptoms

• Long acting beta2 agonist -12 hr or more• Formoterol and salmeterol improves FEV1 ,lung

volumes,dyspnoea,health related quality of life,exacerbation rates

• Indacaterol – duration of action 24hrs

Anti cholinergic• Ipratopium bromide , oxitropium bromide,

tiotropium bromide

• Broncho dilator action last longer than SABA- upto 8 hrs

• Tiotropium – >24 hrs

Inhaled corticosteroids• Long term treatment with inhaled CS

improves symptom , lung function ,quality of life, and reduces frequency of exacerbations in COPD patients with FEV1 < 60%

• Does not decline the long term decline of FEV1 nor mortality

Combination Therapy• Inhaled Coticosteroid with Long

Acting B2 Agonist is more effective

• A triple therapy by adding tiotropium may furthur improves

Oxygen therapy

Conclusion• A number of inhalation devices are

available for the treatment of pulmonary diseases, each with its own advantages and disadvantages. None has proven to be superior to the others in any of the clinical situations tested. Whichever device is chosen, the key to successful treatment lies at a proper inhaler technique

Thank you !!