39
Asthma

1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Embed Size (px)

Citation preview

Page 1: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

1

Asthma

Page 2: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

2

Page 3: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

3

References• Pharmacotherapy: A Pathophysiologic Approach –

Chapter 33 (8th ed)• Pharmacotherapy: Principles and Practice –

Chapter 14 (3nd ed)• Applied Therapeutics: The Clinical Use of Drugs –

Chapter 22• Global Initiative for Asthma (GINA) 2012.

Available from: http://www.ginasthma.org• The National Asthma Education and Prevention

Program (NAEPP): Expert Panel Report 3, Guidelines for the Diagnosis and Management of Asthma -- Full Report 2007

Page 4: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

7

• Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role mast cells, eosinophils, T lymphocytes and epithelial cells.

• Chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning

• These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment

• Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role mast cells, eosinophils, T lymphocytes and epithelial cells.

• Chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning

• These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment

Definition of Asthma

Page 5: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

8

تعريف•مرض • هو الوزي الربو يشبه مسموع تنفسي صوت المصوت الشديد النفس ضيق من متقطعة هجمات بحدوث يتميز التنفسي الجهاز بالمعالجة زفي أو تلقائي بشكل الهجمة تزول ثم ومتعددة مختلفة لمنبهات قصبي تحسس فرط وجود مع

Page 6: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

9

PATIENT PRESENTATION• Chief Complaint"I am failing my pharmacotherapy class. I have missed so

much time because of my asthma."

• HPI (history of present illness) K is a 65 yo female who presents to the health service

physician complaining of increased shortness of breath, wheezing, poor exercise tolerance, and cold started 4 days ago. At that time, she began monitoring her peak flow rates twice daily and implemented an action plan that included frequent albuterol nebulizations.

Her peak flows for the past 4 days have ranged from 190 to 250 L/min and usually have been at the lower end of that range in the morning.

Page 7: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

10

• PMH (past medical history)

Moderate persistent asthma for 12 years; she has been hospitalized twice in the past 2 years for asthma exacerbations and has been to the ED 4 times in the past 9 months

Perennial allergic rhinitis

Hypertension, CAD, Heart failure stage B, her blood pressure is 135/85. her CAD is controlled (class1)

Page 8: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

11

• Meds-Ventoline HFA MD1 2puffs BID-Beclfotre 250 MDI 1 puff QD- Beconase Inhalation Aerosol (nasal) 1 spray each

nostril TID - Serevent MDI 1 puffs QD- Atenolol and captopril for Hypertension- Prednisolone 50 mg HS

• Compliance with above regimen is variable; she refills her Serevent regularly on schedule, but is typically a few weeks late on the steroid nasal and oral inhaler; patient obtains a Ventoline HFA MDI approximately every 2 weeks. She frequently misses her dose of the steroid medications and experiences discomfort from the nasal spray.

Page 9: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

12

• ROS (Review of Symptoms)

Unremarkable except for nasal stuffiness and heartburn (possible GERD)

Patient also reports that she wakes up at least twice a week with shortness of breath and wheezing, and occasionally feels chest tightness in the morning (before the acute asthma attack)

Page 10: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

13

• Physical examination-GenAnxious-appearing white woman in apparent

distress with audible wheezing, unable to speak in complete sentences because of dyspnea

-VSBP 148/88, P 105, RR 28, T 38.2°C; Wt 58 kg-CVTachycardia

Page 11: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

14

• Assessment• 20 yo woman with moderate to severe

exacerbation of asthma precipitated by viral upper respiratory infection

Page 12: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

15

Pharmaceutical Care

Q1 Find out what are the reasons for exacerbations• Check indication• Check appropriateness of treatment• Check dosage regimen• Check interactions • Check ADR• Check knowledge• Check Adherence• Write down your recommendations

Page 13: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

21

Etiology• Asthma is a partially heritable complex syndrome that results from a complex interaction of

genetic and environmental factors.– Genetic predisposition (predispose individuals to, or protect them from, developing asthma)

• Atopy (genetically determined state of hypersensitivity to environmental allergens, manifested as the presence of positive skin-prick tests or the clinical response to common environmental allergens = genetically mediated predisposition to an excessive IgE reaction)

• linked with metalloproteinase genes (ADAM33)– Environmental exposure (influence susceptibility to development of asthma in predisposed

individuals, precipitate asthma exacerbations, and/or cause symptoms to persist)• risk factors

– socioeconomic status– family size– tobacco smoke (Maternal smoking during pregnancy or exposure to secondhand

smoke after birth increases the risk of childhood asthma)– allergen exposure (tree and grass pollen, house dust mites, household pets, molds)– urbanization– decreased exposure to common childhood infectious agents

• hygiene hypothesis (homework)

Page 14: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

The "hygiene hypothesis"is being used to explain the increase of asthma in Western

countries.It proposes that genetically susceptible individuals develop

allergies and asthma by allowing the allergic immunologic system (T-helper cell type 2 [TH2]-lymphocytes) to develop instead of the immunologic system used to fight infections (T-helper cell type 1 [TH1]-lymphocytes),

The first 2 years of life appear to be most important for the exposures to produce an alteration in the immune response system.

Support for the hygiene hypothesis for asthma comes from studies demonstrating a lower risk for asthma in children who live on farms and are exposed to high levels of bacteria, in those with a large number of siblings, in those with early enrollment into child care, in those with exposure to cats and dogs early in life, or in those with exposure to fewer antibiotics.

Page 15: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3
Page 16: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

28

MECHANISMS OF ASTHMA• The current concept of asthma pathogenesis is that a

characteristic chronic inflammatory process involving the airway wall causes the development of airflow limitation (bronchospasm, edema, hypersecreation) and increased airway responsiveness, the latter of which predisposes the airways to narrow in response to a variety of stimuli.

• Characteristic features of the airway inflammation are increased numbers of activated eosinophils, mast cells, macrophages, and T lymphocytes in the airway mucosa and lumen.

• In parallel with the chronic inflammatory process, injury of thebronchial epithelium stimulates processes of repair thatresult in structural and functional changes referred to as“remodeling”.

Page 17: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

29

Airway remodeling refers to structural changes, including an alteration in the amount and composition of the extracellular matrix in the airway wall leading to airflow obstruction that eventually may become only partially reversible

Page 18: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

34

Asthma: Pathological changes

Page 19: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

38

Diagnosis of asthma

Consider the diagnosis of asthma in patients with

some or all of these features

Symptoms (episodic/variable)• wheeze• shortness of breath• chest tightness• cough

Page 20: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

39

Diagnosis of asthma Symptoms (episodic/variable)• wheeze• shortness of breath• chest tightness• cough

Signs• none (common)• wheeze –expiratory (

inspiratory)• Tachypnea

Consider the diagnosis of asthma in patients with

some or all of these features

Page 21: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

41

Diagnosis of asthma

Objective measurements• >20% diurnal variation on 3 days in

a week for 2 weeks on PEF diary• or FEV1 12% (and 200ml) increase after

short acting ß2 agonist or steroid tablets

• or FEV1 12% decrease after 6 minutes of

running exercise• histamine or methacholine challenge in

difficult cases

Symptoms (episodic/variable)• wheeze• shortness of breath• chest tightness• cough

Signs• none (common)• wheeze – diffuse, bilateral,

expiratory ( inspiratory)• tachypnea

Helpful additional information• personal/family history of asthma or atopy • history of worsening after aspirin/NSAID,

blocker use• recognised triggers – pollens, dust, animals,

exercise, viral infections, chemicals, irritants• pattern and severity of symptoms and

exacerbations

Consider the diagnosis of asthma in patients with

some or all of these features

Page 22: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

42

Spirometry َن�ُّف�س ق�الَّت ياُس!

• Spirometry is preferred for diagnostic testing, and should be used for both diagnosis and assessment of progress.

• The aim of spirometry in general practice is to assess variability of airflow obstruction, and to measure the degree of airflow obstruction compared to predicted normal.

Page 23: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Spirometry (Homework) Lung volumes often are measured to obtain

information about the size of the patient's lungs, because pulmonary diseases can affect the volume of air that can be inhaled and exhaled.

The tidal volume is the volume of air inspired or expired during normal breathing.

The volume of air blown off after maximal inspiration to full expiration is defined as the vital capacity (VC).

The residual volume (RV) is the volume of air left in the lung after maximal expiration.

The volume of air left after a normal expiration is the functional residual capacity (FRC).

Total lung capacity (TLC) is the VC plus the RV.

Patients with obstructive lung disease have difficulty with expiration; therefore, they tend to have a decreased VC, an increased RV, and a normal TLC.

Classic restrictive lung diseases (e.g., sarcoidosis, idiopathic pulmonary fibrosis) present with decrements in all lung volumes.

Patients also may have mixed lesion diseases, in which case the classic findings are not apparent until the disease has advanced considerably.

The spirometer also can be used to evaluate the performance of the patient's lungs, thorax, and respiratory muscles in moving air into and out of the lungs. Forced expiratory maneuvers amplify the ventilation abnormalities produced.

Page 24: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

44

Page 25: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

45

45

Page 26: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

47

Page 27: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Peak Expiratory Flow

The PEF is the maximal flow that can be produced during the forced expiration.

The PEF can be measured easily with various handheld peak flow meters and commonly is used in emergency departments (EDs) and clinics to quickly and objectively assess the effectiveness of bronchodilators in the treatment of acute asthma attacks. Peak flow meters also can be used at home by patients with asthma to assess chronic therapy.

PEF measurements are ideally compared to the patient’s own previous best measurements using his/her own peak flow meter.

The changes in PEF generally parallel those of the FEV1; however, the PEF is a

less reproducible measure than the FEV1.

A healthy, average-sized young adult male typically has a PEF of 550 to 700 L/minute.

Peak expiratory flow (PEF) measurements can be an important aid in both diagnosis and monitoring of asthma. HOW?

Page 28: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

53

Classification of Severity

Page 29: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Factors Affecting Asthma Severity Major factors that may contribute to the severity of asthma include:

allergens typically associated with atopy; chemical exposures in occupational environments; exposure to: tobacco smoke, irritants, and indoor and outdoor pollution.

Other factors include:Rhinitis: intranasal corticosteroids may improve asthma symptoms Acute and chronic sinusitis: antibiotic therapy of sinusitis may improve

asthma symptoms.Nasal polyps are associated with aspirin-sensitive asthma: should be

counseled against using NSAIDs.Gastroesophageal reflux, especially nighttime symptoms.Non-selective β-blockers, including those in ophthalmic preparations, may

cause asthma symptoms: these agents used based on benefit risk assessment.

The ingestion of sulfites can also worsen asthma. These agents are often found in processed potatoes, shrimp, dried foods, beer, and wines.

Viral infections are the most common cause of increased asthma symptoms and asthma exacerbations.

Page 30: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

64

New Guideline :Classification of asthma by severity is usefulwhen decisions are being made about management at the

initial assessment of a patient.

Page 31: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

65

Page 32: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

66

Page 33: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Aerosol Therapy of Asthma

DevicesFactors Determining Lung Disposition of Aerosols (Device and Patients Determinants)Patient Education

Page 34: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

DevicesInhaled medications are preferred (WHY?)

Inhaled medications for asthma are available as: Metered-dose inhaler (MDI)

pressurized metered-dose inhalers (pMDIs), breath-actuated MDIs,

Dry-powder inhaler (DPI)Nebulizers

jet (mechanically produces a mist of drug)ultrasonic (uses sound waves to generate the aerosol)

Spacer (or valved holding-chamber) devices make inhalers easier to use and reduce systemic absorption and side effects of inhaled glucocorticosteroids.

Must determine which device is best for each patient

Page 35: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

An MDI consists of an aerosol canister and an actuation device (valve). The drug in the canister is a suspension or solution mixed with propellant. The valve controls the delivery of drug and allows the precise release of a premeasured amount of the product

A nebulizer is a device that turns asthma medication into a fine mist that's breathed in through a mouthpiece or mask worn over the nose and mouth. A nebulizer is generally reserved for people who can't use an inhaler, such as infants, young children, people who are very ill or people who need larger doses of medication.

Page 36: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3
Page 37: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Patient EducationAppropriate inhalation technique is vital for optimal drug

delivery and therapeutic effectup to 30% cannot master MDI technique

Rinse mouth after inhaled corticosteroids (ICS)< 4 years old usually need to attach a face mask to the

inhalation device

For instructions for inhaler and spacer usehttp://

www.ginasthma.org/other-resources-instructions-for-inhaler-and-spacer-use.html

For educational videos on the use of inhalers , visit http://www.nationalasthma.org.au http://www.mayoclinic.com/health/asthma/DS00021&tab=multimedia

Page 38: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3

Take off the cap and shake the inhaler hard

Breathe out all the way

Hold the inhaler 1 to 2 inches in front of your mouth.

Start breathing in slowly through your mouth, and then press down on the inhaler one time. Breathe in slowly, as deeply as you can. Slowly count to 10 while you hold your breath.

Rinse your mouth afterward to help reduce unwanted side effects.

Page 39: 1 Asthma. 2 3 References Pharmacotherapy: A Pathophysiologic Approach – Chapter 33 (8 th ed) Pharmacotherapy: Principles and Practice – Chapter 14 (3