2© paradigm publishing, inc. chapter 14 the respiratory system and drug therapy

© Paradigm Publishing, Inc. 2

Chapter 14

The Respiratory System and Drug Therapy


Chapter 14

Topics

• Anatomy and Physiology of the Respiratory System• Asthma• Chronic Obstructive Pulmonary Disease (COPD)• Pneumonia and Tuberculosis (TB)• Cystic Fibrosis• Smoking Cessation• Herbal and Alternative Therapies


Anatomy and Physiology of the Respiratory System

Regions of the Respiratory Tract• The respiratory tract has an upper region and a lower

region Upper Respiratory Tract: nasal passages, sinuses, and

the throat area Epiglottis and larynx (voice box) are in the upper

throat Lower Respiratory Tract: bronchi, bronchioles, lungs,

and alveoli • Because different diseases and conditions affect each

region, different drug therapies are prescribed



Upper and Lower Respiratory Tracts• The epiglottis

divides the upper and lower respiratory tracts



The Process of Breathing• When a person breathes, air is pulled into and pushed out

of the lungs• In the lungs, small air sacs (alveoli) fill with air and allow

for gas exchange with the blood Alveoli’s large surface area and number of blood vessels

allow oxygen to move into the blood and carbon dioxide (a by-product of cellular function) to leave the blood

This process is called the gas-exchange process



The Gas-Exchange Process• Involves two actions

Oxygen is picked up in the lungs and is carried by red blood cells to all the cells of the body

Carbon dioxide is brought back to the lungs to be expelled during exhalation

• Serves two functions Provides oxygen to body cells to supply energy and to

fuel cellular respiration Helps maintain acid/base balance in blood; keeps blood

pH within safe limits



The Gas-Exchange Process (continued)


Asthma

About Asthma• Affects over 22 million people in the U.S.—6 million of

which are children—and is on the rise• Accounts for many ER visits, hospitalizations, and deaths• The primary goals of treatment

Reduce acute and chronic symptoms Prevent exacerbations Minimize hospitalizations or visits to the ER

• Other goals of treatment Improve quality of sleep Allow for increased patient activity


Asthma

About Asthma (continued)• Asthma is an inflammatory disorder of the airways in

which bronchioles constrict, mucus increases, and lung tissue swells Chronic (not curable) condition; can be reversible in

that it can improve or be controlled with medications Episodic condition: times of poor airflow and difficulty

breathing alternate with times of normal function• Symptoms: coughing, wheezing, breathlessness, and chest

tightness


Asthma

Asthmatic Lung• A lung with asthma

“overreacts” to produce excess mucus and swelling

• The combination of excess mucus and bronchoconstriction makes airflow difficult


Asthma

Asthma Attacks • Characterized by hyperreactivity of the airways • Triggers (common): smoke, dust, exercise, pet dander, cold

weather, colds, flu• Triggers (other): medicines, anxiety, laughing, some foods• Immediately after exposure to a trigger, mast cells in lung

tissue release histamine and other chemical mediators Causes bronchospasm and increased mucus production

• Drug treatment can help control airway constriction and breathing symptoms Without treatment, lung function declines


Asthma

Assessment and Treatment of Asthma• Categorized into levels of severity: intermittent, mild,

moderate, and severe Categories are based on how symptoms affect sleep,

normal daily activities, and breathing ability• Pulmonary function tests used to assess asthma severity• Rescue treatment is used once symptoms have begun• Long-term drug therapy prevents exacerbations, improves

lung function, and decreases the need for short-term relief therapies


Asthma

Monitoring of Lung Function• Patients can monitor their lung function at home with a

small, portable peak flow meter (sold in most pharmacies) It measures the strength of airflow exiting the lungs When patients chart their results daily, they can see if

their lung function is declining over time If so, they can work with their healthcare providers

• Technicians can suggest that patients using multiple inhalers for asthma also use a peak flow meter regularly Pharmacists can offer instruction for proper use


Asthma

Drugs for Asthma• Asthma management generally begins with inhalers and

proceeds to oral therapies• Short-term drug therapy

Rescue inhalers for quick relief during an asthma attack Short-acting beta agonists (with or without an inhaled

corticosteroid) • Long-term drug therapy

Inhaled corticosteroids as anti-inflammatory agents Leukotriene inhibitors or mast cell inhibitors to improve

bronchoconstriction


Asthma

Drugs for Asthma: Methods of Drug Delivery• MDI

Used most often to deliver beta agonist agents and inhaled corticosteroids

Used with a spacer that improves drug delivery Spacer briefly suspends medication mist in the air

• Dry powder inhaler Contains dry powder that is inhaled into the lungs

• Nebulizer machine Creates a fine mist that is inhaled through a mask


Asthma

Drugs for Asthma: Short-Acting Beta Agonists• Indications (inhalation): short-term relief of breathing

symptoms related to asthma; sometimes used for COPD• Mechanism of Action: stimulate beta-2 receptors in lungs

and produce smooth muscle relaxation in bronchioles• Side Effects (common): dizziness, nervousness, heartburn,

nausea, tremors• Side Effects (other): increased BP, heart palpitations• Cautions: interact with digoxin and can cause toxicity;

should not be used with beta blockers• Caution: Shake MDIs before each use


Asthma

Drugs for Asthma: Inhaled Corticosteroids• Indication (inhalation): long-term treatment and control of

moderate to severe asthma; sometimes used for COPD Purpose: prevent frequent asthma attacks

• Indication (oral): short-term therapy only• Mechanism of Action: decrease inflammation causing

bronchoconstriction and excess mucus production• Side Effects (common): dry mouth, headache, sore throat,

hoarseness, coughing, oral fungal infection (oral thrush)• Cautions: shake MDIs before each use;

do not shake dry powder inhalers before use


Asthma

Drugs for Asthma: Leukotriene Inhibitors• Indications (inhalation): long-term control of moderate to

severe asthma; allergic rhinitis Often prescribed when short-acting beta agonists and

inhaled corticosteroids are not controlling symptoms May be limited to specific ages of children

• Mechanism of Action: zileuton inhibits leukotriene synthesis; zafirlukast and montelukast are leukotriene receptor blockers

• Side Effects (common): nausea, sore throat, sinusitis• Caution: contraindicated in patients with liver problems


Chronic Obstructive Pulmonary Disease (COPD)

About COPD• Fourth leading cause of chronic disease and death

in U.S.; most people with COPD are smokers• Chronic and progressive disease that is not reversible;

airflow is limited by an abnormal inflammatory response• Two sets of symptoms: chronic bronchitis and emphysema

Chronic bronchitis: a persistent cough producing sputum for 3+ months for at least 2 consecutive years

Emphysema: fast, labored breathing that results from damaged or destroyed alveolar walls

Impaired walls reduce lung surface area



Drugs for COPD • Drug therapy

Relieves symptoms Improves quality of life Allows increased patient activity

• Indications (most agents): bronchoconstriction that occurs as the condition gets worse

• Indication (portable oxygen): most severe states of COPD Technicians do not typically dispense oxygen



Drugs for COPD: Anticholinergics • Indication: first-line treatment for bronchoconstriction• Mechanism of Action: inhibit ACh (neurotransmitter that

causes smooth muscles in the lungs to constrict)• Routes: all are inhalation; ipratropium is also intranasal• Side Effects (common): dry mouth, nervousness, dizziness,

headache, cough, nausea, nasal dryness, upper RTI• Cautions: contraindicated in patients with glaucoma,

urination problems, or soy or peanut allergies• Cautions: ipratropium inhalers need primed before first

use; tiotropium capsules are inhaled (not swallowed)


Your Turn

Question 1: At times, a patient has chest tightness and wheezes and coughs. He is diagnosed with asthma. What drug therapy is likely to be prescribed?

Answer: Asthma management generally begins with inhalers. Typically, short-acting beta agonists (with or without an inhaled corticosteroid) are the first treatment.

Question 2: What is a restriction of anticholinergics, the first-line treatment for bronchoconstriction from COPD?

Answer: Patients should not take these agents if they are allergic to peanuts or soy or have glaucoma or urination problems.



Drugs for COPD: Long-Acting Beta Agonists• Indications: COPD; also severe asthma• Mechanism of Action: stimulate beta-2 receptors in lungs

and produce smooth muscle relaxation in bronchioles administered less often than short-acting beta agonists

• Route: all are inhalation• Side Effects (common): dizziness, heartburn, nausea,

tremors• Side Effects (severe): increased BP, heart palpitations• Caution: do not use with digoxin or beta blockers• Caution: shake MDIs before each use


Pneumonia and Tuberculosis (TB)

About Pneumonia• A lower RTI caused by bacterial, viral, or fungal pathogens• Two types of pneumonia: CAP and nosocomial

CAP: acquired from exposure outside of an inpatient facility

Nosocomial pneumonia: acquired while hospitalized or living in a long-term care facility

Severe and difficult to treat because it is usually caused by more virulent pathogens



About Tuberculosis• An infectious disease caused by a mycobacterium that

infects the lungs• It causes tubercles to form in the lungs; difficult to kill• Incidence is on the rise due to drug-resistant strains and

more prevalent immunodeficiency conditions • Annual PPD skin test for TB exposure required for

healthcare workers in inpatient or long-term care settings For PPD skin test, an injection is placed just under the

skin, then checked 48–72 hours later for inflammation and swelling



About Tuberculosis (continued)• For positive PPD test, chest x-ray and other tests are done

to determine if drug therapy is needed Not everyone exposed to TB develops the full disease

with active organisms• Symptoms (active disease): night sweats, weight loss,

coughing blood, chest pain, fatigue• Universal Precautions: put on gown, mask, and gloves

before entering the room of a patient with TB Remove these items on exiting to protect against

transmission



Drugs for Pneumonia • A two-step treatment process is usually followed, because

determining the disease type takes time• First process: an antibiotic covering a broad range of

pathogens is started• Second process (narrowing treatment): lab tests and

cultures are taken to determine the bacteria or fungus Technicians may retrieve these results

• Once the pathogen is found, drug therapy may change Bronchodilators and corticosteroids may be

administered to assist labored breathing



Drugs for TB• Drugs for TB are often specialized; not dispensed regularly

(see Table 14.6) • Reemergence of TB due to the high rate of nonadherence

to drug therapy Course of therapy for TB is 6 months or longer Many unpleasant side effects of TB therapy Doses are not always taken on an empty stomach or on

a consistent basis• Incomplete therapy promotes the emergence of drug-

resistant TB


Cystic Fibrosis

About CF• A genetic disease that affects exocrine glands and their

ability to transport chloride across cell membranes• Thick, sticky mucus is produced in the lungs, GI system,

and pancreas; this mucus causes many problems Sweat glands and reproductive organs also affected

• Treatment needed for nutrition, pancreas, and respiratory complications

• Most hospitalizations and deaths due to pulmonary problems Most patients die before early to middle adulthood


Cystic Fibrosis

Drugs for CF• Specialized drugs; not dispensed regularly in all settings• Respiratory therapy includes percussion (non-drug

treatment), mucolytics, and antibiotics Percussion is a tapping, pounding movement

performed on the back and chest Breaks up and helps expectorate mucus from lungs

• Nebulizer therapy with bronchodilators, hypertonic saline, acetylcysteine accompanies use of percussion

• Antibiotics and antifungal drugs are used to combat the bacteria and fungus in respiratory mucus secretions


Cystic Fibrosis

Drugs for CF (continued)• Special vitamins and pancreatic enzyme supplements are

used to help prevent ductal obstructions and steatorrhea Improve growth and life expectancy for children

with CF• Pancreatic enzyme supplements all contain varying

amounts of lipase, protease, and amylase• Fat-soluble vitamins are poorly absorbed

Supplements containing vitamins A, D, E, and K are often prescribed


Smoking Cessation

About Cigarettes and Nicotine• Cigarette smoking is the leading cause

of preventable death in the U.S.• It contributes to heart disease, COPD, stroke, and many

malignancies in addition to lung cancer• Nicotine in cigarettes is addictive, so smoking can be

difficult to quit• Withdrawal from nicotine includes many symptoms


Smoking Cessation

Symptoms of Nicotine Withdrawal

• Anxiety• Decreased blood pressure and heart rate• Depression• Drowsiness• Headache• Increased appetite and weight gain• Insomnia• Irritability, frustration, and restlessness


Smoking Cessation

Drugs for Smoking Cessation• Prescription and OTC medications

Can reduce nicotine withdrawal symptoms Can help patients successfully quit if combined with

smoking cessation programs and social support• Drug therapy for smoking cessation includes nicotine

supplements, antidepressants, or a nicotine blocker• Nicotine supplements

Available in inhaler, patch, spray, and gum forms Reduce absorbed nicotine slowly, which lessens

withdrawal symptoms


Smoking Cessation

Drugs for Smoking Cessation (continued)• Antidepressants: Bupropion

Available in oral dosage form; prescription only Combats emotional instability of withdrawal Reduces nicotine cravings

• Nicotine Blocker: Varenicline Available in oral dosage form; prescription only Blocks nicotine from binding to pleasure receptors Reduces withdrawal symptoms and weight gain Is most effective when accompanying a formal smoking

cessation program


Smoking Cessation

Drugs for Smoking Cessation (continued)• Side Effects (nicotine products): abdominal pain,

confusion, diarrhea, dizziness, headache, hearing loss, nausea, sweating, vision changes, vomiting, weakness

• Side Effects (bupropion): drowsiness, dizziness, blurred vision, insomnia; avoid taking with alcohol

• Side Effects (varenicline): nausea, unusual dreams; take with food and full glass of water

• Cautions (bupropion, varenicline): depression, suicidal thoughts; boxed-in warning label alerts

• Caution (bupropion): do not stop using abruptly


Your Turn

Question 1: A nurse is celebrating her first year of working in a long-term care facility. How can she tell if has been exposed to tuberculosis during that time?

Answer: She will get an annual PPD skin test. In this test, an injection is placed just under the skin and then checked 48–72 hours later. She will test positive if she has inflammation and swelling at the injection site.

Question 2: What is the function of nicotine supplements that are used for smoking cessation?

Answer: They are used to reduce absorbed nicotine slowly over time which helps to reduce many withdrawal symptoms.


Herbal and Alternative Therapies

• Echinacea, zinc, and vitamin C are herbal and supplement products that boost immune function Products fight off cold and flu viruses that can progress

to pneumonia Standardized regimens have not been proven Little is known about their effects on lower RTIs such as

pneumonia• Echinacea or zinc are taken at the first sign of infection• Vitamin C is taken as a preventive agent during cold and

flu season


Summary• Inhaled therapies for asthma and COPD are delivered via

MDIs, dry powder inhalers, and nebulizer machines• Short-acting beta agonists are used for acute asthma relief• Inhaled corticosteroids are long-term asthma treatment• Anticholinergics are first-line, long-term COPD treatment• Antibiotics are the initial treatment for pneumonia• TB agents must be taken over six months• Long-term smoking cessation success is more likely if drug

therapy is combined with cessation programs

2© paradigm publishing, inc. chapter 14 the respiratory system and drug therapy

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respiratory system regions

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airflow difficult slide

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