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Chapter 20
Drugs Affecting the
Respiratory System
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Asthma and Chronic
Obstructive Pulmonary
Disease (COPD)
• Asthma—chronic disease with
abnormal reactivity of the bronchioles
to triggers such as pollen, exercise,
dust mites, and cigarette smoke
• COPD—chronic bronchitis and
emphysema result in loss of elasticity
of lungs and airway constriction
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Bronchodilators
• Selective β2-agonists
– Provide symptomatic relief of wheezing
and chest tightness
– Do no prevent asthma attacks
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Actions and Indications
• Selective β2-agonists selectively relax
smooth muscle surrounding bronchioles.
• Albuterol is fast-acting treatment of
choice for symptoms of asthma
occurring once or twice a week.
• For persistent asthma, maintenance
treatment with long-acting β2-agonists,
such as formoterol and salmeterol, can
sometimes be beneficial.
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Actions and Indications
(cont’d)
• COPD treatment includes
bronchodilators with beta-agonists and
anticholinergic bronchodilators
(ipratropium and tiotropium).
• Actions include bronchodilation, relief
of symptoms, and improved quality of
life on a temporary basis.
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Administration
• Systemic circulation via mouth or
injection
• Direct local administration via
inhalation, when possible, is preferred
route due to direct delivery to airways,
less systemic absorption, and fewer
systemic side effects.
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Administration (cont’d)
• Metered dose inhaler (MDI)—small
pressurized canister containing drug
and mouthpiece for administration of
set dose of drug at each activation
• Nebulizer—device uses small
compression pump to convert drug
solution into a mist inhaled through a
mouthpiece
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Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
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Side Effects
• Selective β2 in repeated use or high
doses can have deleterious cardiac
effects such as fatal arrhythmias;
jitteriness and increased heart rates
are fairly common.
• Beta-agonists can produce adverse
CNS effects including anxiety, fear,
tension headache, and tremor.
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Side Effects (cont’d)
• Dry mouth is common with ipratropium
and tiotropium.
• Tiotropium occasionally causes urinary
retention and constipation.
• Dry powder inhaler use is associated
with throat irritation and coughing.
• Use of a spacer with MDI can reduce
associated bad taste and irritation.
Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins
Tips for the Technician
• Become familiar with respiratory drug
delivery systems and equipment to
provide customers with sound
information.
• Encourage inexperienced patients to
look over inhaler instructions while still
in the pharmacy.
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Review
The device that uses a small compressor pump for aid
in the inhalation process is known as a:
A) MDI
B) Nebulizer
C) Mister
D) Spacer
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Answer
B) Nebulizer
A nebulizer uses a small compressor
pump to convert the drug solution into
a mist that the patient inhales through
a mouthpiece.
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Respiratory
Corticosteroids
• Glucocorticoids are endogenous
hormones synthesized from cholesterol
by the adrenal glands.
• In humans, the most important of
these hormones is cortisol.
• Synthetic derivatives of cortisol are
used for their anti-inflammatory effects
in a variety of diseases.
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Inhaled Corticosteroid
Actions and Indications
• Indicated for prevention of acute
exacerbation of asthma
• Inhibit many of the cells involved with
inflammation in the bronchi and
bronchioles and reduce airway edema
• Peak effects take several weeks;
therefore, not effective for acute
asthma attacks
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Actions and Indications
(cont’d)
• As nasal spray, corticosteroids are also
effective for allergic rhinitis, reducing
congestion and itching within a few
hours to days.
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Administration
• Intravenous
• Oral
• Inhalation
• Nasal spray
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Side Effects
• Serious side effects are much less
likely and less severe when
medications are inhaled.
• Long-term use of inhaled
corticosteroids at maximal doses can
cause minor suppression of cortisol
production in the body.
• Oral candidiasis
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Tips for the Technician
• Use special caution when dispensing
inhalers available in different strengths.
• Apply “shake well” label to MDIs.
• Dry powder inhaler devices are not
shaken before use.
• Apply auxiliary labels to include MDI
use, rinse mouth after using, and
cleaning mouthpiece after every use.
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Review
Dry powder inhalers should be shaken well to activate
before administering.
A) True
B) False
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Answer
B) False
Dry powder inhaler devices are not
shaken before use.
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Alternative Pulmonary
Anti-Inflammatory Drugs
• The mast cell stabilizers cromolyn and
nedocromil are first-line drugs for longterm prevention of asthma in place of
steroids or in addition to the regimen.
• The leukotriene modifiers montelukast,
zafirlukast, and zileuton allow reduction
of doses of inhaled corticosteroids in
some patients with chronic asthma.
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Actions and Indications
• Cromolyn and nedocromil inhibit
release of histamine, leukotrienes, and
other inflammatory chemicals by mast
cells and other granulocytes.
• Mast cell stabilizers are indicated for
long-term management of asthma.
• Cromolyn is indicated for treatment of
allergic rhinitis and has been used offlabel for chronic urticaria (hives).
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Administration
• Cromolyn and nedocromil are
administered via inhalation for asthma.
• Cromolyn is available in MDI and
nebulizer as well as nasal spray for
allergic rhinitis.
• Nedocromil is available as MDI only.
• Leukotriene inhibitors are administered
orally.
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Side Effects
• Mast cell stabilizer side effects
– Throat irritation, cough, dry mouth, and
unpleasant taste in the mouth
– Not absorbed from the respiratory tract;
there are no systemic side effects
attributable
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Side Effects (cont’d)
• Leukotriene inhibitor side effects
– Headache
– GI upset
– Hepatotoxicity, eosinophilia, and pain in
rare instances
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Tips for the Technician
• Label MDIs with auxiliary “shake well”
label.
• Label zafirlukast to be taken on empty
stomach.
• Instruct patients to take medication as
ordered, even when symptom free.
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Methylxanthine
Derivatives
• Coffee, tea, and chocolate all contain
methylxanthine derivates known to
possess bronchodilatory effects.
• Theophylline and the related drug
aminophylline are the methylxanthine
derivatives most often used for COPD
and sometimes asthma.
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Actions and Indications
• Bronchodilator and minimal antiinflammatory effects in airways
• Indicated for treatment of COPD, after
use of anticholinergic and beta-agonist
drugs
• Indicated for asthma treatment;
generally reserved for difficult-tocontrol asthma and when alternatives
have failed
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Administration
• Theophylline and its derivatives are
available in extended-release tablets
and capsules and rectal and injectable
forms.
• For IV administration, aminophylline is
preferred.
• Elimination is extremely variable from
patient to patient, and serum levels are
monitored to avoid toxicity.
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Side Effects
• Due to narrow therapeutic index,
difficulty in dosing, individual response
to drugs, and side effects, use of
theophylline and related drugs is
waning.
• Side effects can include headache,
irritability, nausea, vomiting, CNS
stimulation leading to seizures,
hypotension, and cardiac arrhythmias.
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Tips for the Technician
• Be aware of dosing differences
between theophylline products.
• Be aware that many drugs and
additives are incompatible with
aminophylline intravenous solutions.
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Allergic Rhinitis, Coughs,
and Colds
• Rhinitis—inflammation of mucous
membranes of the nose
– Treatment includes antihistamines,
decongestants, and intranasal application
of corticosteroids.
– Preventative measures, such as
environmental air filters, can be useful.
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Allergic Rhinitis, Coughs,
and Colds (cont’d)
• Cough—a natural response to airway
irritation and aids process of clearing
foreign material
• Coughs can be symptomatic of asthma,
bronchitis, or simple viral infections.
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Antihistamines
• Reversible antagonists of the H1
receptor
• Prevent typical effect of histamine
stimulation at this receptor
• First-generation antihistamines are
nonselective and can activate H1
receptors in the CNS, which accounts
for their sedating effects.
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Antihistamines (cont’d)
• Second-generation, “nonsedating”
antihistamines are selective for
peripheral H1 receptors.
• Indicated for allergic reactions,
including hives and itching of eczema
• Diphenhydramine remains the standard
antihistamine to which other drugs are
compared.
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Administration
• Because of the variety of indications for
use, antihistamines are available in the
following formulations:
– Oral
– Injectable
– Rectal
– Topical
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Side Effects
• Most common side effect of nonspecific
antihistamines is sedation.
• The second-generation antihistamine
cetirizine is most likely to cause
minimal drowsiness.
• Lower antihistamine doses are
recommended for elderly patients.
• Children may exhibit paradoxical
response.
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Tips for the Technician
• Patients should be urged to read
package labeling for warnings and
contraindications of OTC antihistamines.
• Auxiliary labels should be affixed to
prescription warning of potential
sedation and discouraging alcohol
consumption.
• Promethazine suppositories are stored
in refrigerator and labeled accordingly.
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Cough Suppressants,
Decongestants, and
Expectorants
• Colds are the most common form of
infection.
• Patients can be aided with drugs
indicated for short-term treatment of
symptoms accompanying colds and
other upper respiratory infections.
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Actions and Indications
• Pseudoephedrine, phenylephrine,
oxymetazoline, and others are alphaagonists useful as nasal decongestants.
• Opiate cough suppressants, including
codeine, decrease the sensitivity of the
cough centers in the CNS.
• Expectorants such as guaifenesin
promote the removal of sputum from
the lungs.
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Review
A natural way for the body to clear foreign material is
through coughing.
A) True
B) False
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Answer
A) True
Coughing is a natural response to airway
irritation and aids the process of
clearing foreign material.
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Administration
• Nasal decongestants are available as
nasal sprays or drops.
• Pseudoephedrine is most universally
used and is available in tablets,
capsules, chewable tablets, extendedrelease tablets, pediatric liquid, and
infant drops.
• Dextromethorphan is available in
tablets, capsules, and liquids.
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Side Effects
• Rebound congestion can occur with
nasal decongestants.
• Elevation of blood pressure can occur
with oral decongestant; people with
glaucoma and cardiac disease and
patients taking MAO inhibitors should
avoid systemic decongestants.
• Nausea and vomiting may occur with
dextromethorphan or guaifenesin.
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Side Effects (cont’d)
• Both dextromethorphan and
pseudoephedrine carry some risks of
abuse and, by federal law, are stored
behind the prescription counter.
– Dextromethorphan can cause
hallucinations when taken in extremely
high doses.
– Pseudoephedrine can be converted to the
stimulant methamphetamine.
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Tips for the Technician
• Any narcotic antitussive should be
properly labeled with auxiliary warning
instructions regarding drowsiness,
avoidance of operation of complex
machinery, and avoidance of alcohol
consumption.
• Any consumer questions regarding OTC
preparations should be referred to the
pharmacist.
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