Common respiratory diseases
◦ Asthma
◦ Chronic obstructive pulmonary disease (COPD)
◦ Allergic rhinitis
Associated with persisting cough
Asthma is a chronic disease characterized by
hyperresponsive airways
COPD, includes emphysema and chronic
bronchitis
Allergic rhinitis is characterized by itchy, watery
eyes, runny nose, and a nonproductive cough
Coughing is an important defensive respiratory
response to irritants and has been cited as the
number-one reason why patients seek medical
care
A troublesome cough may represent several
etiologies such as:
◦ The common cold
◦ Sinusitis
◦ An underlying chronic respiratory disease
Respiratory conditions can be controlled through
a appropriate lifestyle changes and medications
Drugs can be delivered topically to the nasal
mucosa, inhaled into the lungs, or given orally or
parenterally for systemic absorption
Local delivery methods, such as nasal sprays or
inhalers, are preferred to target affected tissues
while minimizing systemic side effects
Clinically useful drugs mitigate the specific
pathology, such as by relaxing bronchial smooth
muscle or modulating the inflammatory response
Inflammatory disease of the airways characterized
by episodes of acute bronchoconstriction causing
shortness of breath, cough, chest tightness,
wheezing, and rapid respiration
Symptoms may resolve spontaneously, with
nonpharmacologic relaxation exercises, or with use
of “quick-relief” medications, such as a short-
acting β2-adrenergic agonist
Asthma is a chronic disease with an underlying
inflammatory pathophysiology
If untreated, may cause airway remodeling,
resulting in increased severity and incidence of
exacerbations and/ or death
Deaths due to asthma are relatively infrequent
Significant morbidity results in high costs,
numerous hospitalizations, and decreased quality
of life
1. Reducing impairment: by decreasing the intensity
and frequency of asthma symptoms
Prevent chronic and troublesome symptoms
Require infrequent use (≤2 days a week) of
inhaled short-acting β2 agonist for quick relief of
symptoms
Maintain (near) “normal” pulmonary function
Maintain normal activity levels
Meet expectations of the patient and family
2. Reducing risk: decreasing the adverse outcomes
associated with asthma and its treatment
Prevent recurrent exacerbations of asthma, and
minimize the need for emergency department
visits or hospitalizations
Prevent progressive loss of lung function and, for
children, prevent reduced lung growth
Provide optimal pharmacotherapy with minimal or
no adverse effects.
Airflow obstruction in asthma is due to
bronchoconstriction that results from
◦ Contraction of bronchial smooth muscle
◦ Inflammation of the bronchial wall
◦ Increased secretion of mucus
Asthmatic attacks may be related to recent exposure to
allergens or inhaled irritants leading to bronchial
hyperactivity and inflammation of the airway mucosa
The symptoms of asthma may be effectively treated by
several drugs, but no agent provides a cure
Recent research demonstrates a link between β2-
receptor polymorphism and response to LABAs for 16-
20% of asthma patients
Three asthma phenotypes have been reported:
homozygous glycine, heterozygous glycine/arginine,
and homozygous arginine
Patients with the homozygous arginine polymorphism
may be at risk for worsening symptoms with LABA
Clinicians prescribing any new LABA prescription
should counsel patients to carefully monitor symptoms
for any signs of worsening
If the patient reports worsening symptoms, LABA
therapy should be discontinued with a subsequent
increase in corticosteroid dosing as clinically
appropriate
Adrenergic agonists
Corticosteroids
Epinephrine is the drug of choice for treatment of acute
anaphylaxis and status asthmaticus
Leukotriene antagonists
Cromolyn
Cholinergic antagonists
Theophylline
Omalizumab
Inhaled adrenergic agonists with β2 activity are the
drugs of choice for mild asthma
Direct-acting β2 agonists are potent
bronchodilators that relax airway smooth muscle
Quick relief (short acting)
Long term control
Quick relief:
◦ Most clinically useful β2 agonists have a rapid onset of action
(5 to 30 minutes) and provide relief for 4 to 6 hours
◦ They are used for symptomatic treatment of bronchospasm,
providing quick relief of acute bronchoconstriction
◦ Example
Albuterol (USP) =Salbutamol (INN) = (Ventolin®,Ventol ®)
◦ β2 agonists have no anti-inflammatory effects, and they should
never be used as the sole therapeutic agents for patients with
persistent asthma
◦ Monotherapy with short-acting β2 agonists may be appropriate
for patients identified as having intermittent asthma or exercise
induced bronchospasm
Quick relief:
◦ Adverse effects (Tachycardia, hyperglycemia,
hypokalemia, hypomagnesemia) are minimized with
delivery via inhalation
◦ All patients with asthma should be prescribed a quick-
relief inhaler and regularly assessed for appropriate
inhaler technique
Long-term control:
Long-acting β2-agonists (LABAs)
◦ Salmeterol
◦ Formoterol
Provide bronchodilation for at least 12 hours
Have slower onsets of action and should not be used
for quick relief of an acute asthma attack
Use of a LABA alone is contraindicated in asthma, and
the single-ingredient LABAs should be used in
combination with an asthma controller medication
Inhaled corticosteroids remain the long-term control
drugs of choice in asthma
Inhaled corticosteroids (ICS) are the drugs of first
choice in patients with any degree of persistent
asthma
Severe persistent asthma may require the addition
of a short course of oral glucocorticoid treatment
No other medications are as effective as ICS in the
long-term control of asthma
To be effective in controlling inflammation
glucocorticoids must be taken regularly
Current guidelines recommend selecting ICS
therapy for a newly diagnosed patient with asthma
Patients achieving 3 to 6 consecutive months of
improved asthma control may be considered for a
reduction in ICS dosing
Actions on lung
ICS therapy directly targets underlying airway
inflammation by:
◦ Decreasing the inflammatory cascade (eosinophils,
macrophages, and T lymphocytes)
◦ Reversing mucosal edema
◦ Decreasing the permeability of capillaries
◦ Inhibiting the release of leukotrienes
◦ After several months of regular use, ICS reduce the hyper-
responsiveness of the airway smooth muscle to a variety
of bronchoconstrictor stimuli, such as allergens, irritants,
cold air, and exercise
Routes of administration:
Inhalation
Oral
Spacers
Inhalation
The development of ICS has markedly reduced the need for
systemic corticosteroid treatment to achieve asthma control
Appropriate inhalation technique is critical for success of
therapy
Patients should be instructed to slowly and deeply inhale
just before and throughout activation of MDIs to avoid
impaction of the medication onto the laryngeal mucosa
rather than the bronchial smooth muscle
For DPIs; patients should be instructed to inhale quickly and
deeply to optimize drug delivery to the lungs
Corticosteroid deposition on the oral and laryngeal mucosa
can cause adverse effects, such as oropharyngeal
candidiasis and hoarseness due to local immune
suppression
◦ Patients should rinse their mouth with water after administration
Patients with severe exacerbation of asthma (status
asthmaticus) may require IV administration of
methylprednisolone or oral prednisone
Once the patient has improved, the dose of drug is
gradually reduced, and discontinued in 1 to 2
weeks
In most cases, suppression of the HPA axis will not
occur during the short course of oral prednisone
typically prescribed for an asthma exacerbation
◦ Dose reduction is not necessary
A spacer is a large-volume chamber
attached to a MDI
Spacers decrease the deposition of drug
in the mouth caused by improper inhaler
technique
The chamber reduces the velocity of the
aerosol before entering the mouth,
allowing large drug particles to be
deposited in the device
The smaller, higher-velocity drug
particles are less likely to be deposited in
the mouth and more likely to reach the
airway tissue
Spacers minimize the problem of adrenal
suppression by reducing the amount of
glucocorticoid deposited in the oro-pharynx
Spacers improve delivery of inhaled glucocorticoids
and are advised for virtually all patients
◦ Especially children less than 5 years old and elderly
patients who may have difficulty coordinating actuation
with inhalation
Patients should be counseled about regular
washing and/or rinsing of spacers to reduce the
risk of bacterial or fungal growth inducing an
asthma attack
Oral or parenteral glucocorticoids have a variety of
potentially serious side effects
ICS if used with a spacer, have few systemic effects
Effect of ICS on bone growth in children is
negligible
◦ The retardation of vertical bone growth secondary to low
oxygenated blood from uncontrolled asthma can occur in
more severe cases
Leukotriene antagonists
Cromolyn
Cholinergic antagonists
Theophylline
Omalizumab
Leukotrienes are products of the 5-lipoxygenase
pathway of arachidonic acid metabolism and part
of the inflammatory cascade
5-Lipoxygenase is found in cells of myeloid origin,
such as mast cells, basophils, eosinophils, and
neutrophils
LTB4 is a potent chemoattractant for neutrophils
and eosinophils
Cysteinyl leukotrienes (LTC4, LTD4, LTE4) constrict
bronchiolar smooth muscle, increase endothelial
permeability, and promote mucus secretion
Montelukast (Singulair®)
Zileuton
Zafirlukast
Zileuton is a selective and specific inhibitor of 5-
lipoxygenase, preventing the formation of both
LTB4 and the cysteinyl leukotrienes
Zafirlukast and montelukast are selective,
reversible inhibitors of the cysteinyl leukotriene-1
receptor, they block the effects of cysteinyl
leukotrienes
Montelukast
◦ Can be used in children 6 months of age and older
◦ Available in chewable tablets and granule formulations
Approved for the prophylaxis of asthma but are
not effective in situations in which immediate
bronchodilation is required
Therapeutic benefits
◦ Modest reductions in the doses of β2-adrenergic agonists
and corticosteroids
◦ Improved respiratory function
Montelukast is approved for prevention of
exercise-induced bronchospam
Elevations in serum hepatic enzymes
◦ Require periodic monitoring and discontinuation when
enzymes exceed three to five times the upper limit of normal
Although rare, eosinophilic vasculitis (Churg-Strauss
syndrome) has been reported with all agents,
particularly when the dose of concurrent
glucocorticoids is reduced
Headache
Dyspepsia
Both zafirlukast and zileuton are inhibitors of
cytochrome P450
◦ Can increase serum levels of warfarin
Cromolyn is an effective prophylactic anti-
inflammatory agent
Inhibits mast cell degranulation and release of
histamine
It is not useful in managing an acute asthma attack
because it is not a direct bronchodilator
Can block the initiation of immediate and delayed
asthmatic reactions
Cromolyn is available as a nebulized solution
Because it is poorly absorbed, only minor adverse
effects are associated with it
Pretreatment with cromolyn blocks allergen- and
exercise-induced bronchoconstriction
Given its safety, an initial trial of cromolyn is often
recommended, particularly in children and pregnant
women
Has short duration of action, requires frequent daily
dosing, which has been shown to affect adherence and
therapeutic efficacy
Should not replace ICS or quick-relief β2 agonists as
the mainstay of asthma therapy
Ipratropium
Tiotropium
Less effective than β2-adrenergic agonists
Block the vagally mediated contraction of airway
smooth muscle and mucus secretion
Useful in patients who are unable to tolerate
adrenergic agonists
Not traditionally effective for patients with asthma
unless COPD is also present
A bronchodilator that relieves airflow obstruction
in chronic asthma and decreases its symptoms
Theophylline is well absorbed by the GIT
Several sustained-release preparations are
available
Has been largely replaced with β2 agonists and
corticosteroids
◦ Theophylline has a narrow therapeutic window
◦ High side effect profile
◦ Potential for drug interactions
No longer recommended for acute bronchospasm
or status asthmaticus
Overdose may cause seizures or potentially fatal
arrhythmias
Metabolized in the liver by CYP1A2 and 3A4, and
interacts adversely with many drugs
Recombinant DNA-derived monoclonal antibody that
selectively binds to human immunoglobulin E (IgE)
This leads to decreased binding of IgE to the high-
affinity IgE receptor on the surface of mast cells and
basophils
Reduction in surface bound IgE limits the degree of
release of mediators of the allergic response
Omalizumab may be particularly useful for treatment
of moderate to severe allergic asthma in patients who
are poorly controlled with conventional therapy
COPD is a chronic, irreversible obstruction of airflow
Smoking is the greatest risk factor for COPD and is
directly linked to the progressive decline of lung
function
Smoking cessation and/or continued avoidance is
recommended regardless of stage/severity of COPD
and age of patient
Inhaled bronchodilators such as
◦ Anticholinergic agents (ipratropium, tiotropium)
◦ β2-adrenergic agonists (albuterol, salmeterol)
These drugs increase airflow, alleviate symptoms, and decrease
exacerbation of disease
Addition of a long-acting β2 agonist, such as salmeterol, improves lung
function and quality of life, while decreasing frequency of exacerbations
ICS should be restricted to patients with an FEV in 1 second of less than 50
percent of predicted
ICS may provide symptomatic relief, but the progressive decline in FEV1 is
not impacted
Roflumilast
Oral phosphodiesterase-4 inhibitor used to reduce
exacerbations in patients with severe COPD
Reduce inflammation by increasing levels of
intracellular cAMP in lung cells.
Not a bronchodilator and is not indicated for the
relief of acute bronchospasm
Side effects: nausea, vomiting, diarrhea, and
headache.
Rhinitis is an inflammation of the mucous membranes
of the nose
Characterized by sneezing, itchy nose/eyes, watery
rhinorrhea, and nasal congestion
An attack may be precipitated by inhalation of an
allergen (pollen, dust)
The foreign material interacts with mast cells coated
with IgE generated in response to a previous allergen
exposure
The mast cells release mediators, such as histamine,
leukotrienes, promote bronchiolar spasm and mucosal
thickening from edema and cellular infiltration
Combinations of oral antihistamines with
decongestants are the first-line therapies for
allergic rhinitis
Systemic effects associated with oral preparations
(sedation, insomnia, and, rarely, cardiac
arrhythmias) make topical intranasal delivery of
drugs more favorable
Antihistamines (H1-receptor blockers)
α- Adrenergic agonists
Corticosteroids
Cromolyn
Leukotrienes antagonists
The most frequently used agents in the treatment of
sneezing and watery rhinorrhea associated with
allergic rhinitis
First generation antihistamines
◦ Diphenhydramine
◦ Chlorpheniramine (Ahiston®, Allergon®)
Second generation antihistamines
◦ Loratadine (Allergyx®, Claristine®, Lorax®, Loradin®)
◦ Fexofenadine (Telfast®, Fexodin®)
Useful in treating the symptoms of allergic rhinitis
caused by histamine release
Ocular and nasal antihistamine delivery devices are
available
Antihistamines differ in their ability to cause
sedation and in their duration of action
Adverse effects
◦ Sedation (first generation)
◦ Anticholinergic side effects of the firstgeneration
antihistamines (dry eyes/mouth, difficulty urinating
and/or defecating) are transient and may resolve in 7 to
10 days
◦ Constipation
Constrict dilated arterioles in the nasal mucosa and
reduce airway resistance
Short-acting: Phenylephrine
Longer-acting: Oxymetazoline (Nosacare®)
When administered as an aerosol, these drugs have a
rapid onset of action and show few systemic effects
The α-adrenergic agonist nasal formulations should be
used no longer than 3 days due to the risk of rebound
nasal congestion (rhinitis medicamentosa)
Never used for long-term treatment of allergic rhinitis
Beclomethasone
Budesonide
Fluticasone
Flunisolide
Ciclesonide
Mometasone
Triamcinolone
Effective when administered as nasal sprays
◦ Minimal systemic absorption
◦ Localized side effects: nasal irritation, nosebleed, sore
throat, candidiasis (rare)
Patients should be told not to deeply inhale while
administering these drugs
Treatment of chronic rhinitis may not result in
improvement until 1 to 2 weeks after starting
therapy
Cromolyn
◦ Intranasal cromolyn may be useful, particularly when
administered before contact with an allergen (1-2 weeks)
◦ Due to a short duration of action, cromolyn requires
multiple daily dosing
Leukotriene antagonists (montelukast)
◦ Indicated for treatment of both seasonal and perennial
allergic rhinitis
Codeine
The standard treatment for cough suppression
Decreases the sensitivity of cough centers in the
central nervous system to peripheral stimuli and
decreases mucosal secretion
Cough suppression occurs at lower doses than
analgesia
Common sides effects:
◦ Constipation, dysphoria, and fatigue, addiction
Dextromethorphan
Synthetic derivative of morphine that suppresses
the response of the central cough center
◦ No analgesic effects in antitussive doses
Low addictive profile, may cause dysphoria at
high doses, which may explain its status as a
potential drug of abuse
Better side effect profile than codeine
Guaifenesin
Expectorant
Available as a single-ingredient formulation
Found in combination products with codeine or
dextromethorphan
Benzonatate
Unlike the opioids, it suppresses the cough reflex
through peripheral action
It anesthetizes the stretch receptors located in the
respiratory passages, lungs, and pleura
Side effects include dizziness, numbness of the
tongue, mouth, and throat
