Transcript Roach: Introductory Clinical Pharmacology

Introduction to Clinical
Pharmacology
Chapter 31Upper Respiratory Drugs
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Antihistamine: Actions
• Antihistamines blocks most, but not all the effects of
histamine
• First-generation antihistamines bind nonselectively
to central and peripheral H1 receptors and may
result in CNS stimulation or depression
• Other first-generation drugs may have additional
effects- antipruritic (anti-itching) or antiemetic
(anti-nausea) effects
• Second-generation antihistamines are selective for
peripheral H1 receptors and, as a group are less
sedating
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Antihistamine: Uses
• The general uses of the antihistamines include:
– Relief of the symptoms of seasonal and
perennial allergies; allergic and vasomotor
rhinitis; allergic conjunctivitis; mild and
uncomplicated angioneurotic edema and
urticaria; relief of allergic reactions to drugs,
blood, or plasma; relief of coughs caused by
colds or allergy; adjunctive therapy in
anaphylactic shock; treatment of
parkinsonism; relief of nausea and vomiting;
relief of motion sickness; sedation; adjuncts
to analgesics
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Antihistamine: Adverse Reactions
• Central nervous system reactions –
– Drowsiness or sedation; disturbed
coordination-loratadine/claritin-does not
cause drowsiness
• Anticholinergic effects (cholinergic
blocking)– Dryness of mouth, nose, and throat;
thickening of bronchial secretion
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Antihistamine: Contraindications and
Precautions
• Contraindicated: During pregnancy and
lactation
– First-generation antihistamine: Patients
with known hypersensitivity to the drugs,
newborns, premature infants, nursing
mothers, individuals undergoing
monamine oxidase therapy and in
patients with angle-closure glaugoma,
stenosing peptic ulcer, symptomatic
prostatic hypertrophy, and bladder neck
obstruction
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Antihistamine: Contraindications and
Precautions (cont’d)
– Second-generation antihistamines: patients
with known hypersensitivity
– Cetirizine is contraindicated in patients who
are hypersensitive to hydroxyzine
• Used with caution in patient with: bronchial
asthma, cardiovascular disease, narrow-angle
glaucoma, symptomatic prostatic hypertrophy,
hypertension, impaired kidney function, peptic
ulcer, urinary retention, pyloroduodenal
obstruction, and hyperthyroidism
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Decongestants: Actions and Uses
• Actions:
– Nasal decongestants: Sympathomimetic drugs,
which produce localized vasoconstriction of the
small blood vessels of the nasal membranesreduces swelling of the nasal passages
• Uses:
– Used to treat the congestion associated with
the following conditions:
• Common cold; hay fever; sinusitis; allergic
rhinitis; congestion associated with rhinitis
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Decongestants: Adverse Reactions and
Contraindications
• Use of oral decongestants may result in the following
adverse reactions:
– Tachycardia and other cardiac arrhythmias;
nervousness; restlessness; insomnia; blurred
vision; nausea; vomiting
• Contraindicated:
– patients with known hypersensitivity and patients
taking monoamine oxidase inhibitors
– Sustained-released pseudoephedrine is
contraindicated in children below 12 years of age
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Decongestants: Precautions
• Decongestants are used cautiously in
patients with:
– Thyroid disease; diabetes mellitus;
cardiovascular disease; prostatic
hypertrophy; coronary artery disease;
peripheral vascular disease;
hypertension; glaucoma
– Pregnant women should consult with their
primary health care provider before using
these drugs
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Decongestants: Interactions
Interactant drug
Effect of interaction
MAOIs
Severe headache,
hypertension and
possibly hypertensive
crisis
Initial hypertension
episode followed by
bradycardia
Beta-adrenergic
blocking drugs
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Antitussives, expectorants and
mucolytics: Actions and Uses
• Some antitussives depress cough center
located in medulla and are called centrally
acting drugs
• Some antitussives are peripherally acting
drugs, which act by anesthetizing stretch
receptors in the respiratory passages,
thereby decreasing coughing
• Antitussives are used to relieve
nonproductive cough
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Mucolytics and Expectorants: Actions
• Drug with mucolytic activity appears to
reduce viscosity of respiratory secretions by
direct action on mucus
• Expectorants increase production of
respiratory secretions, which in turn appears
to decrease viscosity of mucus, helps to
raise secretions from respiratory passage
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Antitussives, expectorants and
mucolytics : Adverse Reactions
• Central nervous system reactions:
– Sedation; dizziness; lightheadedness
• Gastrointestinal reactions:
– Nausea; vomiting; constipation
 Nonprescription cough medicines containing
two or more ingredients produce few
adverse reactions when used as directed
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Antitussives, expectorants and
mucolytics : Contraindications and
Precautions
• Contraindicated in patients with known
hypersensitivity to drugs
• Opioid antitussives are contraindicated in
premature infants or during labor when
delivery of premature infant is anticipated
• Expectorant potassium iodide is
contraindicated during pregnancy-D
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Antitussives, expectorants and mucolytics :
Contraindications and Precautions
• Used with caution in patients:
– With persistent or chronic cough; cough
accompanied by excessive secretions;
high fever; rash; persistent headache or
nausea or vomiting
• Expectorants are used cautiously during
pregnancy and lactation and in patients with:
– Persistent cough; severe respiratory
insufficiency or asthma; older adults or
debilitated patients
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Antitussives, expectorants and
mucolytics : Contraindications and
Precautions (cont’d)
• Antitussives containing codeine are used
with caution during pregnancy and labor and
in patients with COPD; acute asthmatic
attack; preexisting respiratory disorders;
acute abdominal conditions
• Opioid antitussives are used cautiously in
patients with head injury and increased
intracranial pressure; acute abdominal
disorders; convulsive disorders; hepatic or
renal impairment; prostatic hypertrophy;
asthma or other respiratory conditions
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Antitussives, expectorants and
mucolytics : Interactions
• Central nervous system (CNS) depressants
and alcohol may cause additive depressant
effects when administered with antitussives
containing codeine
• When dextromethorphan is administered
with monoamine oxidase inhibitors, patients
may experience hypotension, fever, nausea,
jerking motions to the leg, coma
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Antitussives, Mucolytics and
Expectorants: Interactions (cont)
• Patient may experience hypokalemia;
cardiac arrhythmias; or cardiac arrest when
potassium-containing medications and
potassium-sparing diuretics are administered
with iodine products
• Thyroid function tests may also be altered by
iodine
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Herbal Alert
• Eucalyptus
– Used as a decongestant and expectorant-found as a
component in OTC products for tx of sinusitis and
pharyngitis
• Should not be used during pregnancy and
lactation, children younger than 2 years of age
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Nursing Process: Assessment
• Preadministration assessment:
– Document type of cough and describe
color and amount of any sputum present
during preadministration assessment
– Record vital signs as some patients with
productive cough may have an infection
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Nursing Process: Assessment
• Ongoing assessment:
– Observe for therapeutic effect
– Auscultate lung sounds, takes vital signs
periodically
– Describe and record in chart type of
cough and frequency of coughing
– Record whether cough interrupts sleep or
causes pain in chest or other parts of
body
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Ongoing Assessment
• If a cough is present, describe in your documentation the
type of cough (productive or nonproductive) and the
frequency
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Nursing Process: Planning
• Expected outcome includes:
– Optimal response to therapy
– Support of patient needs related to
managing adverse drug reactions
– Understanding of and compliance with
prescribed treatment regimen
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Nursing Process: Implementation
• Promoting an optimal response to therapy:
– Administer antitussives orally
– Depression of cough reflex can cause
secretions to pool in lungs
– Indiscriminate use of antitussives by
general public may prevent early
diagnosis and treatment of serious
disorders, such as lung cancer and
emphysema
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Nursing Process: Implementation
• Promoting an optimal response to therapy: Teaching
– Fexofenadine: Not administered 2 hours after
antacids
Immediately before and after tx with
acetylcysteine, Auscultate lungs and record
findings of both assessments on client’s chart
*If inserted into trach, keep suction available!
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Nursing Process: Implementation
• Monitoring and managing patient’s needs:
– Impaired oral mucous membrane:
• Dryness of the mouth, nose, and throat- offer the
patient frequent sips of water or ice chips to
relieve the symptom
– Risk of injury:
• Assist the patient with ambulation
• Place the call light within easy reach and instruct
to call before attempting to get out of bed and
ambulating
GERIATRICs- older adults are likely to experience
injury from dizziness due to sensorimotor deficits
such as hearing loss, visual impairments, or
unsteady gait
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Nursing Process: Implementation
• Educating the patient and family:
– Advise patient to read label carefully, follow
dosage recommendations, and consult primary
health care provider if cough persists for more
than 10 days or if fever or chest pain occurs
– If taking oral capsules, do not chew or break
open the capsules, swallow them whole
– Do not use with alcohol or other CNS
depressants-antidepressants, hypnotics,
sedatives, tranquilizers
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Implement: educate
– Nasal burning and stinging may occur with the
topical decongestants-effect disappears after use
– If using a spray decongestant, do not allow the
tip of the container to touch the nasal mucosa
and do not share the container with anyone
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Nursing Process: Implementation
• Ineffective Airway Clearance
– Take deep breaths
– Instruct on diaphragmatic breathing
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Nursing Process: Implementation• Educating the patient and family:
– Nurse reviews the dosage regimen and
possible adverse drug reactions with the
patient
– Antihistamines may cause dryness of the
mouth and throat-provide frequent sips
of water, suck on hard candy, chew gum
– If gastric upset occurs, take this drug
with food or meals
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Nursing Process: Eval
• No evidence of injury
• Patient has a clear airway
• Mucous membranes are dry and intact
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