respiratoy drugs outline

PharmacologyPharmacologyPharmacologyPharmacology

Drugs used to treat:

Asthma

Rhinitis & Cough

Drugs used to treat:

Asthma

Rhinitis & Cough

TopicsTopicsTopicsTopics

• Bronchodilators• Methylxanthines• Anticholinergics• Anti-inflammatory

Agents• Leukotriene

Antagonists• Mast cell stabilizers

• Bronchodilators• Methylxanthines• Anticholinergics• Anti-inflammatory

Agents• Leukotriene

Antagonists• Mast cell stabilizers

• Decongestants• Antihistamines• Antitussives• Expectorants &

mucolytics

• Decongestants• Antihistamines• Antitussives• Expectorants &

mucolytics

AsthmaAsthmaAsthmaAsthma

• Inflammatory response to allergen

• Antibody binds with & ruptures mast cells– Releases histamine, prostaglandins,

leukotrienes

• Two primary issues– Bronchoconstriction– Inflammation (mucous production)

• Inflammatory response to allergen

• Antibody binds with & ruptures mast cells– Releases histamine, prostaglandins,

leukotrienes

• Two primary issues– Bronchoconstriction– Inflammation (mucous production)

Approaches to TreatmentApproaches to TreatmentApproaches to TreatmentApproaches to Treatment

• Relax bronchial smooth muscle– ß2 agonists– methylxanthines– anticholinergics

• Inhibit release of mediators– Glucocorticoids– Mast cell stabilizers

• Block affects of mediators– Leukotriene antagonists

• Relax bronchial smooth muscle– ß2 agonists– methylxanthines– anticholinergics

• Inhibit release of mediators– Glucocorticoids– Mast cell stabilizers

• Block affects of mediators– Leukotriene antagonists

BronchodilatorsBronchodilatorsBronchodilatorsBronchodilators

ß2 agonists albuterol (Proventil®),

metaproterenol (Alupent®)

terbutaline (Breathair®)

Nonselective epinephrine (Adrenalin®)

Methylxanthines theophylline (TheoDur®)

aminophyllin, (Aminophylline®)

Anticholinergics ipratropium bromide (Atrovent®)

Antiinflammatory AgentsAntiinflammatory AgentsAntiinflammatory AgentsAntiinflammatory AgentsGlucocorticoids

inhaled beclomethasone (Beclovent®)

flucticasone (Flovent®)

oral prednisolone (Deltasone®)

injected methylprednisolone (Solu-Medrol®)

dexamethasone (Decadron®)

Mast cell Stabilizer cromolyn (Nasalcrom®, Intal®)

Leukotriene Antagonists zafirlukast (Accolate®)

zileuton (Zyflo®)

Colds and AllergiesColds and AllergiesColds and AllergiesColds and Allergies

• Nasal Inflammation– Vasodilation & engorgement

• Itching, redness, rhinorrhea– Mast/basophil degranulation

• Nasal Inflammation– Vasodilation & engorgement

• Itching, redness, rhinorrhea– Mast/basophil degranulation

Nasal DecongestantsNasal DecongestantsNasal DecongestantsNasal Decongestants

congestion via vasodilation

• Alpha1 stimulation– Topical administration

congestion via vasodilation

• Alpha1 stimulation– Topical administration

• phenylephrine (Neo-Synephrine®)

• pseudoephedrine (Sudafed®, Actifed®)

• A moment of silence for:– phenylpropanolamine

(AlkaSeltzer Cold®, Contact®, Allerest®)

• phenylephrine (Neo-Synephrine®)

• pseudoephedrine (Sudafed®, Actifed®)

• A moment of silence for:– phenylpropanolamine

(AlkaSeltzer Cold®, Contact®, Allerest®)

AntihistaminesAntihistaminesAntihistaminesAntihistamines

• H1 receptors– Vasodilation

– Increased capillary permeability

– Bronchoconstriction

• H2 receptors– Increase gastric acid

secretion (Zantac®), etc)

• H1 receptors– Vasodilation

– Increased capillary permeability

– Bronchoconstriction

• H2 receptors– Increase gastric acid

secretion (Zantac®), etc)

• Other histamine receptors– Sedation

• Other histamine receptors– Sedation

Antihistamine AgentsAntihistamine AgentsAntihistamine AgentsAntihistamine Agents

• First generation– Sedation

• chlorpheniramine (Chlor-Trimeton®)

• diphenhydramine (Benadry®)

• clemastine (Tavist®)• promethazine

(Phergan®)

• First generation– Sedation

• chlorpheniramine (Chlor-Trimeton®)

• diphenhydramine (Benadry®)

• clemastine (Tavist®)• promethazine

(Phergan®)

• Second generation– No sedation – blood-brain barrier

• Sniff, sniff:– terfenadine (Seldane®)

• fexofenadine (Allegra®)

• cetirizine (Zyrtec®)• loratadine (Claritin®)

• Second generation– No sedation – blood-brain barrier

• Sniff, sniff:– terfenadine (Seldane®)

• fexofenadine (Allegra®)

• cetirizine (Zyrtec®)• loratadine (Claritin®)

Cough SuppressantsCough SuppressantsCough SuppressantsCough Suppressants

• Antitussives– Decrease cough reflex

– Opioids• codeine & hydrocodone

– Non-opioids• dextromethorphan

• benzonatate (Tessalon®)

• Antitussives– Decrease cough reflex

– Opioids• codeine & hydrocodone

– Non-opioids• dextromethorphan

• benzonatate (Tessalon®)

• Expectorants– guaifenesin may work

– others are doubtful

• Mucolytics– Decreases viscocity

– acetlycysteine (Mucomyst®)

– hypertonic saline

• Expectorants– guaifenesin may work

– others are doubtful

• Mucolytics– Decreases viscocity

– acetlycysteine (Mucomyst®)

– hypertonic saline

Antihistamines,

Decongestants,

Antitussives,

and

Expectorants

Antihistamines,

Decongestants,

Antitussives,

and

Expectorants

Drugs Affecting theDrugs Affecting theRespiratory SystemRespiratory SystemDrugs Affecting theDrugs Affecting theRespiratory SystemRespiratory System

Understanding the Common Understanding the Common ColdColdUnderstanding the Common Understanding the Common ColdCold• Most caused by viral infection

(rhinovirus or influenza virus—the “flu”)

• Most caused by viral infection (rhinovirus or influenza virus—the “flu”)

Understanding the Common Understanding the Common ColdColdUnderstanding the Common Understanding the Common ColdCold• Virus invades tissues (mucosa) of upper

respiratory tract, causing upper respiratory infection (URI).

• Excessive mucus production results from the inflammatory response to this invasion.

• Fluid drips down the pharynx into the esophagus and lower respiratory tract, causing cold symptoms: sore throat, coughing, upset stomach.

• Virus invades tissues (mucosa) of upper respiratory tract, causing upper respiratory infection (URI).

• Excessive mucus production results from the inflammatory response to this invasion.

• Fluid drips down the pharynx into the esophagus and lower respiratory tract, causing cold symptoms: sore throat, coughing, upset stomach.

Understanding the Common Understanding the Common ColdColdUnderstanding the Common Understanding the Common ColdCold• Irritation of nasal mucosa often triggers the

sneeze reflex.

• Mucosal irritation also causes release of several inflammatory and vasoactive substances, dilating small blood vessels in the nasal sinuses and causing nasal congestion.

• Irritation of nasal mucosa often triggers the sneeze reflex.

• Mucosal irritation also causes release of several inflammatory and vasoactive substances, dilating small blood vessels in the nasal sinuses and causing nasal congestion.

Treatment of the Common Treatment of the Common ColdColdTreatment of the Common Treatment of the Common ColdCold• Involves combined use of antihistamines,

nasal decongestants, antitussives, and expectorants.

• Treatment is SYMPTOMATIC only, not curative.

• Symptomatic treatment does not eliminate the causative pathogen.

• Involves combined use of antihistamines, nasal decongestants, antitussives, and expectorants.

• Treatment is SYMPTOMATIC only, not curative.

• Symptomatic treatment does not eliminate the causative pathogen.

Treatment of the Common Treatment of the Common ColdColdTreatment of the Common Treatment of the Common ColdCold• Difficult to identify whether cause is viral

or bacterial.

• Treatment is “empiric therapy,” treating the most likely cause.

• Antivirals and antibiotics may be used, but viral or bacterial cause may not be easily identified.

• Difficult to identify whether cause is viral or bacterial.

• Treatment is “empiric therapy,” treating the most likely cause.

• Antivirals and antibiotics may be used, but viral or bacterial cause may not be easily identified.

AntihistaminesAntihistaminesAntihistaminesAntihistamines

Drugs that directly compete with histamine for specific receptor sites.

• Two histamine receptors:– H1 histamine-1

– H2 histamine-2

Drugs that directly compete with histamine for specific receptor sites.

• Two histamine receptors:– H1 histamine-1

– H2 histamine-2

AntihistaminesAntihistaminesAntihistaminesAntihistamines

H2 Blockers or H2 Antagonists

– Used to reduce gastric acid in PUD– Examples: cimetidine (Tagamet),

ranitidine (Zantac), or famotidine

(Pepcid)

H2 Blockers or H2 Antagonists

– Used to reduce gastric acid in PUD– Examples: cimetidine (Tagamet),

ranitidine (Zantac), or famotidine

(Pepcid)

AntihistaminesAntihistaminesAntihistaminesAntihistamines

H1 antagonists are commonly referred to asantihistamines

• Antihistamines have several effects:– Antihistaminic– Anticholinergic– Sedative

H1 antagonists are commonly referred to asantihistamines

• Antihistamines have several effects:– Antihistaminic– Anticholinergic– Sedative

Antihistamines: Mechanism of Antihistamines: Mechanism of ActionActionAntihistamines: Mechanism of Antihistamines: Mechanism of ActionActionBLOCK action of histamine at the receptor

sites• Compete with histamine for binding at unoccupied

receptors.

• CANNOT push histamine off the receptor if already bound.

BLOCK action of histamine at the receptor sites

• Compete with histamine for binding at unoccupied receptors.

• CANNOT push histamine off the receptor if already bound.

Antihistamines: Mechanism of Antihistamines: Mechanism of ActionActionAntihistamines: Mechanism of Antihistamines: Mechanism of ActionAction• The binding of H1 blockers to the histamine

receptors prevents the adverse consequences of histamine stimulation:– Vasodilation– Increased gastrointestinal and respiratory

secretions– Increased capillary permeability

• The binding of H1 blockers to the histamine receptors prevents the adverse consequences of histamine stimulation:– Vasodilation– Increased gastrointestinal and respiratory

secretions– Increased capillary permeability

Antihistamines: Mechanism of Antihistamines: Mechanism of ActionActionAntihistamines: Mechanism of Antihistamines: Mechanism of ActionAction• More effective in preventing the actions of

histamine rather than reversing them

• Should be given early in treatment, before all the histamine binds to the receptors

• More effective in preventing the actions of histamine rather than reversing them

• Should be given early in treatment, before all the histamine binds to the receptors

Histamine vs. Antihistamine Histamine vs. Antihistamine EffectsEffectsHistamine vs. Antihistamine Histamine vs. Antihistamine EffectsEffectsCardiovascular (small blood vessels)• Histamine effects:

– Dilation and increased permeability (allowing substances to leak into tissues)

• Antihistamine effects:

– Prevent dilation of blood vessels – Prevent increased permeability

Cardiovascular (small blood vessels)• Histamine effects:

– Dilation and increased permeability (allowing substances to leak into tissues)

• Antihistamine effects:

– Prevent dilation of blood vessels – Prevent increased permeability

Histamine vs. Antihistamine Histamine vs. Antihistamine EffectsEffectsHistamine vs. Antihistamine Histamine vs. Antihistamine EffectsEffectsSmooth Muscle (on exocrine glands)• Histamine effects:

– Stimulate salivary, gastric, lacrimal, and bronchial secretions

• Antihistamine effects:

– Prevent salivary, gastric, lacrimal, and bronchial secretions

Smooth Muscle (on exocrine glands)• Histamine effects:

– Stimulate salivary, gastric, lacrimal, and bronchial secretions

• Antihistamine effects:

– Prevent salivary, gastric, lacrimal, and bronchial secretions

Histamine vs. Antihistamine Histamine vs. Antihistamine EffectsEffectsHistamine vs. Antihistamine Histamine vs. Antihistamine EffectsEffectsImmune System

(Release of substances commonly associated with allergic reactions)

• Histamine effects:

– Mast cells release histamine and other substances, resulting in allergic reactions.

• Antihistamine effect:

– Binds to histamine receptors, thus preventing histamine from causing a response.

Immune System

(Release of substances commonly associated with allergic reactions)

• Histamine effects:

– Mast cells release histamine and other substances, resulting in allergic reactions.

• Antihistamine effect:

– Binds to histamine receptors, thus preventing histamine from causing a response.

Antihistamines: Other EffectsAntihistamines: Other EffectsAntihistamines: Other EffectsAntihistamines: Other Effects

Skin:• Block capillary permeability, wheal-and-flare formation,

itching

Anticholinergic:• Drying effect that reduces nasal, salivary, and lacrimal

gland secretions (runny nose, tearing, and itching eyes)

Sedative:• Some antihistamines cause drowsiness

Skin:• Block capillary permeability, wheal-and-flare formation,

itching

Anticholinergic:• Drying effect that reduces nasal, salivary, and lacrimal

gland secretions (runny nose, tearing, and itching eyes)

Sedative:• Some antihistamines cause drowsiness

Antihistamines: Therapeutic Antihistamines: Therapeutic UsesUsesAntihistamines: Therapeutic Antihistamines: Therapeutic UsesUsesManagement of:

• Nasal allergies

• Seasonal or perennial allergic rhinitis (hay fever)

• Allergic reactions

• Motion sickness

• Sleep disorders

Management of:

• Nasal allergies

• Seasonal or perennial allergic rhinitis (hay fever)

• Allergic reactions

• Motion sickness

• Sleep disorders

AntihistaminesAntihistaminesAntihistaminesAntihistamines10 to 20% of general population is sensitive

to various environmental allergies.• Histamine-mediated disorders:

– Allergic rhinitis (hay fever, mold and dust allergies)

– Anaphylaxis

– Angioneurotic edema

– Drug fevers

– Insect bite reactions

– Urticaria (itching)

10 to 20% of general population is sensitive to various environmental allergies.

• Histamine-mediated disorders:– Allergic rhinitis

(hay fever, mold and dust allergies)

– Anaphylaxis

– Angioneurotic edema

– Drug fevers

– Insect bite reactions

– Urticaria (itching)

Antihistamines: Therapeutic Antihistamines: Therapeutic UsesUsesAntihistamines: Therapeutic Antihistamines: Therapeutic UsesUsesAlso used to relieve symptoms associated

with the common cold:• Sneezing, runny nose

• Palliative treatment, not curative

Also used to relieve symptoms associated with the common cold:

• Sneezing, runny nose

• Palliative treatment, not curative

Antihistamines: Side effectsAntihistamines: Side effectsAntihistamines: Side effectsAntihistamines: Side effects

• Anticholinergic (drying) effects, most common:– Dry mouth– Difficulty urinating– Constipation– Changes in vision

• Drowsiness– (Mild drowsiness to deep sleep)

• Anticholinergic (drying) effects, most common:– Dry mouth– Difficulty urinating– Constipation– Changes in vision

• Drowsiness– (Mild drowsiness to deep sleep)

Antihistamines: Two TypesAntihistamines: Two TypesAntihistamines: Two TypesAntihistamines: Two Types

• Traditional

or

• Nonsedating/Peripherally Acting

• Traditional

or

• Nonsedating/Peripherally Acting

Antihistamines:Antihistamines:Antihistamines:Antihistamines:

Traditional• Older

• Work both peripherally and centrally

• Have anticholinergic effects, making them more effective than nonsedating agents in some cases

Examples: diphenhydramine (Benadryl)chlorpheniramine (Chlor-Trimeton)

Traditional• Older

• Work both peripherally and centrally

• Have anticholinergic effects, making them more effective than nonsedating agents in some cases

Examples: diphenhydramine (Benadryl)chlorpheniramine (Chlor-Trimeton)

Antihistamines:Antihistamines:Antihistamines:Antihistamines:

Nonsedating/Peripherally Acting• Developed to eliminate unwanted side effects, mainly

sedation

• Work peripherally to block the actions of histamine; thus, fewer CNS side effects

• Longer duration of action (increases compliance)

Examples: fexofenadine (Allegra)

loratadine (Claritin)

Nonsedating/Peripherally Acting• Developed to eliminate unwanted side effects, mainly

sedation

• Work peripherally to block the actions of histamine; thus, fewer CNS side effects

• Longer duration of action (increases compliance)

Examples: fexofenadine (Allegra)

loratadine (Claritin)

Nursing Implications: Nursing Implications: AntihistaminesAntihistaminesNursing Implications: Nursing Implications: AntihistaminesAntihistamines• Gather data about the condition or allergic reaction that

required treatment; also, assess for drug allergies.

• Contraindicated in the presence of acute asthma attacks and lower respiratory diseases.

• Use with caution in increased intraocular pressure, cardiac or renal disease, hypertension, asthma, COPD, peptic ulcer disease, BPH, or pregnancy.

• Gather data about the condition or allergic reaction that required treatment; also, assess for drug allergies.

• Contraindicated in the presence of acute asthma attacks and lower respiratory diseases.

• Use with caution in increased intraocular pressure, cardiac or renal disease, hypertension, asthma, COPD, peptic ulcer disease, BPH, or pregnancy.

Nursing Implications: Nursing Implications: AntihistaminesAntihistaminesNursing Implications: Nursing Implications: AntihistaminesAntihistamines• Instruct patients to report excessive

sedation, confusion, or hypotension.

• Avoid driving or operating heavy machinery, and do not consume alcohol or other CNS depressants.

• Do not take these medications with other prescribed or OTC medications without checking with prescriber.

• Instruct patients to report excessive sedation, confusion, or hypotension.

• Avoid driving or operating heavy machinery, and do not consume alcohol or other CNS depressants.

• Do not take these medications with other prescribed or OTC medications without checking with prescriber.

Nursing Implications: Nursing Implications: AntihistaminesAntihistaminesNursing Implications: Nursing Implications: AntihistaminesAntihistamines• Best tolerated when taken with meals—

reduces GI upset.

• If dry mouth occurs, teach patient to perform frequent mouth care, chew gum, or suck on hard candy (preferably sugarless) to ease discomfort.

• Monitor for intended therapeutic effects.

• Best tolerated when taken with meals—reduces GI upset.

• If dry mouth occurs, teach patient to perform frequent mouth care, chew gum, or suck on hard candy (preferably sugarless) to ease discomfort.

• Monitor for intended therapeutic effects.

DecongestantsDecongestantsDecongestantsDecongestants

Nasal CongestionNasal CongestionNasal CongestionNasal Congestion

• Excessive nasal secretions

• Inflamed and swollen nasal mucosa

• Primary causes:– Allergies– Upper respiratory infections (common cold)

• Excessive nasal secretions

• Inflamed and swollen nasal mucosa

• Primary causes:– Allergies– Upper respiratory infections (common cold)

DecongestantsDecongestantsDecongestantsDecongestants

Two main types are used:• Adrenergics (largest group)

• Corticosteroids

Two main types are used:• Adrenergics (largest group)

• Corticosteroids

DecongestantsDecongestantsDecongestantsDecongestants

Two dosage forms:• Oral

• Inhaled/topically applied to the nasal membranes

Two dosage forms:• Oral

• Inhaled/topically applied to the nasal membranes

Oral DecongestantsOral DecongestantsOral DecongestantsOral Decongestants

• Prolonged decongestant effects, but delayed onset

• Effect less potent than topical

• No rebound congestion

• Exclusively adrenergics

• Examples: phenylephrine pseudoephedrine (Sudafed)

• Prolonged decongestant effects, but delayed onset

• Effect less potent than topical

• No rebound congestion

• Exclusively adrenergics

• Examples: phenylephrine pseudoephedrine (Sudafed)

Topical Nasal DecongestantsTopical Nasal DecongestantsTopical Nasal DecongestantsTopical Nasal Decongestants

• Both adrenergics and steroids

• Prompt onset

• Potent

• Sustained use over several days causes rebound congestion, making the condition worse

• Both adrenergics and steroids

• Prompt onset

• Potent

• Sustained use over several days causes rebound congestion, making the condition worse

Topical Nasal DecongestantsTopical Nasal DecongestantsTopical Nasal DecongestantsTopical Nasal Decongestants

• Adrenergics:ephedrine (Vicks) naphazoline (Privine)

oxymetazoline (Afrin) phenylephrine (Neo Synephrine)

• Intranasal Steroids:beclomethasone dipropionate (Beconase, Vancenase)

flunisolide (Nasalide)

• Adrenergics:ephedrine (Vicks) naphazoline (Privine)

oxymetazoline (Afrin) phenylephrine (Neo Synephrine)

• Intranasal Steroids:beclomethasone dipropionate (Beconase, Vancenase)

flunisolide (Nasalide)

Nasal Decongestants: Nasal Decongestants: Mechanism of ActionMechanism of ActionNasal Decongestants: Nasal Decongestants: Mechanism of ActionMechanism of ActionSite of action: blood vessels surrounding

nasal sinuses• Adrenergics

– Constrict small blood vessels that supply URI structures

– As a result, these tissues shrink and nasal secretions in the swollen mucous membranes

are better able to drain– Nasal stuffiness is relieved

Site of action: blood vessels surrounding nasal sinuses

• Adrenergics

– Constrict small blood vessels that supply URI structures

– As a result, these tissues shrink and nasal secretions in the swollen mucous membranes

are better able to drain– Nasal stuffiness is relieved

Nasal Decongestants: Nasal Decongestants: Mechanism of ActionMechanism of ActionNasal Decongestants: Nasal Decongestants: Mechanism of ActionMechanism of ActionSite of action: blood vessels surrounding

nasal sinuses• Nasal steroids

– Anti-inflammatory effect– Work to turn off the immune system cells

involved in the inflammatory response– Decreased inflammation results in decreased

congestion– Nasal stuffiness is relieved

Site of action: blood vessels surrounding nasal sinuses

• Nasal steroids

– Anti-inflammatory effect– Work to turn off the immune system cells

involved in the inflammatory response– Decreased inflammation results in decreased

congestion– Nasal stuffiness is relieved

Nasal Decongestants: Drug Nasal Decongestants: Drug EffectsEffectsNasal Decongestants: Drug Nasal Decongestants: Drug EffectsEffects• Shrink engorged nasal mucous membranes

• Relieve nasal stuffiness

• Shrink engorged nasal mucous membranes

• Relieve nasal stuffiness

Nasal Decongestants: Nasal Decongestants: Therapeutic UsesTherapeutic UsesNasal Decongestants: Nasal Decongestants: Therapeutic UsesTherapeutic UsesRelief of nasal congestion associated with:• Acute or chronic rhinitis

• Common cold

• Sinusitis

• Hay fever

• Other allergies

May also be used to reduce swelling of the nasal passage and facilitate visualization of the nasal/pharyngeal membranes before surgery or diagnostic procedures.

Relief of nasal congestion associated with:• Acute or chronic rhinitis

• Common cold

• Sinusitis

• Hay fever

• Other allergies

May also be used to reduce swelling of the nasal passage and facilitate visualization of the nasal/pharyngeal membranes before surgery or diagnostic procedures.

Nasal Decongestants: Side Nasal Decongestants: Side EffectsEffectsNasal Decongestants: Side Nasal Decongestants: Side EffectsEffectsAdrenergics Steroidsnervousness local mucosal dryness

and irritation

insomnia

palpitations

tremors

(systemic effects due to adrenergic stimulation of the heart, blood vessels, and CNS)

Adrenergics Steroidsnervousness local mucosal dryness

and irritation

insomnia

palpitations

tremors

(systemic effects due to adrenergic stimulation of the heart, blood vessels, and CNS)

Nursing Implications: Nursing Implications: Nasal DecongestantsNasal Decongestants

Nursing Implications: Nursing Implications: Nasal DecongestantsNasal Decongestants

• Decongestants may cause hypertension, palpitations, and CNS stimulation—avoid in patients with these conditions.

• Assess for drug allergies.

• Decongestants may cause hypertension, palpitations, and CNS stimulation—avoid in patients with these conditions.

• Assess for drug allergies.

Nursing Implications: Nursing Implications: DecongestantsDecongestantsNursing Implications: Nursing Implications: DecongestantsDecongestants• Patients should avoid caffeine and

caffeine-containing products.

• Report a fever, cough, or other symptoms lasting longer than a week.

• Monitor for intended therapeutic effects.

• Patients should avoid caffeine and caffeine-containing products.

• Report a fever, cough, or other symptoms lasting longer than a week.

• Monitor for intended therapeutic effects.

AntitussivesAntitussivesAntitussivesAntitussives

Cough PhysiologyCough PhysiologyCough PhysiologyCough Physiology

Respiratory secretions and foreign objects are naturally removed by the

• cough reflex– Induces coughing and expectoration– Initiated by irritation of sensory receptors in

the respiratory tract

Respiratory secretions and foreign objects are naturally removed by the

• cough reflex– Induces coughing and expectoration– Initiated by irritation of sensory receptors in

the respiratory tract

Two Basic Types of Cough Two Basic Types of Cough Two Basic Types of Cough Two Basic Types of Cough

• Productive Cough– Congested, removes excessive secretions

• Nonproductive Cough– Dry cough

• Productive Cough– Congested, removes excessive secretions

• Nonproductive Cough– Dry cough

CoughingCoughingCoughingCoughing

Most of the time, coughing is beneficial• Removes excessive secretions

• Removes potentially harmful foreign substances

In some situations, coughing can be harmful, such as after hernia repair surgery

Most of the time, coughing is beneficial• Removes excessive secretions

• Removes potentially harmful foreign substances

In some situations, coughing can be harmful, such as after hernia repair surgery

AntitussivesAntitussivesAntitussivesAntitussives

Drugs used to stop or reduce coughing

• Opioid and nonopioid (narcotic and non-narcotic)

Used only for NONPRODUCTIVE coughs!

Drugs used to stop or reduce coughing

• Opioid and nonopioid (narcotic and non-narcotic)

Used only for NONPRODUCTIVE coughs!

Antitussives: Mechanism of Antitussives: Mechanism of ActionActionAntitussives: Mechanism of Antitussives: Mechanism of ActionActionOpioid• Suppress the cough reflex by direct action on the cough

center in the medulla.

Examples: codeine (Robitussin A-C, Dimetane-DC) hydrocodone

Opioid• Suppress the cough reflex by direct action on the cough

center in the medulla.

Examples: codeine (Robitussin A-C, Dimetane-DC) hydrocodone

Antitussives: Mechanism of Antitussives: Mechanism of ActionActionAntitussives: Mechanism of Antitussives: Mechanism of ActionActionNonopioid• Suppress the cough reflex by numbing the stretch

receptors in the respiratory tract and preventing the cough reflex from being stimulated.

Examples: benzonatate (Tessalon)dextromethorphan (Vicks Formula 44,Robitussin-DM)

Nonopioid• Suppress the cough reflex by numbing the stretch

receptors in the respiratory tract and preventing the cough reflex from being stimulated.

Examples: benzonatate (Tessalon)dextromethorphan (Vicks Formula 44,Robitussin-DM)

Antitussives: Therapeutic Antitussives: Therapeutic UsesUsesAntitussives: Therapeutic Antitussives: Therapeutic UsesUses• Used to stop the cough reflex when the

cough is nonproductive and/or harmful

• Used to stop the cough reflex when the cough is nonproductive and/or harmful

Antitussives: Side EffectsAntitussives: Side EffectsAntitussives: Side EffectsAntitussives: Side Effects

Benzonatate• Dizziness, headache, sedation

Dextromethorphan• Dizziness, drowsiness, nausea

Opioids• Sedation, nausea, vomiting, lightheadedness, constipation

Benzonatate• Dizziness, headache, sedation

Dextromethorphan• Dizziness, drowsiness, nausea

Opioids• Sedation, nausea, vomiting, lightheadedness, constipation

Nursing Implications: Nursing Implications: Antitussive AgentsAntitussive AgentsNursing Implications: Nursing Implications: Antitussive AgentsAntitussive Agents• Perform respiratory and cough assessment,

and assess for allergies.

• Instruct patients to avoid driving or operating heavy equipment due to possible sedation, drowsiness, or dizziness.

• If taking chewable tablets or lozenges, do not drink liquids for 30 to 35 minutes afterward.

• Perform respiratory and cough assessment, and assess for allergies.

• Instruct patients to avoid driving or operating heavy equipment due to possible sedation, drowsiness, or dizziness.

• If taking chewable tablets or lozenges, do not drink liquids for 30 to 35 minutes afterward.

Nursing Implications: Nursing Implications: Antitussive AgentsAntitussive AgentsNursing Implications: Nursing Implications: Antitussive AgentsAntitussive Agents• Report any of the following symptoms to the caregiver:

– Cough that lasts more than a week

– A persistent headache

– Fever

– Rash

• Antitussive agents are for NONPRODUCTIVE coughs.

• Monitor for intended therapeutic effects.

• Report any of the following symptoms to the caregiver:– Cough that lasts more than a week

– A persistent headache

– Fever

– Rash

• Antitussive agents are for NONPRODUCTIVE coughs.

• Monitor for intended therapeutic effects.

ExpectorantsExpectorantsExpectorantsExpectorants

ExpectorantsExpectorantsExpectorantsExpectorants

• Drugs that aid in the expectoration (removal) of mucus

• Reduce the viscosity of secretions

• Disintegrate and thin secretions

• Drugs that aid in the expectoration (removal) of mucus

• Reduce the viscosity of secretions

• Disintegrate and thin secretions

Expectorants: Mechanisms of Expectorants: Mechanisms of ActionActionExpectorants: Mechanisms of Expectorants: Mechanisms of ActionAction• Direct stimulation

or

• Reflex stimulation

Final result: thinner mucus that is easier to remove

• Direct stimulation

or

• Reflex stimulation

Final result: thinner mucus that is easier to remove

Expectorants: Mechanism of Expectorants: Mechanism of ActionActionExpectorants: Mechanism of Expectorants: Mechanism of ActionActionDirect stimulation:• The secretory glands are stimulated directly to increase

their production of respiratory tract fluids.

Examples: terpin hydrate, iodine-containing products such as iodinated glycerol

and potassium iodide (direct and indirect stimulation)

Direct stimulation:• The secretory glands are stimulated directly to increase

their production of respiratory tract fluids.

Examples: terpin hydrate, iodine-containing products such as iodinated glycerol

and potassium iodide (direct and indirect stimulation)

Expectorants: Mechanism of Expectorants: Mechanism of ActionActionExpectorants: Mechanism of Expectorants: Mechanism of ActionActionReflex stimulation:• Agent causes irritation of the GI tract.

• Loosening and thinning of respiratory tract secretions occur in response to this irritation.

Examples: guaifenesin, syrup of ipecac

Reflex stimulation:• Agent causes irritation of the GI tract.

• Loosening and thinning of respiratory tract secretions occur in response to this irritation.

Examples: guaifenesin, syrup of ipecac

Expectorants: Drug EffectsExpectorants: Drug EffectsExpectorants: Drug EffectsExpectorants: Drug Effects

• By loosening and thinning sputum and bronchial secretions, the tendency to cough is indirectly diminished.

• By loosening and thinning sputum and bronchial secretions, the tendency to cough is indirectly diminished.

Expectorants: Therapeutic Expectorants: Therapeutic UsesUsesExpectorants: Therapeutic Expectorants: Therapeutic UsesUsesUsed for the relief of nonproductive coughs

associated with:Common cold Pertussis

Bronchitis Influenza

Laryngitis Measles

Pharyngitis

Coughs caused by chronic paranasal sinusitis

Used for the relief of nonproductive coughs associated with:Common cold Pertussis

Bronchitis Influenza

Laryngitis Measles

Pharyngitis

Coughs caused by chronic paranasal sinusitis

Expectorants: Common Side Expectorants: Common Side EffectsEffectsExpectorants: Common Side Expectorants: Common Side EffectsEffectsguaifenesin terpin hydrateNausea, vomiting Gastric upset

Gastric irritation (Elixir has high alcohol content)

guaifenesin terpin hydrateNausea, vomiting Gastric upset

Gastric irritation (Elixir has high alcohol content)

Nursing Implications: Nursing Implications: ExpectorantsExpectorantsNursing Implications: Nursing Implications: ExpectorantsExpectorants• Expectorants should be used with caution in

the elderly, or those with asthma or respiratory insufficiency.

• Patients taking expectorants should receive more fluids, if permitted, to help loosen and liquefy secretions.

• Report a fever, cough, or other symptoms lasting longer than a week.

• Monitor for intended therapeutic effects.

• Expectorants should be used with caution in the elderly, or those with asthma or respiratory insufficiency.

• Patients taking expectorants should receive more fluids, if permitted, to help loosen and liquefy secretions.

• Report a fever, cough, or other symptoms lasting longer than a week.

• Monitor for intended therapeutic effects.