Cough

Initiation of cough

- Stimulation of chemically and mechanically sensitive, vagally mediated bronchopulmonary and extrapulmonary sensory nerves in the upper and lower respiratory tract

Complications of a cough

- Exhaustion, sleep deprivation, musculoskeletal pain, hoarseness, excessive perspiration, social embarrassment, and urinary incontinence

Purpose of antitussives

- Control or eliminate cough

When are antitussives used?

Nonproductive cough

Purpose of protussives

Change the consistency and volume of mucus and may make it easier to expel thick, tenacious secretions

When are protussives used?

Productive cough

Why should you not use antitussives and protussives together?

- Counterproductive and unnecessary active ingredients contribute to increased risk for avoidable adverse effects and drug interactions

Products with little evidence for use to treat coughs

- Menthol

- Camphor

- Volatile oils

If a cough persists for more than 7 days but has lessened in severity, what should a patient do?

Continue self-treatment regimen until the cough resolves

How long for coughs to improve after viral upper respiratory tract infection

- Usually 2 weeks but can take 3 weeks or longer

How long for coughs to improve that are associated with other respiratory infections

3-4 weeks

Duration of acute cough

<3 weeks

Etiology of acute cough

- Viral upper respiratory tract infection

- Acute bronchitis

- Pertussis

- Acute rhinitis

- Aspiration syndromes

- Asthma/COPD exacerbations

- Pneumonia

- Pulmonary embolism

- Acute left ventricular failure

Duration of subacute cough

3-8 weeks

Etiology of subacute cough

- Postinfectious cough

- Bacterial sinusitis

Duration of chronic cough

>8 weeks

Etiology of chronic cough

- Upper airway cough syndrome

- GERD

- COPD

- Chronic bronchitis

- ACE inhibitors

- Cancer

- Sarcidosis

- Chronic left ventricular failure

- Aspiration secondary to pharyngeal dysfunction

Primary treatment goal for cough

Reduce the number and severity of cough episodes

Secondary treatment goal for coughs

Prevent complications

Exclusion criteria: Temperature from ______ to ______ for ________ or more days

100-100.3 for 4 or more days

Exclusion criteria: Temperature of _______ or higher (rectal)

100.4

Exclusion criteria for age

<4 years old

Exclusion criteria specifically related to cough symptoms and duration

- Cough that worsens after 3-5 days

- Cough that does not improve after 2-3 weeks

- Barking cough with inspiratory stridor (croup)

- Severe coughing spells that end with a whooping sound during inspiration

- Cough that begins suddenly without fever or upper respiratory infection symptoms

Exclusion criteria related to illnesses

- Immunocompromised status

- Risk factors for HIV infection (high-risk sexual activities, use of injectable street drugs)

- Chronic illness (asthma, COPD, CHF, diabetes mellitus, sickle cell anemia)

- History of exposure to tuberculosis

Exclusion criteria related to symptoms

- Difficulty breathing, SOB

- Cyanosis (blue skin)

- Hemoptysis (coughing up blood)

- Weight loss

- Night sweats

Description of productive cough

Wet or chesty

Physiological purpose of productive coughs

- Expel secretions from the lower respiratory tract that, if retained, could impair ventilation and the lungs' ability to resist infection

Effective productive cough definition

Secretions easily expelled

Ineffective productive cough definition

- Secretions present but difficult to expel

What are clear secretions often associated with?

- Bronchitis

- Bacterial infections

Description of nonproductive cough

- Dry or hacking

Physiological purpose of nonproductive cough

None

What are nonproductive coughs associated with?

Viral and atypical bacterial infections, GERD, cardiac disease, and some meds (ACE inhibitors)

Symptoms of acute cough associated with the common cold

- Cough with or without mucus associated with upper respiratory illness (nasal congestion, runny nose)

Treatment strategies for acute cough associated with the common cold

Non-drug measures

Symptoms of upper airway cough syndrome

- Dry cough persisting after a viral upper respiratory illness with symptoms such as tickle in throat and frequent throat clearing

Treatment strategies for upper airway cough syndrome

- Non-drug measures

- Frist generation antihistamine

- Decongestant

Non-pharmacologic treatment options for cough

- Non-medicated lozenges and hard candies

- Humidification

- Hydration

What type of humidifiers and vaporizers are preferred?

Cool-mist

Nonpharmacologic treatment options for cough in <2 years old

- Rubber bulb nasal syringe to clear nasal passages and reduce cough

- Prop infant upright when they sleep and raise the head of the bed at night to promote drainage of nasal secretions

Dextromethorphan uses

- Suppression of nonproductive cough caused by chemical or mechanical respiratory tract irritation

- Recommended for short-term symptomatic relief of cough associated with acute and chronic bronchitis and postinfectious subacute cough

Dextromethorpham MOA

- Acts centrally in the medulla to increase the cough threshold

Dextromethorpan special populations

- Probably safe during pregnancy

- Unknown whether excreted in breastmilk

- Older adults should use lower doses

Dextromethorphan side effects

- Uncommon but drowsiness, N/V, stomach discomfort, constipation

- Robo-tripping can result in euphoric manifestations

Dextromethorphan DDIs

- Alcohol

- SSRIs and MAOIs

Guaifenesin indications

- Symptomatic relief of acute, ineffective productive cough

- Generally not recommended unless patient requests a product to provide relief of a productive cough

Guaifenesin MOA

- Loosens and thins lower respiratory tract secretions, making minimally productive cough more productive

Guaifenesin side effects

- Uncommon but N/V, dizziness, headache, rash, diarrhea, drowsiness, and stomach pain

Diphenhydramine indications

- Suppression of nonproductive cough caused by chemical or mechanical respiratory tract irritation

Diphenhydramine MOA

First generation antihistamine that acts centrally to raise the cough threshold

Diphenhydramine special populations

- Common in pregnancy

- Excreted in breastmilk and may lead to unusual excitation and irritability in infants and decrease flow of milk

- Elderly are more likely to experience anticholinergic effects

Diphenhydramine common side effects

- Drowsiness, disturbed coordination, respiratory depression, blurred vision

Diphenhydramine uncommon side effects

- Excitability among children, acute dystonic reactions, allergic reactions

Diphenhydramine precautions

- Patients with narrow angle glaucoma, urinary difficulties, asthma, COPD, elevated IOP, hyperthyroidism, hypertension, and cardiovascular disease

Diphenhydramine DDIs

- Opioid analgesics (consider dose reduction)

- Potassium chloride (avoid concurrent use)

Menthol and Camphor uses

Objective evidence is limited

Menthol and Camphor MOA

- Stimulate sensory nerve endings within the nose and mucosa, creating a local anesthetic sensation and sense of improved airflow

- Cough reflex sensitivity may be suppressed

Menthol and Camphor special populations

- Can use in children >=2 years old but there are concerns about toxicity

- Use caution with lozenges (choking hazard)

Menthol and camphor side effects

- Skin, nose, or eye burning/irritation

- Toxic if ingested (burning sensation in mouth)

Menthol DDIs

- Cough drops

- Warfarin

Volatile oils indication

- Strong medicinal odor but not FDA approved as antitussive

Volatile oils side effects

Hypersensitivity reactions

Administration of ointments

- Rub on the throat and chest in a thick layer

- Can repeat application up to tid prn or as directed by PCP

- Loosen clothing around throat and chest

- Do not use in the nostrils, under the nose, by the mouth, on damaged skin, or with tight bandages

Administration of lozenges

- Allow lozenge to dissolve slowly in mouth

- Repeat hourly or as needed or directed by PCP

Administration of inhalation

- Measure solution

- Place the mixture in the vaporizer or chamber

- Breathe in the medicinal vapors up to tid prn