Acute cough Flashcards
what is acute cough
- caused by many resp diseases, aim is to protect resp tract
- voluntary or involintarily activated reflex arc
- triggered by chemical or mechanical stimuli
how is cough stimulated
- receptors in head, neck and chest are stimulated
- information transmitted to cough centre in medulla via afferent limb of vagus nerve
- get increased neural activity in efferent pathway to moth repsiratory musculature and airway
what are the 3 categories of acute cough
acute (lasting <3 weeks)
subacute (lasting 3–8 weeks)
chronic (lasting >8 weeks)
what is the most common cause of acute cough
viral ifnections of upper respiratory tract
*coughs can persist after infection (postinfectious)
what causes a cough in viral infections
arises from stimulation of cough relfex in upper resp tract caused by postnasal drip, cleaing or throat or both
what is an indication of a Bordetella pertussis or B. parapertussis infection
patients with subacute or chronic cough
or when the cough is paroxysmal or accompanied by vomiting
*refer
when to refer for acute cough
if breathing is compromised
high fever
seizures
frequent vomiting episodes
or the patient becomes dehydrated.
what are common causes of cough
Asthma
Chronic obstructive pulmonary disease
Drugs, e.g., ACE inhibitors, beta-blockers, ASA or NSAIDs in sensitive individuals
Environmental/occupational irritants, e.g., air pollution, cigarette smoke, asbestos
Foreign body
Gastroesophageal reflux disease
Heart failure
Pulmonary embolism
Rhinitis: allergic, nonallergic
Sinusitis
Upper airway cough syndrome (formerly postnasal drip syndrome)
Upper/lower respiratory tract infection (viral or bacterial): acute or postinfectious
what are less common causes of cough
Bronchiectasis
Cystic fibrosis
Interstitial lung disease
Lung cancer
Psychogenic cough
Unexplained cough (idiopathic)
Zenker diverticulum (esophageal pouch)
what are the goals of therapy for treatment of acute cough
Alleviate symptoms
Diagnose and treat underlying cause, when possible
Prevent complications
non pharmacologic therapy for treatment of acute cough
- not sufficient evidence but hydration w/ oralliquids and humidification of room air can be beneficial
* Room humidifiers used as preventive measures should be well cleaned to avoid aerosolizing mould
- nasa saline irrigation may help to relieve symptoms of nasal congestion
*Avoid exposure to inhaled irritants such as smoke, dust, pollutants and allergens.
treatment for viral respiratory infection
- no cure
- despite lack of evidence many use nonspecific treatments like nonprescription antitussives and protussives (expectorant) depending on mucus
- do not recommend tho bc lack of evidence
evidence for non prescription cough medication
lac of evidence for or against
- probably mostly placebo
antihistamines for treatment of acute cough
- First generation
- small effect on cough caused by upper respiratroy tract infections
- anticholinergic properties can reduce postnasal drop (mechanism resposibe for cough in common cold)
- effect is modest
- side effect” drowsiness, dry mouth and confusion
- NOT recommended until more evidence comes out
- Second generation
- lack significant anticholinergic efects
- not effective for acute cough treatment unless secondary to allergic rhinitis
antitussive for treatment of acute cough
- act centrally to supress cough
exact mechanism not known -> thought to involve brainstem
- not recommended when cough performs a useful function, then are retaining mucus you dont want to be
Dextromethorphan and codeine for treatment of acute cough
- commonly used to treat cough related to upper respiratory tract infections
*little evidence for efficacy
- some studies show no more effective than placebo
*extromethorphan has been abused for its euphoric properties, while codeine carries a risk of dependence and addiction
* not recommend centrally acting cough suppressants for cough secondary to upper respiratory tract infections.
- effective for cough due to COPD, supressing cough counts be 40-60%, can use for short term relief
example of expectorant for treatment of acute coughGuaifenesin
Guaifenesin
use of expectorants to treat acute cough
- protussive agents act peripherally
- ex: Guaifenesin (shown to enhance cough effectiveness by clearing airway secretions), guaiacol and ammonium chloride (efficacy & safety not established
- act by reduce sputum viscosity, permitting more effective removal of secretions from the respiratory tract
- lack of evidence to support efficacy -> do not thin sputum nor increase sputum volume
- Adequate hydration with oral liquids and inhalation of humidified air is perhaps the best protussive or “expectorant” measure.
Honey for treatment of acute cough
- can be effecive cough supressant in children
- no studies in adults available
*Cochrane review concluded that honey administered before sleep is probably better than no treatment, placebo or diphenhydramine, and no different from dextromethorphan, at relieving cough symptoms.
- has demulcent, antioxidant and antibacterial effects
- > demulcent effect may act to decrease cough
* risk of botulism, only give to immunocompetent children >1 year of age
zinc lozenges for treatment of acute cough
- used to alleviate cough due to the common cold
- studies show conflicitng results, overall insufficient evidence to recomend sin preparations
* zing can also be associated with unpleasant taste, mouth irritation and nausea.
anesthetics for treatment of acute cough
ex benzocaine, phenol and menthol
- may reduce sensitivity of peripheral nociceptors
- have been used as antitussives but evidence for efficacy is poor
NSAIDs for treatment of acute cough
Inflammatory pathways have been largely investigated to play a role in the pathophysiology of cough
hNSAIDs were found to have no effect on cough symptoms.
prescription therapy for cough
salbutamol or formotero
onky recommended for cough due to obstructive lung disease like asthma or COPD.
*Following a respiratory infection, patients sometimes develop a cough for which inhaled corticosteroids could be beneficial; the potential benefit of inhaled corticosteroids requires confirmation through further studies before making recommendations for their routine use.
cough can be secondary to another medical condiiton, treat unerlying cause:
Allergic Rhinitis and Viral Rhinitis, Influenza, Sinusitis and Pharyngitis, Acute Bronchitis
treating cough in children
- little evidence supporting use
- HC advises against use of products in children <6 due to rare serious side effects, misue and overdose
wht prescription medication can you give to kids >6 for treatment of cough
dextromethorphan
- evidence of efficacy in children is abdent but can b e uses to treat unproductive cough
-
how should therapy for cough be monitored
- Cough
- patient to monitor daily, HC practitioner: next visit or by phone 2-3 days later
- endpoint of therapy: patient can perform daily activites and able to sleep
- if endpoint not met: change treatment or optimize non pharm measures
- Drowsiness (antitussives)
- patient to monitor daily, HCP: next visit or by phone when checking for efficacy
- endpoint therapy: no drowsiness
- if endpoint not met: change medication schedule (bedtime only) or change treatment
cough treatment with codine
dose
adverse effects
drug interactions
comments
- dose
- Adult: 10-20mg Q4-6H
- Max: 120 mg/day
- *HC recommends against use for children <18
- Adverse effects
- drowsiness, sedation, N/V, constipation
- Drug interactions
- CNS depressants (alc) can enhance CNS side effects
- MAIOs: risk serotonin syndrome
- CYP2D6 inhibitors (fluoxetine, paroxetine) can inhibit conversion of codeine to active metabolite -> reduce clinical effect
- COmments
- causes less sedation then hydrocodone
- metabolize to morphine
- dependece/addiciton potential
treatment of cough with dextromethorphan
dose
adverse effects
drug interactions
comments
- Dose
- Adults & chidlren >12:
- 10-20 mg Q4H PO OR 30mg Q6-8H
- max 120mg/day
- Children 6-11
- 5-10 mg Q4H or 15 mg Q6-8H
- Max 60 mg.day
- Adults & chidlren >12:
- Adverse efects
- generally well tolerated
- occasional diziness, drowsiness, nausea
- Drug interactions
- modulators of serotonin: risk or serotonin sydrone
- ex: SSRIs
- CYP2D6 inhibitors
- modulators of serotonin: risk or serotonin sydrone
- Comments
- causes less sedation then codeine and other opioids
- has ben abused bc of euphoric effects
treatment of cough with honey
dose
adverse reactions
interactions
comments
- Dose
- Adults: 15 mL dailt TID
- Children 1-18: 2.5-10 mL HS
- Side efects
- rare: nervousness, insomnia, hyperactivity
- Interactions
- none known
- Comments
- use pasteuized due to botulism risk
- avoid in children <1 or immunocompromized patients
- avodi if allergic to pollen
treatment of cough with guaifenesin
dose
side effect
interactions
- Dose
- adults and children >12
- 200-400mg Q4H
- Max 2.4 g/day
- Children >6
- 12mg/kg/day
- divided doses Q4H
- max 1.2g/day
- adults and children >12
- Side effects
- rare: dizziness, drowsiness, headache, nausea and vomiting (reported at high doses)
- Interactions
- none known
