What are the recommended cough medications for dry versus productive coughs, considering patient age, comorbidities, and contraindications?

Cough Medication: Evidence-Based Recommendations

Acute Cough (< 3–4 weeks)

For acute cough in adults and children, over-the-counter cough medications provide no proven benefit and should not be used. 1

• Acute cough is most commonly viral and self-limiting, requiring only supportive care 1
• Patients report subjective benefit from OTC preparations, but there is little evidence of specific pharmacological effect 1
• Do not give over-the-counter cough or cold medications to children—they provide no therapeutic benefit and may cause harm 2
• Antibiotics are not indicated for acute viral cough lasting < 4 weeks without signs of bacterial infection 3

When to Investigate Acute Cough Further

Pursue further workup if any of the following are present:

• Hemoptysis 1
• Prominent systemic illness 1
• Suspicion of inhaled foreign body 1
• Suspicion of lung cancer 1

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Chronic Cough in Adults (> 8 weeks)

Initial Evaluation

All adults with chronic cough require chest radiograph and spirometry as mandatory first steps. 1

• Most chronic cough in adults results from upper airway cough syndrome (postnasal drip), asthma, gastroesophageal reflux disease, or nonasthmatic eosinophilic bronchitis 1, 4, 5
• These four conditions account for 90% of chronic cough cases 5
• The character, timing, and complications of cough do not reliably predict the underlying cause 5

Treatment Algorithm for Adults

1. Stop ACE inhibitors immediately if the patient is taking one—cough is unlikely to be corticosteroid-responsive if it persists after ACE inhibitor cessation. 1

2. For suspected asthma or eosinophilic bronchitis:

• Trial of inhaled corticosteroids (400 mcg/day budesonide equivalent) for 2 weeks 1
• If no response after 2 weeks of oral steroids, cough is unlikely due to eosinophilic airway inflammation 1

3. For suspected GERD:

• Proton pump inhibitor (omeprazole 40 mg daily or equivalent) plus dietary modification and lifestyle changes 1
• Add prokinetic therapy (metoclopramide 10 mg four times daily) if PPI alone is ineffective 1
• Treatment may take 8 weeks or longer to show benefit; some patients require months 1

4. For refractory chronic cough (failed empiric trials):

• Low-dose morphine is highly effective in a subset of patients with cough resistant to other treatments 6
• Gabapentin or pregabalin can be tried, though limited by adverse events 6, 4
• Dextromethorphan: effect size 0.37 for cough severity (95% CI 0.19–0.56, P = 0.0008) 7
• Opioid antitussives: effect size 0.55 for cough severity (95% CI 0.38–0.72, P < 0.0001) 7
• Speech therapy/cough suppression therapy when performed by competent practitioners 6

Benzonatate (FDA-Approved Antitussive)

For adults and children over 10 years: 100–200 mg three times daily as needed; maximum 600 mg daily in three divided doses 8

Critical safety warning: Benzonatate capsules must be swallowed whole—never broken, chewed, dissolved, cut, or crushed 8

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Chronic Cough in Children (> 4 weeks)

Initial Classification

First, determine whether the cough is wet/productive or dry/non-productive—this distinction drives all subsequent management. 9

• Wet/productive cough suggests protracted bacterial bronchitis, bronchiectasis, or chronic suppurative lung disease 9
• Dry/non-productive cough may represent post-viral cough, asthma, or non-specific cough 9

Mandatory Initial Investigations

Obtain chest radiograph and spirometry (if child ≥ 3–6 years old) for all children with chronic cough. 1, 9

Red Flags ("Specific Cough Pointers")

Immediate further investigation required if any of the following are present:

• Coughing with feeding 1, 9
• Digital clubbing 1, 9
• Hemoptysis 9
• Failure to thrive 1
• Abnormal chest radiograph or spirometry 1, 9

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Management Algorithm for Wet/Productive Cough in Children

1. First-line treatment (no specific pointers present):

• Prescribe 2 weeks of antibiotics targeting Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis based on local antibiotic sensitivities 1
• Amoxicillin-clavulanate is the most commonly used regimen 3
• If cough resolves within 2 weeks, diagnose protracted bacterial bronchitis (PBB) 1

2. If cough persists after 2 weeks:

• Extend antibiotics for an additional 2 weeks 1, 3

3. If cough persists after 4 weeks total:

• Proceed to further investigations: flexible bronchoscopy with quantitative cultures, chest CT, assessment for aspiration, evaluation of immunologic competency 1, 9
• Refer to pediatric pulmonology 9

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Management Algorithm for Dry/Non-Productive Cough in Children

1. Initial approach (no specific pointers present):

• Adopt a "watch, wait, and review" strategy—most cases are post-viral and resolve spontaneously 1, 9
• Review in 2–4 weeks to assess for resolution or development of specific pointers 9

2. Do NOT empirically treat for asthma unless:

• Cough worsens at night 2
• Episodes triggered by exercise or irritants 2
• Family history of asthma or atopy 2
• Other features consistent with asthma are present 9

3. If empirical trial of inhaled corticosteroids is warranted:

• Use 400 mcg/day budesonide equivalent for 2–3 weeks 1
• If no response, cease ICS and reconsider diagnosis 1, 9

4. If dry cough persists > 4 weeks:

• Perform systematic evaluation for chronic cough with chest radiograph and spirometry 9
• Consider flexible bronchoscopy if severe, persistent, or atypical presentation—68% of such infants have associated lower airway abnormalities 2

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Environmental and Supportive Measures

Eliminate tobacco smoke exposure—this is a major contributor to chronic cough in both adults and children. 9, 10

• Ensure adequate hydration to thin secretions and facilitate clearance 9
• Avoid chest physiotherapy—it offers no benefit and may cause harm 2
• Antipyretics can be used for comfort in febrile children 2

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Critical Pitfalls to Avoid

• Never use combination cough preparations—they should not be prescribed 10
• Never give OTC cough medications to children—they lack proven efficacy and carry risk of serious adverse effects 2, 9
• Never give antihistamines or decongestants for cough—they are ineffective and carry potential adverse effects 2
• Never use honey for acute cough—it is only helpful for post-viral cough, not inflammatory airway conditions 2
• Never empirically treat for GERD, asthma, or upper airway cough syndrome without specific clinical features supporting these diagnoses 9
• Never discharge a child within 2 hours of nebulized epinephrine (if given for croup-like presentation) due to risk of rebound symptoms 2