What is the recommended treatment for a patient with an unspecified medical condition and cough?

Treatment of Cough: Evidence-Based Approach

The treatment of cough must be guided by determining whether it is acute (< 3 weeks), subacute (3-8 weeks), or chronic (> 8 weeks), and then systematically addressing the underlying cause rather than simply suppressing the symptom. 1, 2

Initial Diagnostic Evaluation

Before initiating any treatment, perform the following assessments:

• Obtain a chest radiograph to exclude serious pathology including pneumonia, malignancy, or structural lung disease 2
• Review medication list for ACE inhibitors, which are a common cause of persistent dry cough and should be discontinued 1, 2
• Assess smoking status - if the patient smokes, advise cessation as this alone can resolve cough within 4 weeks 2
• Perform spirometry to identify airway obstruction or asthma 2

Treatment Algorithm Based on Cough Duration

Acute Cough (< 3 weeks)

• First determine if the cough reflects a serious illness such as pneumonia or pulmonary embolism versus a non-life-threatening condition like common cold or lower respiratory tract infection 1
• For symptomatic relief in acute cough, dextromethorphan is FDA-approved as a cough suppressant 3, though evidence for OTC medications is limited 4, 5
• Do not use dextromethorphan if the patient is taking an MAOI or has taken one within the past 2 weeks 3
• Avoid use if cough is productive with excessive phlegm, or associated with chronic conditions like smoking, asthma, or emphysema 3

Subacute Cough (3-8 weeks)

• Determine if this is postinfectious cough or related to upper airway cough syndrome, transient bronchial hyperresponsiveness, asthma, pertussis, or acute exacerbation of chronic bronchitis 1
• If noninfectious, manage as chronic cough (see below) 1

Chronic Cough (> 8 weeks)

The most common causes must be systematically evaluated and treated in sequence: 1, 2

First-Line Treatments for Common Causes:

1. Upper Airway Cough Syndrome (most common cause in adults)

   • Treat with first-generation antihistamine/decongestant combinations, not opioids 6, 2
   • This is the most common cause and should be addressed first 6

2. Asthma/Eosinophilic Bronchitis

   • Test for bronchial hyperresponsiveness, sputum eosinophils, and exhaled nitric oxide 6
   • Initiate inhaled corticosteroids combined with bronchodilators 2
   • Consider oral prednisone (30-40 mg daily for a short period) for severe cough when other causes ruled out 2

3. Gastroesophageal Reflux Disease (GERD)

   • Initiate empiric proton pump inhibitor therapy if cough persists after addressing upper airway cough syndrome and asthma 2
   • However, for patients with idiopathic pulmonary fibrosis and negative workup for acid reflux, do not prescribe proton pump inhibitors 1

4. Drug-Induced Cough

   • Evaluate all medications as potential causes 1
   • Consider a therapeutic trial of withdrawing the suspected drug 1

Management of Refractory/Unexplained Chronic Cough

Unexplained chronic cough is a diagnosis of exclusion and should only be made after thorough evaluation, specific treatment trials have failed, and uncommon causes have been ruled out 1, 6

Before Diagnosing as Unexplained:

• Perform chest CT scan and, if necessary, bronchoscopic evaluation if cough persists after consideration of common causes 1
• Ensure objective testing for bronchial hyperresponsiveness and eosinophilic bronchitis has been completed, or a therapeutic corticosteroid trial has been attempted 6

Treatment Options for Truly Refractory Cough:

1. Multimodality speech pathology therapy (Grade 2C recommendation)

   • Includes cough suppression techniques, vocal hygiene, and psychoeducational counseling 1, 6, 2

2. Gabapentin trial

   • Begin at 300 mg once daily, escalate up to maximum 1,800 mg daily in two divided doses 6
   • Discuss potential side effects and risk-benefit profile before initiating 6
   • Reassess risk-benefit profile at 6 months before continuing 6

3. Opiates (last resort)

   • Only recommend when all alternative treatments have failed and cough adversely affects quality of life 1, 6
   • Use in palliative care setting with reassessment of benefits and risks at 1 week, then monthly 1
   • Codeine and morphine are effective but produce side effects including drowsiness, nausea, constipation, and physical dependence 7, 8

Special Populations

Interstitial Lung Disease (ILD)

• Assess for progression of underlying ILD or complications from immunosuppressive treatment (e.g., drug side effects, pulmonary infection) 1
• For pulmonary sarcoidosis, do not routinely prescribe inhaled corticosteroids to treat chronic cough (Grade 2C) 1
• For ILD with refractory chronic cough, follow unexplained chronic cough guidelines with gabapentin and speech pathology therapy 1

Patients with Dysphagia

• Perform videofluoroscopic swallow evaluation or fiberoptic endoscopic evaluation of swallowing 2
• Manage with organized multidisciplinary teams 2

Critical Pitfalls to Avoid

• Do not rely solely on cough characteristics for diagnosis - they have limited diagnostic value 2
• Do not treat only one potential cause - multiple factors often contribute to chronic cough 2
• Do not continue symptomatic opioid treatment without addressing the underlying cause 6
• Do not prescribe antibiotics for postinfectious cough unless there is evidence of bacterial infection 2
• Stop dextromethorphan and seek medical attention if cough lasts more than 7 days, returns, or occurs with fever, rash, or persistent headache - these could indicate a serious condition 3

When to Refer to Specialist

• Cough persists despite sequential trials of therapy for common causes 2
• Diagnosis remains unclear after basic investigations 2
• Significant comorbidities complicate management 2
• Cough severely impacts quality of life despite appropriate treatment 2