What is the best course of treatment for a 10-week pregnant patient with a persistent dry cough for 3 weeks without any other symptoms?

Management of 3-Week Dry Cough in 10-Week Pregnancy

For this pregnant patient with a 3-week dry cough and no other symptoms, the most appropriate initial treatment is inhaled ipratropium bromide, as this represents postinfectious cough and ipratropium is the only evidence-based first-line therapy with demonstrated efficacy in attenuating subacute postinfectious cough. 1, 2

Diagnostic Classification

• This is a subacute postinfectious cough (3-8 weeks duration following a presumed viral respiratory infection), which is the most common cause of cough in this timeframe 1, 2
• The absence of other symptoms makes serious pathology less likely, but certain red flags must be excluded 2

Critical Red Flags to Exclude First

Before initiating treatment, assess for the following urgent conditions:

• Vital sign abnormalities: Heart rate ≥100 bpm, respiratory rate ≥24 breaths/min, temperature ≥38°C 2
• Asymmetrical lung sounds or focal consolidation on examination 2
• Pertussis features: Paroxysmal coughing episodes, post-tussive vomiting, or inspiratory whooping sound 1, 2
• Hemoptysis or systemic symptoms (fever, weight loss, night sweats) 2

If any red flags are present, obtain a chest X-ray immediately 2. If pertussis is suspected, start azithromycin immediately and obtain nasopharyngeal culture 1, 3.

Evidence-Based Treatment Algorithm

First-Line Therapy

• Inhaled ipratropium bromide is the only medication with fair-quality evidence demonstrating efficacy in attenuating postinfectious cough 1, 2
• This is the recommended first-line treatment for subacute postinfectious cough 2, 3
• Antibiotics have no role in postinfectious cough, as the cause is not bacterial infection 1, 3

Second-Line Options (If Ipratropium Fails)

• Dextromethorphan can be considered for dry, bothersome cough, particularly when disrupting sleep 4
• However, dextromethorphan should be used cautiously in pregnancy - the FDA label states "if pregnant or breast-feeding, ask a health professional before use" 5
• Inhaled corticosteroids may be considered if cough persists despite ipratropium and adversely affects quality of life 1

Pregnancy-Specific Considerations

• Albuterol is the preferred short-acting beta-agonist if bronchospasm is suspected, as it has the most safety data in pregnancy 1
• Budesonide is the preferred inhaled corticosteroid if ICS therapy becomes necessary, as it has the most reassuring pregnancy safety data 1
• Avoid systemic corticosteroids unless severe paroxysms occur and other common causes (upper airway cough syndrome, asthma, GERD) have been ruled out 1

Important Pitfalls to Avoid

• Do not prescribe antibiotics for viral postinfectious cough - this provides no benefit and contributes to antibiotic resistance 4, 3
• Do not assume GERD without typical symptoms (heartburn, sour taste, regurgitation) - empiric PPI therapy is not recommended 4
• Do not use long-term macrolides (azithromycin, erythromycin) for chronic cough suppression - they are ineffective for this indication 4

Follow-Up Strategy

• Provide reassurance that postinfectious cough typically resolves spontaneously within 3-8 weeks from symptom onset 3
• Schedule follow-up in 4-6 weeks to reassess 2
• If cough persists beyond 8 weeks total, reclassify as chronic cough and initiate systematic evaluation for upper airway cough syndrome, asthma, and GERD 2, 3

Special Consideration for Pertussis

Given the pregnancy status and potential exposure risks:

• Maintain high suspicion for pertussis even without classic whooping sound, as it can present atypically 1
• If pertussis is confirmed or highly suspected, macrolide antibiotics are indicated for treatment and preventing transmission (not for cough suppression) 1, 3
• Early treatment within the first few weeks diminishes coughing paroxysms and prevents disease spread 1