What is the recommended treatment for cough symptoms associated with influenza (flu)?

Treatment of Cough in Influenza

For cough symptoms associated with influenza, there is no specific cough syrup or antitussive medication recommended by clinical guidelines; instead, focus on symptomatic relief with over-the-counter analgesics (paracetamol or ibuprofen), hydration, rest, and consideration of topical decongestants or throat lozenges, while reserving antiviral therapy (oseltamivir 75 mg twice daily for 5 days) for patients who present within 48 hours of symptom onset and are either at high risk for complications or have severe illness. 1

Symptomatic Management of Cough

There is little scientific evidence supporting specific cough syrups for influenza-related cough. 1 The British Thoracic Society guidelines explicitly state that symptomatic treatment should focus on:

• Paracetamol or ibuprofen for fever, myalgias, and headache (both are equally effective and safe at over-the-counter doses) 1, 2
• Rest and adequate fluid intake 1
• Avoiding smoking 1
• Short course of topical decongestants, throat lozenges, or saline nose drops may be considered 1

The evidence base for these symptomatic treatments is limited, but clinical experience suggests they are unlikely to cause harm and may provide relief. 1 Importantly, there is no evidence that analgesics prolong the course of influenza by suppressing fever or affecting immune function. 2

Critical Pediatric Considerations

Aspirin is absolutely contraindicated in children under 16 years of age with influenza due to the risk of Reye syndrome. 1, 3 For children:

• Use paracetamol or ibuprofen for fever and pain relief 1
• Ensure adequate hydration 1
• Children under 1 year and those at high risk should be assessed by a physician 1

When to Consider Antiviral Therapy

Antiviral therapy with oseltamivir should be considered for cough and other influenza symptoms only if ALL of the following criteria are met: 1, 4

1. Acute influenza-like illness with fever >38°C 1
2. Symptomatic for ≤48 hours (ideally within 24 hours for maximum benefit) 1, 4, 5
3. Either high-risk patient OR severe illness 1, 6

Dosing: Oseltamivir 75 mg orally twice daily for 5 days in adults and adolescents ≥13 years 4. The medication may be taken with food to improve tolerability. 4

High-Risk Groups Warranting Antiviral Treatment

The following patients should be prioritized for antiviral therapy: 6

• Adults ≥65 years of age 6
• Children <2 years of age 6
• Pregnant women and postpartum women within 2 weeks of delivery 6
• Immunocompromised patients (who may not mount adequate fever and can still receive antivirals despite lack of documented fever) 1, 6
• Patients with chronic cardiac, pulmonary, renal, or metabolic disease 1, 6

Important caveat: Patients who are immunocompromised or very elderly may not develop fever but can still benefit from antiviral treatment. 1

What Antiviral Therapy Actually Achieves

Realistic expectations are crucial. In otherwise healthy adults and children, oseltamivir shortens the duration of illness by approximately 1 day when started within 48 hours of symptom onset. 4, 7, 5 The primary benefit is reducing symptom duration by about 24 hours, not eliminating the cough immediately. 5

For high-risk patients, while the effect on symptom duration may be less pronounced, antivirals may reduce the risk of serious complications such as pneumonia, though this has not been definitively proven in all populations. 7, 5

When Antibiotics Are NOT Indicated

Do not prescribe antibiotics for uncomplicated influenza with cough in the absence of bacterial co-infection. 1, 3, 8 Previously well adults with acute bronchitis complicating influenza do not routinely require antibiotics. 1

Consider antibiotics only when: 1, 3

• Previously well patients develop worsening symptoms (recrudescent fever or increasing dyspnea) 1
• High-risk patients develop lower respiratory tract features suggesting pneumonia 1
• Confirmed or suspected influenza-related pneumonia (requires immediate antibiotic therapy within 4 hours of diagnosis) 1, 3

Red Flags Requiring Re-consultation

Patients should be instructed to seek immediate medical attention if they develop: 1

• Shortness of breath at rest or with minimal activity 1
• Painful or difficult breathing 1
• Coughing up bloody sputum 1
• Drowsiness, disorientation, or confusion 1
• Fever persisting 4-5 days without improvement or worsening 1
• Initial improvement followed by recurrent high fever 1
• No improvement within 48 hours of starting oseltamivir 1

Common Pitfalls to Avoid

Do not prescribe cough suppressants or specific "cough syrups" as primary treatment for influenza-related cough – the guidelines do not support their use and there is insufficient evidence for their efficacy. 1 The focus should be on general supportive care and determining whether antiviral therapy is indicated.

Do not delay antiviral treatment while awaiting laboratory confirmation if the patient meets clinical criteria and presents within the treatment window. 3 Clinical diagnosis is sufficient during influenza season when the virus is circulating in the community. 1

Do not use oseltamivir in patients with end-stage renal disease not undergoing dialysis without dose adjustment; reduce dose to 75 mg once daily if creatinine clearance is <30 mL/min. 4