What is the recommended treatment for an elderly patient presenting with influenza (flu) symptoms, potentially with underlying conditions such as chronic obstructive pulmonary disease (COPD) or heart disease?

Treatment of Influenza in Elderly Patients

Initiate oseltamivir 75 mg orally twice daily for 5 days immediately in elderly patients presenting with influenza symptoms, regardless of underlying conditions such as COPD or heart disease. 1, 2

Immediate Antiviral Therapy

• Start oseltamivir 75 mg orally twice daily for 5 days if the patient presents with acute influenza-like illness, fever >38°C, and symptoms within 48 hours of onset. 3
• Elderly patients (≥65 years) are at high risk for complications and should receive antiviral treatment promptly. 3
• Oseltamivir reduces mortality by 18% in older adults hospitalized with influenza, even when initiated after 48 hours. 4
• Earlier initiation is associated with faster resolution: treatment started within 0-12 hours results in mean fever duration of 26-38 hours, compared to 54 hours when started at 13-24 hours. 5
• Oseltamivir reduces illness duration by 24-53.9 hours and symptom severity by up to 38%. 1, 6

Dose Adjustments for Renal Impairment

• Reduce oseltamivir dose to 75 mg once daily if creatinine clearance is <30 mL/min. 1, 2, 7
• No dose adjustment is needed for mild to moderate hepatic impairment. 7

Management of Underlying Conditions

For Patients with COPD or Chronic Respiratory Disease:

• Administer oseltamivir PLUS systemic corticosteroids (prednisone 40 mg daily for 5 days), short-acting bronchodilators, and antibiotics. 2
• Oseltamivir significantly reduces acute febrile illness duration in patients with chronic obstructive airways disease (37.9 hours vs 53.8 hours with placebo, p=0.004). 8
• Treat worsening comorbid illnesses according to disease-specific guidelines. 3

For Patients with Chronic Cardiac Disease:

• Oseltamivir reduces median duration of acute febrile illness in cardiac disease patients (44.0 hours vs 64.7 hours with placebo, p=0.026). 8

Severity Assessment and Hospital Admission Criteria

• Calculate CURB-65 score immediately upon presentation. 3
  • Score 1 point each for: Confusion, Urea >7 mmol/L, Respiratory rate ≥30/min, Blood pressure (SBP <90 or DBP ≤60 mmHg), Age ≥65 years
• CURB-65 score 0-1: Consider home treatment 3
• CURB-65 score 2: Consider short inpatient stay or hospital-supervised outpatient management 3
• CURB-65 score ≥3 or bilateral lung shadows on chest x-ray: Manage in hospital as severe pneumonia 3

Oxygen Therapy

• Maintain SpO2 ≥92% with supplemental oxygen if needed. 1, 2
• For patients with known COPD and potential CO2 retention, use controlled oxygen therapy with repeated arterial blood gas monitoring. 1, 2

Antibiotic Coverage for Secondary Bacterial Pneumonia

• Initiate antibiotics if pneumonia is suspected, with first-line treatment being co-amoxiclav (amoxicillin-clavulanate) 625 mg three times daily orally. 1
• Alternative: doxycycline 200 mg initially, then 100 mg once daily for penicillin-allergic patients. 1, 2
• Common secondary bacterial pathogens include Streptococcus pneumoniae and Staphylococcus aureus. 3

Monitoring Requirements

• Monitor vital signs at least twice daily, including temperature, respiratory rate, pulse, blood pressure, and oxygen saturation. 1, 2
• Obtain chest x-ray during hospital assessment to evaluate for pneumonia. 3
• Check full blood count, urea, creatinine, electrolytes, and liver function tests in hospitalized patients. 3

Warning Signs Requiring Immediate Re-evaluation

• Shortness of breath at rest or with minimal activity 1
• Painful or difficult breathing 1
• Coughing up blood-stained sputum 3
• Worsening symptoms despite 48 hours of oseltamivir treatment 1
• Drowsiness or confusion 1

ICU/HDU Transfer Criteria

• Transfer to intensive care if: 3, 2
  • Persisting hypoxia with PaO2 <8 kPa despite maximal oxygen (SpO2 <92% despite FiO2 >60%)
  • Progressive hypercapnia (PaCO2 >6.5 kPa)
  • Severe acidosis (pH <7.26)
  • Septic shock or hemodynamic instability

Prophylaxis for Household Contacts

• Oseltamivir 75 mg once daily for 7-10 days can be used for household prophylaxis when administered within 48 hours of symptom onset in the infected person. 3, 6
• Prophylaxis is approximately 70-90% effective in preventing influenza illness. 3

Tolerability and Common Adverse Effects

• Oseltamivir is well tolerated in elderly patients, with nausea and vomiting being the most common adverse events (occurring in 1 in 7 patients). 6, 5
• Gastrointestinal effects are mild, transient, and less likely when oseltamivir is taken with food. 6
• These effects rarely result in treatment discontinuation. 8

Critical Pitfalls to Avoid

• Do not withhold oseltamivir if presentation is >48 hours from symptom onset—mortality benefit persists even with delayed initiation. 4
• Do not prescribe zanamivir (inhaled) for elderly patients with underlying respiratory disease due to risk of bronchospasm. 9
• Do not ignore worsening of pre-existing medical conditions—these patients require prompt reassessment. 1
• Do not rely on oseltamivir alone in nursing home outbreaks—consider prophylaxis for all residents to prevent spread. 5