What are the guidelines for the appropriate use of antibiotics in patients with respiratory tract infections?

The appropriate use of antibiotics in patients with respiratory tract infections (RTIs) is guided by several factors, including the specific type of infection, patient risk factors, and diagnostic indicators.

• General Principles for Antibiotic Prescribing:
  • An immediate antibiotic prescription should be offered if the person is systemically very unwell on face-to-face examination ¹.
  • An immediate or back-up antibiotic prescription can be considered for individuals at higher risk of complications, such as those with pre-existing comorbidities or older age ¹.
  • For non-severe infections, consider taking microbiological samples before deciding on an antimicrobial, provided it is safe to withhold treatment until results are available ⁴.
  • Do not routinely offer antibiotics for acute cough associated with acute bronchitis unless the person is systemically very unwell or at higher risk of complications ¹.
  • Do not issue an immediate prescription for an antimicrobial to a patient likely to have a self-limiting condition ⁴. Instead, discuss self-care with over-the-counter preparations or back-up (delayed) prescribing ⁴.
  • Prescribers should discuss the likely nature of the condition, why an antimicrobial may not be the best option, alternative options, and safety-netting advice with the patient ⁴.
  • Document the reason for prescribing or not prescribing an antimicrobial, and the plan of care, including planned duration ⁴.
  • Do not issue repeat prescriptions for antimicrobials unless needed for a specific clinical condition or indication ⁴.
• Diagnostic Guidance:
  • For lower respiratory tract infections (LRTIs), a point-of-care C-reactive protein (CRP) test can support clinical decision-making ².
  • Offer immediate antibiotics if the CRP level is greater than 100 mg/L ¹,².
  • Consider a delayed or back-up antibiotic prescription if the CRP level is between 20 mg/L and 100 mg/L ¹,².
  • Do not routinely offer antibiotics if the CRP level is less than 20 mg/L ¹,².
  • Do not offer rapid point-of-care microbiological tests or influenza tests to determine whether to prescribe antimicrobials for suspected acute respiratory infection ².
• Antibiotic Choice and Duration for Specific RTIs:
  • Acute Cough and Bronchitis:
    • If antibiotic treatment is appropriate, oral doxycycline (200 mg on day 1, then 100 mg once daily for 4 days, total 5-day course) is the first choice for adults (excluding pregnant women) ¹.
    • Amoxicillin should be reserved for more serious infections with a higher likelihood of bacterial infection, such as pneumonia, to avoid driving resistance ¹.
    • Alternative first choices for adults include oral amoxicillin (preferred in pregnant women), clarithromycin, or erythromycin ¹.
    • For young people aged 12–17 years, oral amoxicillin (500 mg three times a day for 5 days) is the first-line choice (preferred in pregnant young women) ¹.
    • Alternative first choices for young people aged 12–17 years include oral clarithromycin, erythromycin (preferred in pregnant young women), or doxycycline (not for pregnant young women) ¹.
    • If antibiotic treatment is appropriate, a 5-day course is considered adequate to treat acute cough, while minimising the risk of resistance ¹. The shortest effective course should be used ¹.
    • Do not offer oral or inhaled bronchodilators, oral or inhaled corticosteroids, or mucolytics for acute cough associated with acute bronchitis unless there is underlying airway disease such as asthma ¹.
  • Community-Acquired Pneumonia (CAP):
    • Start antibiotic treatment as soon as possible after establishing a diagnosis (within 4 hours, or within 1 hour if the person has high-risk criteria for sepsis) ¹.
    • In the low-severity adult group, amoxicillin is considered the first choice due to its good activity against Streptococcus pneumoniae, low adverse effects, and resistance rates ¹.
    • Doxycycline, clarithromycin, and erythromycin are alternative choices ¹.
  • Acute Exacerbations of Chronic Obstructive Pulmonary Disease (AECOPD):
    • Antibiotic therapy should be considered where an infective exacerbation is suspected, based on changes in clinical features such as increased volume and change in colour and consistency of sputum ³.
    • The decision to prescribe antibiotics should be made on an individual patient basis, balancing the uncertain benefit against symptom severity, need for hospital treatment, exacerbation history, risk of complications, and previous sputum culture results ³.
    • If a person is receiving prophylactic antibiotics, treatment for an acute exacerbation should be with an antibiotic from a different class ³.
    • Broader-spectrum antibiotics should be reserved for those at higher risk of treatment failure ³.
    • Reassess people with an acute exacerbation of COPD if their symptoms worsen rapidly or significantly, considering other diagnoses like pneumonia or signs of more serious illness ³.
    • Send a sputum sample for culture and sensitivity testing if symptoms have not improved following antibiotic treatment and this has not already been done ³.