What is the first-line antibiotic for an adult patient with an upper respiratory tract infection (URTI) and no underlying conditions, such as immunocompromised status?

First-Line Antibiotic for Upper Respiratory Tract Infection

Antibiotics should NOT be prescribed for uncomplicated upper respiratory tract infections (URTIs) in adults, as these infections are predominantly viral and antibiotic treatment does not enhance illness resolution, prevent complications, or reduce symptom duration. 1

When Antibiotics Are NOT Indicated

The vast majority of nonspecific URTIs are viral in origin and resolve spontaneously within 1-2 weeks, with most patients feeling better within the first week. 1

Key points against antibiotic use:

• Antibiotic treatment does not decrease symptom duration or lost work time in uncomplicated URTIs 1
• Purulent nasal discharge and sputum do NOT predict bacterial infection and do not benefit from antibiotic treatment 1, 2
• Complications such as bacterial rhinosinusitis or bacterial pneumonia are rare 1
• Life-threatening complications of URTI are exceedingly rare 2

Common Pitfall to Avoid

The presence of purulent secretions (green or yellow nasal discharge or sputum) is NOT an indication for antibiotics. This is commonly observed in viral URTIs and does not predict bacterial superinfection. 1, 2

When to Consider Antibiotics (Specific Bacterial Complications)

Antibiotics are only appropriate when a URTI progresses to a specific bacterial complication:

Acute Bacterial Rhinosinusitis (ABRS)

• First-line: Amoxicillin is the recommended first-line agent 1
• Only treat when symptoms persist >10 days without improvement, or when symptoms worsen after initial improvement (double-worsening) 1
• Observation without antibiotics is an option for mild illness (mild pain, temperature <38.3°C) with assured follow-up 1

Group A Streptococcal Pharyngitis

• First-line: Penicillin V for 10-14 days 3, 4
• Only treat when clinical criteria or rapid antigen testing confirms streptococcal infection 4
• Antibiotics are NOT indicated for viral pharyngitis 3

Acute Otitis Media

• First-line: Amoxicillin 4
• This is primarily a pediatric condition 4

Harm of Inappropriate Antibiotic Use

Prescribing antibiotics for viral URTIs causes:

• Adverse drug events (diarrhea, rash, Stevens-Johnson syndrome, anaphylaxis) with number needed to harm of 9 1
• Increased antibiotic resistance in the community, particularly for Streptococcus pneumoniae 1
• Previous antibiotic use is the most important risk factor for carrying antibiotic-resistant pathogens 1
• Unnecessary costs to patients and healthcare systems 1
• Potential long-term effects including disruption of intestinal microbiota 1

Appropriate Management of Uncomplicated URTI

Symptomatic relief is the cornerstone of management:

• Analgesics for pain relief 1
• Reassurance that symptoms typically resolve within 1-2 weeks 1
• Patient education about the viral nature of the illness 1

When to Reassess

Patients should return if:

• Symptoms worsen or fail to improve after 7 days 1
• Fever persists beyond 7 days (may indicate bacterial superinfection) 1
• New symptoms develop suggesting complications 1