In an adult smoker with a two‑week history of fever (101.2 °F) and productive cough, what antibiotic regimen should be prescribed?

Amoxicillin is the first-line antibiotic for this patient with suspected community-acquired pneumonia

For an adult smoker with two weeks of fever (101.2°F) and productive cough, you should prescribe amoxicillin as first-line therapy, assuming this is outpatient community-acquired pneumonia (CAP). If the patient has used antibiotics in the past 3 months or has comorbidities, escalate to a respiratory fluoroquinolone (levofloxacin or moxifloxacin) or combine amoxicillin with a macrolide 1, 2.

Clinical Context and Diagnosis

This presentation—fever, productive cough for two weeks in a smoker—strongly suggests CAP rather than acute bronchitis. Key distinguishing features include:

• Duration: Two weeks of symptoms with persistent fever points toward pneumonia rather than self-limited bronchitis (which typically resolves in 2-3 weeks) 3, 4
• Smoking history: Pack-a-day smokers have increased risk for bacterial pneumonia, particularly from Streptococcus pneumoniae and Haemophilus influenzae 5
• Fever of 101.2°F: Sustained fever is more consistent with pneumonia than bronchitis 6

Critical step: Obtain a chest X-ray if available to confirm pneumonia, especially given abnormal vital signs (fever) 6. If imaging is unavailable, empiric antibiotic treatment is appropriate given the high clinical suspicion 6.

Antibiotic Selection Algorithm

First-Line (No Recent Antibiotics, No Comorbidities):

• Amoxicillin is the preferred agent 7
• Alternative: Doxycycline 1, 2
• Alternative: Azithromycin (macrolide) 2

Second-Line (Recent Antibiotic Use Within 3 Months OR Comorbidities):

• Respiratory fluoroquinolone (levofloxacin, moxifloxacin) 1, 2
• OR amoxicillin PLUS azithromycin 2

Penicillin Allergy:

• Respiratory fluoroquinolone 1
• OR doxycycline 1

Why NOT the Other Options from Your List?

• Penicillin: Less effective oral bioavailability compared to amoxicillin for outpatient pneumonia; not recommended in modern guidelines 1
• Ciprofloxacin: Not a respiratory fluoroquinolone; inadequate pneumococcal coverage; reserved for Pseudomonas risk (not present here) 1
• Tetracycline: Doxycycline (a tetracycline) is acceptable as an alternative, but amoxicillin remains first-line 1, 2

Common Pitfalls to Avoid

1. Don't confuse this with acute bronchitis: The two-week duration with persistent fever makes pneumonia more likely. Acute bronchitis doesn't warrant antibiotics 8, 3, 4, but pneumonia does 1, 6

2. Don't use ciprofloxacin for routine CAP: It lacks adequate coverage for S. pneumoniae, the most common pathogen. Reserve it for Pseudomonas risk factors (bronchiectasis, recent hospitalization, recent broad-spectrum antibiotics) 1

3. Smoking status matters: This patient's smoking history increases risk for H. influenzae and S. pneumoniae, reinforcing the need for appropriate coverage 5

4. Consider macrolide resistance: In regions with high macrolide-resistant pneumococcus (>25%), avoid azithromycin monotherapy 1. Amoxicillin or fluoroquinolones remain effective.

Duration and Follow-Up

• Treat for 5-7 days for uncomplicated CAP
• Re-evaluate in 2-3 days if symptoms worsen or fail to improve 7
• Chest X-ray in 6-8 weeks for smokers aged 50+ to rule out underlying malignancy 7