What is the treatment for pneumonia in a 19-year-old?

Treatment of Pneumonia in a 19-Year-Old

For a 19-year-old with community-acquired pneumonia appropriate for outpatient management, treat with oral amoxicillin 1000 mg three times daily (or high-dose amoxicillin 90 mg/kg/day) for 7-10 days; if hospitalization is required due to severity markers (oxygen saturation <92%, respiratory distress, inability to tolerate oral intake), initiate intravenous beta-lactam/macrolide combination therapy such as ceftriaxone 1-2g daily plus azithromycin 500mg daily for a minimum of 3 days. 1

Initial Assessment and Severity Stratification

Determine if outpatient or inpatient management is appropriate:

• Admit to hospital if any of the following are present: oxygen saturation <92%, respiratory rate >50 breaths/min (though this threshold is pediatric-focused, tachypnea >30 in adults warrants concern), difficulty breathing or grunting, signs of dehydration, vomiting preventing oral intake, or suspected bacteremia 2, 1
• Outpatient management is appropriate for patients without these severity markers who can reliably take oral medications and have adequate social support 1
• Test for COVID-19 and influenza when these viruses are circulating in the community, as positive results will alter treatment with antiviral therapy 1

Outpatient Antibiotic Management

For mild community-acquired pneumonia treated as outpatient:

• First-line therapy: Oral amoxicillin at high doses (approximately 1000 mg three times daily for adults, or 90 mg/kg/day in divided doses) for 7-10 days 2, 1
• Alternative regimens: Azithromycin or fluoroquinolones can be considered, though azithromycin should be reserved for cases where atypical organisms (Mycoplasma pneumoniae, Chlamydia pneumoniae) are suspected 3, 4
• Duration: 7-10 days is standard, with clinical improvement expected within 48-72 hours 2

Inpatient Antibiotic Management

For hospitalized patients without risk factors for resistant bacteria:

• Recommended regimen: Beta-lactam/macrolide combination therapy such as ceftriaxone (1-2g IV daily) combined with azithromycin (500mg IV daily) for a minimum of 3 days 1
• Alternative beta-lactams: Ampicillin-sulbactam, cefuroxime, or cefotaxime can be used 5, 2
• Transition to oral therapy when the patient is afebrile, tolerating oral intake, and shows clinical improvement (typically after 3 days of IV therapy), then complete 7-10 days total antibiotic duration 5, 1

Respiratory Support and Monitoring

Oxygen therapy and supportive care:

• Maintain oxygen saturation >92% at all times using nasal cannula, face mask, or high-flow nasal oxygen as needed 3, 2
• Monitor for deterioration: increased work of breathing, altered mental status, persistent fever, or worsening hypoxemia 5
• Avoid chest physiotherapy as it provides no benefit 5, 4

Additional Supportive Measures

Symptomatic and preventive care:

• Fever management: Use ibuprofen 200mg orally every 4-6 hours (maximum 4 times in 24 hours) when temperature exceeds 38.5°C; maintain temperature around 38°C as very low temperatures may impair antiviral immune responses 3
• Hydration: Ensure adequate fluid intake; for hospitalized patients, administer IV fluids at 80% maintenance to prevent SIADH, with daily electrolyte monitoring 5
• Nutrition: Protein-rich diet with ideal energy intake of 25-30 kcal/kg/day and protein 1.5 g/kg/day 3
• VTE prophylaxis: Evaluate venous thromboembolism risk and use low-molecular-weight heparin in high-risk hospitalized patients without contraindications 3

Important Caveats and Pitfalls

Antibiotic selection considerations:

• Avoid azithromycin monotherapy for typical bacterial pneumonia in this age group, as it may have inadequate coverage for Streptococcus pneumoniae and Haemophilus influenzae 4
• Be aware of QT prolongation risk with azithromycin, particularly if the patient has underlying cardiac conditions, electrolyte abnormalities, or is taking other QT-prolonging medications 6
• Azithromycin adverse effects include potential for hepatotoxicity, Clostridium difficile-associated diarrhea, and allergic reactions ranging from rash to anaphylaxis 6
• Avoid broad-spectrum antibiotics unless there are specific risk factors for resistant organisms or healthcare-associated pneumonia 3

Follow-up and Re-evaluation

Monitoring response to therapy:

• Outpatients should be re-evaluated within 48-72 hours if not improving or if symptoms worsen 4, 2
• Hospitalized patients can be discharged when afebrile for ≥24 hours, oxygen saturation >92% on room air, normalized respiratory rate, and tolerating adequate oral intake 5
• Chest radiograph follow-up may be considered 4-6 weeks after treatment in patients with persistent symptoms or risk factors for underlying lung pathology 7