Outpatient OPD Pneumonia: Amoxicillin & Cefdinir Regimens Explained

✅ 1. Amoxicillin Regimen (Ready to Use)

Amoxicillin (500 mg) 2×3 po pc for 7 days

✔ Meaning: 500 mg tablets, take 2 tablets (1 g) three times a day, after meals, for 7 days.

Final Prescription Line:

Amoxicillin (500 mg) 2×3 po pc × 7 days

✅ 2. Cefdinir Regimen (Ready to Use)

Two common OPD pneumonia dosing patterns exist. Use whichever your professor prefers.

Option A: Standard Adult CAP Regimen

Cefdinir (300 mg) 1×2 po bid × 7 days

✔ Meaning: 300 mg one capsule, twice a day, for 7 days.

Option B: High-Dose OPD Regimen (for older adults or comorbidities)

Cefdinir (300 mg) 2×1 po qd × 7 days

✔ Meaning: 300 mg two capsules once daily (total 600 mg/day).

📌 Summary Table

Drug	Regimen	Duration
Amoxicillin	Amoxicillin (500 mg) 2×3 po pc	7 days
Cefdinir – BID regimen (preferred)	Cefdinir (300 mg) 1×2 po bid	7 days
Cefdinir – once daily regimen	Cefdinir (300 mg) 2×1 po qd	7 days

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Introduction

Community-acquired pneumonia (CAP) is one of the most common respiratory infections encountered in outpatient (OPD) settings. While severe cases require hospitalization, most mild CAP cases can be safely managed in the outpatient department when clear criteria are met. Choosing proper evaluation, antibiotic therapy, supportive management, and follow-up is crucial for safe patient care.

This article reviews diagnosis, severity assessment, criteria for OPD management, antibiotic selection, and follow-up strategy for CAP.

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🩺 1. Diagnosis of CAP in OPD

Typical symptoms

• Fever

• Cough (productive or dry)

• Dyspnea

• Pleuritic chest pain

• Fatigue, malaise
  

Physical examination findings

• Fever, tachypnea

• Localized crackles or crepitation

• Decreased breath sounds

• Bronchial breath sounds

• Dullness to percussion (if consolidation present)
  

Common OPD investigations

• Chest X-ray (if accessible): consolidation, infiltrates

• Pulse oximetry

• CBC if available

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🧮 2. Assessing Severity: Who Can Be Treated as OPD?

The most widely used tools:

CURB-65 Score

Parameter	Point
Confusion	1
Urea > 20 mg/dL	1
RR ≥ 30/min	1
BP < 90 systolic or ≤ 60 diastolic	1
Age ≥ 65	1

Interpretation

• 0–1: Treat as OPD

• 2: Consider admission

• ≥3: Require admission/IPD
  

Additional OPD criteria

• SpO₂ ≥ 92–94% on room air

• Hemodynamically stable

• No mental status changes

• Able to take oral medication

• No severe comorbidities (HF exacerbation, severe COPD, CKD, immunosuppression)

• Adequate social support (can return for follow-up)

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🏥 3. When NOT to Treat in OPD (Must Admit)

• SpO₂ < 92%

• Respiratory rate ≥ 30/min

• SBP < 90 mmHg

• Confusion

• Multilobar infiltrates on CXR

• High fever with sepsis

• Unable to maintain hydration

• Severe vomiting

• Immunocompromised

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💊 4. OPD Antibiotic Management

Guidelines referenced: IDSA/ATS 2019, Thai CPG CAP 2021

For healthy young adults (no comorbidities)

First-line:

• Amoxicillin 1 g po tid for 5–7 days

• Doxycycline 100 mg po bid for 5–7 days

Alternative:

• Azithromycin (500 mg day 1, then 250 mg daily x 4 days)(only in areas with low macrolide resistance)
  

For patients with comorbidities

(e.g., diabetes, chronic lung disease, heart disease)

Combination therapy:

• Amoxicillin/clavulanate 875/125 mg po bid for 7 daysPLUS

• Azithromycin 500 mg day 1 → 250 mg x 4 daysOR

• Doxycycline 100 mg po bid
  

Why do some clinicians choose cefdinir?

(Not first-line in guidelines, but used clinically)

• Tolerated well

• Good for typical bacterial CAP

• Easy OPD regimen (300 mg BID x 7 days)

• Often used in pediatric pneumonia

• Useful when patient cannot take macrolides/doxycycline

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🌿 5. Supportive Management in OPD

• Paracetamol 500–1000 mg q6h PRN (fever/pain)

• Adequate oral hydration

• Rest for 48–72 hours

• Saline nebulizer or mucolytics if productive cough

• Avoid smoking

• Salbutamol inhaler PRN if bronchospasm

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📅 6. Follow-Up & Monitoring

Follow-up OPD visit:

• 48–72 hours after starting antibiotics

Expected improvement:

• Fever improves in 2–3 days

• Cough improves in 7–10 days

• Chest pain improves in 3–5 days

Return immediately if:

• Worsening dyspnea

• SpO₂ < 92%

• New confusion

• Persistent high fever > 3 days

• Cannot tolerate oral intake

Repeat chest X-ray

• Optional unless:

  • 50 years old

  • Smoker

  • Symptoms persist beyond 6–8 weeks

  • Suspicion of malignancy or TB

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⚠️ 7. Complications to Watch for

• Parapneumonic effusion

• Empyema

• Sepsis

• Respiratory failure

• Lung abscess

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📘 Case Example (Short Form for Exams)

33-year-old male with fever, productive cough, and chest discomfort for 3 days.Vitals stable, SpO₂ 96% RA, RR 20/min. CXR shows RLL consolidation. CURB-65 = 0 → OPD treatment appropriate.

Treatment:

• Amoxicillin 1 g tid x 7 days

• Paracetamol PRN

• Follow-up in 48 hours

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🎓 Conclusion

Most mild community-acquired pneumonia cases can be managed safely as OPD when the patient is hemodynamically stable, able to take oral medication, and meets severity criteria. Antibiotic regimens must follow evidence-based guidelines, with amoxicillin, doxycycline, and macrolides as first-line agents. Supportive care and timely follow-up ensure safe recovery and prevention of complications.