This document discusses the treatment of acute respiratory infections (pneumonias). Pneumonia is an infection of the lung parenchyma that is usually caused by bacteria like Streptococcus pneumoniae. It is characterized by cough, purulent sputum, and fever, along with physical signs or radiological changes. Management involves administering antibiotics empirically based on severity, later narrowing the choice based on culture results. For mild cases, oral amoxicillin is recommended, while more severe cases in the hospital receive amoxicillin plus a macrolide. Complications can include lung abscesses or empyemas.

1. TREATMENT OF ACUTE
RESPIRATORY INFECTIONS
(PNEUMONIAS)
By
Dr. Mohamed Farouk Ahmed, PhD
Assistant Professor of Clinical Pharmacology - Faculty of Medicine - University of Jeddah
RESPIRATORY SYSTEM
MODULE

2. Learning objectives
 What is Pneumonia?
 List the precipitating factors of pneumonia.
 Demonstrate the clinical features & investigations of pneumonia.
 List the complications of pneumonia.
 Explain the management of pneumonia.

3. What is Pneumonia?
• Infection of the lung parenchyma.
• Causative agents include:
I. Bacteria.
II. Viruses.
III. Fungi.
www.netmedicine.com/xray/xr.htm

4. Definition
• Pneumonia is an infection of the pulmonary parenchyma, pneumonia is
often misdiagnosed, mistreated, and underestimated.
• It is usually caused by bacteria (Strep. pneumoniae).
• Clinically it is characterized by the presence of
1- Cough, purulent sputum and fever.
2- Physical signs or radiological changes.

5. Precipitating factors
I. Strep. pneumoniae - often follows viral infection.
II. Hospitalized 'ill' patients - often infected with gram-negative organisms.
III. Cigarette smoking and alcohol.
IV. Bronchiectasis (e.g. in cystic fibrosis).
V. Immunosuppression (e.g. AIDS).
VI. Intravenous drug abuse.

6. Clinical features
 The clinical presentation varies according to the immune state of the
patient and the infecting agent.
A) Symptoms
 The patient rapidly becomes ill with a high fever.
 Pleuritic pain.
 Dry cough , rusty-coloured mucus.

7. B) Signs
• High temperature (up to 39.5°C).
• Rapid and shallow breathing.
• The affected side of the chest moves less, and signs of consolidation may
be present with a pleural rub.
Investigations
1- Plain X-ray
- Confirms the area of consolidation.
2- CT chest may be needed.

8. A chest X-ray showing a very prominent wedge-shaped
bacterial pneumonia in the right lung

9. Complications
1- Lung abscess
• Abscesses may develop during the course of specific pneumonias,
particularly when the infecting agent is Staph. aureus or Klebsiella
pneumoniae.
• Amoebic abscesses may develop in the right lower lobe following spread
from an amoebic liver abscess.
• The patient is often anaemic with a high ESR.

10. 2- Empyema:
• Empyema means the presence of pus within the pleural cavity.
• This usually arises from bacterial spread from a severe pneumonia or after
the rupture of a lung abscess into the pleural space.
• Empyemas should be treated by prompt tube drainage or by rib resection
and drainage of the empyema cavity under ultrasound control.

11. Management
• Sputum and blood should always be sent for culture but antibiotic
treatment should not be delayed.
• Severe cases need to be admitted to hospital and a chest X-ray is
performed.
• Other investigations, e.g. blood gases, are useful to detect respiratory
failure and provide a baseline for comparison if the patient deteriorates.

12. • The choice of antibiotics is inevitably empirical, and is largely directed at
Streptcoccal pneumoniae infections.
1- For treatment of mild community-acquired pneumonia:
1- oral amoxicillin at a dose of at least 500 mg/8h.
2- oral erythromycin (or clarithromycin) is an alternative choice for those
sensitive to penicillin.

13. 2- For more severe cases treated in hospital:
1- combined therapy with amoxicillin and a macrolide (erythromycin or
clarithromycin) is recommended.
2- when oral therapy is contraindicated, parenteral ampicillin should be
combined with clarithromycin.
3- For staph. aureus infection:
1- intravenous flucloxacillin ± sodium fusidate.
2- Fluoroquinolones are recommended for those intolerant of penicillins or
macrolides.

14. 4- For resistant cases:
1- parenteral antibiotics should be given with the combination of a broad-
spectrum beta-lactam antibiotic (cefuroxime) and clarithromycin.
5- Parenteral antibiotics:
1- should be switched to oral once the temperature has settled for a period
of 24 hours and provided there is no contraindication to oral therapy.
6- Finally, the choice of antibiotics may be narrowed once microbiological
results are available.

15. • Lippincott illustrated reviews pharmacology 5th Edition.
• Rang & Dale's Pharmacology. 9th Edition.
• Goodman and Gilman's the pharmacological basis of therapeutics 13th edition.
• Katzung basic and clinical pharmacology 12th edition.
References