The document discusses the clinical pharmacology of lower respiratory tract infections (LRTIs), emphasizing the significance of community-acquired pneumonia (CAP) as a leading cause of death due to infectious diseases and the high medical costs associated with it. It highlights challenges in managing CAP and exacerbations of chronic bronchitis, including diagnostic difficulties and rising antimicrobial resistance, while outlining recent advances in treatment guidelines suggesting combination therapies. The summary concludes that LRTIs are common in clinical practice, and effective management often relies on empirical antimicrobial therapy.

1. Clinical Pharmacology Of
Management Of Lower
Respiratory Tract Infections
(Including Recent
Advances)
Dr. Shakeeb
Dhorajiwala

2. Overview
Summary
Recent advances
Diseases & Management
Pneumonia & types Bronchitis: Acute & AEBE
Challenges
Symptomatologic distinctions
Introduction
Anatomical division Functional Distinctions
Problem statement
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3. Problem statements Why read about this topic?
1. CAP* leading cause of death due to
infectious diseases in developed
countries.[1]
2. Huge medical costs, those in the US
alone exceeding $ 10 billion per annum
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*Community Acquired pneumonia
1.Torres A, Peetermans WE, Viegi G, Blasi F. Risk factors for community-acquired pneumonia in adults in Europe: A literature review. Thorax 2013;68:1057-65 3

4. Introduction
GBD* 2015 study lower respiratory tract infections (LRTIs) fourth most
fatal after:
• IHD
• cerebro-VD [1]
LRTI- Acute illness (≤3-week) 1o symptom cough +≥1 other symptoms of
LRT viz expectoration, breathlessness, wheeze/ chest discomfort/pain
includes:
• a/c bronchitis
• pneumonia
• a/c exacerbation of chronic lung diseases such as COPD/bronchiectasis
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Global Burden of Disease
1. GBD 2015 Mortality and Causes of Death Collaborators. Global, regional, and national life expectancy, all-cause mortality, and cause-specific
mortality for 249 causes of death, 1980-2015: A systematic analysis for the global burden of disease study 2015. Lancet 2016;388:1459-544
4

5. Anatomical Division
Upper Airways Lower Airways
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6. Functional Distinctions
URTI
Conduction
Filtration
Humidification
Warming of inhaled air
LRTI
Conduction
Gas exchange
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7. Comparison of Symptomatology
URTI LRTI
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8. Challenges
Management of CAP*
and AECB*
challenging because
of:
• diagnostic difficulty in
differentiating infections
caused by typical &
atypical microorganisms
• rising rates of
antimicrobial resistance
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*COMMUNITY-ACQUIRED PNEUMONIA
*A/C EXACERBATION OF CHRONIC BRONCHITIS
8

9. Pneumonia
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10. Pneumonia classification:
CAP HAP VAP HCAP
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Community
acquired
hospital-
acquired
pneumonia
Ventilator-
associated
health care–
associated
pneumonia
10

11. Stages of Pneumonia
Stage Time Macroscopy Microscopy
1. Congestion <24 hrs Red, heavy,
boggy
Vessels dilated,
alveolar exudate
with bacteria
2. Red
hepatization
2-3 days Red, airless Alveolar exudate
+ neutrophils,
RBCs, fibrin
3. Gray
hepatization
4-6 days Grey Fragmented
RBCs+pic as
stage 2.
4. Resolution > 6 days Normal Enzymatic
digestion of
exudates
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12. 12/21/2022 12
X-ray Distinctions
Perihilar Patchy infiltrations
Lung consolidation

13. 12/21/2022
HTTPS://WWW.KEVINMD.COM/2018/03/LEARN-TYPICAL-COMMUNITY-ACQUIRED-PNEUMONIA-MEDCOMIC.HTML
13

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Microbial Causes of Community-Acquired Pneumonia

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HTTPS://WWW.NEWS-MEDICAL.NET/NEWS/20201218/TRANSFER-LEARNING-EXPLOITS-CHEST-XRAY-TO-DIAGNOSE-COVID-19-PNEUMONIA.ASPX
15

16. 12/21/2022 16
Rx of CAP

17. Treatment
regimen in
India
1. Beta-
Lactam
2. Macrolides
3. FQs
17 12/21/2022
REF- MAHASHUR A. MANAGEMENT OF LOWER RESPIRATORY TRACT INFECTION IN
OUTPATIENT SETTINGS: FOCUS ON CLARITHROMYCIN. LUNG INDIA 2018;35:143-9.

18. 12/21/2022 18
Rx of
HAP
&
VAP

19. Differentiating Features Atypical Pneumonia
L. pneumophilia m/c
cause
• ICS patients, smokers
& elderly more
susceptible
• 1o symptoms:
• GI symptoms,
headache, confusion,
haemoptysis,
dyspnoea & MSK
(myalgia, arthralgia)
M. pneumoniae
• 1o symptoms:
• fever, cough, sore
throat, coryza,
bullous myringitis,
pharyngitis &
crepitations
C. pneumoniae
• 1o symptoms:
• sore throat,
nonproductive cough,
hoarseness of voice,
headache,
pharyngitis, and
wheezing
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20. Bronchitis:
Acute & AEBE
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23. Rx of AECB
Clarithromycin 500
mg BD x 7 days-
• Amoxycillin 500 mg TID x
7 days
• Cefuroxime axetil 250
mg BD x 7 days
Alternatives:
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24. Recent Advances:
Changes in
ATS-IDSA
Guidelines
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25. 12/21/2022
Metlay JP. Et al Diagnosis and Treatment of Adults with Community-acquired Pneumonia An Official Clinical Practice Guideline of the American Thoracic Society
and Infectious Diseases Society of AmericaAmerican Journal of Respiratory and Critical Care Medicine Volume 200 Number 7 | October 1 2019 25

26. Summary
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LRTIs are common problems in
day-to-day clinical practice
Antimicrobial therapy is a principal
management
Due to infrastructural limitations
physician resorts to empirical
therapy  antimicrobial resistance
Recent changes in guidelines
suggests combination therapy using
macrolide and beta-lactam antibiotic

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