PHARMACOTHERAPY III PHCY 510 University of Nizwa College of Pharmacy and Nursing School of Pharmacy PHARMACOTHERAPY III PHCY 510 Lecture 5 Infectious Diseases “Lower Respiratory Tract Infections” Dr. Sabin Thomas, M. Pharm. Ph. D. Assistant Professor in Pharmacy Practice School of Pharmacy, CPN University of Nizwa

Course Outcome Upon completion of this lecture the students will be able to Describe pathophysiology, clinical presentation (signs and symptoms) diagnosis, investigations, treatment strategies, and follow up of bronchitis and pneumonia. Individualize the antimicrobial treatments among bronchitis and pneumonia patients.

Lower respiratory tract infections include infectious processes of the lungs and bronchi, pneumonia, bronchitis, bronchiolitis, and lung abscess. Bronchitis refers to an inflammatory condition of the tracheobronchial tree with a generalized respiratory infection. Classified as either acute or chronic

Acute bronchitis occurs during winter months and begins as an upper respiratory infection. Respiratory viruses are by far the most common infectious agents associated with acute bronchitis. The common cold viruses, rhinovirus and coronavirus, and lower respiratory tract pathogens, including influenza virus, adenovirus, and respiratory syncytial virus. Mycoplasma pneumoniae also appears to be a frequent cause of acute bronchitis. Other bacterial causes include Chlamydia pneumoniae and Bordetella pertussis.

Clinical Presentation Nonspecific complaints such as malaise and headache, coryza (inflammation of mucous membrane in the nose), and sore throat. Cough is the hallmark of acute bronchitis initially nonproductive but progresses, yielding mucopurulent sputum. Chest examination may reveal rhonchi and coarse, moist rales bilaterally.

Treatment M. pneumoniae treated with azithromycin or levofloxacin. Mild analgesic-antipyretic therapy are often helpful in relieving the associated lethargy, malaise, and fever. Acetaminophen (650 mg in adults or 10 to 15 mg/kg per dose in children). Ibuprofen (200 to 800 mg in adults or 10 mg/kg per dose in children. M. pneumoniae treated with azithromycin or levofloxacin.

Pneumonia Infection or inflammation of the lung parenchyma. Of infective origin and characterized by consolidation (pus, bacteria, WBC and exudates filling alveoli and appear on chest x‐ray as opaque shadow). Classified according to the nature of its acquisition as community acquired (CAP) or hospital acquired pneumonia (HAP) Causative Organisms: Typical: Streptococcus pneumonia and Haemophilus influenzae Atypical: Ligionella pneumophila, Mycoplasma pneumonia, Chlamidophila pneumonia

Chest x‐ray showing severe, bilateral pneumonia

Community Acquired Pneumonia (CAP) Diagnosis: sputum culture, bronchoscope lavage fluid for microscopy and culture. Atypical pneumonia is determined by serology Targeted Treatment: Pneumococcus pneumonia benzylpenicillin, amoxicillin, erythromycin. Combination of a beta‐lactam and a macrolides may reduce mortality Chlamedophila pneumonia: doxycycline and quinolones Staphylococcus spp.: flucloxacillin, vancomycin Legionella (legionnaire’s disease): rifampicin, quinolones, azithromycin Moderate to severe disease: hospital admission, combination of a beta‐lactam and a macrolide/doxycycline, moxifloxacin

Hospital Acquired Pneumonia (HAP) (Nosocomial Pneumonia) Causative organisms: gram –ve bacilli (Enterobacter, Pseudomonas spp. And Acinetobacter spp.) and.. gram +ve cocci (S. aureus including MRSA) Usually acquired in intensive care units (ICU) (50%) where broad spectrum antibiotics are used. Clinical Features: nosocomial pneumonia accounts for 10‐15% of acquired infections- sepsis, respiratory failure.

Diagnosis: sputum, bronchoalveolar lavage and blood culture. Predisposing factors include: stroke, mechanical ventilation, COPD, surgery, immunosupression and previous antibiotic use. Diagnosis: sputum, bronchoalveolar lavage and blood culture. Treatment: broad spectrum empiric therapy is indicated. Influenced by previous antibiotics, surgery and duration of admission Combination therapy include: Aminoglycoside + penicillin / cephalosporin Aminoglycoside + clindamycin Vancomycin / linezolid + ciprofloxacin

Prevention: Postoperative mobilization, physiotherapy, and rational antibiotic use. Administration of aerosolized antibiotics for prevention of ventilator‐associated pneumonia.