Community- acquired Pneumonia Author Dr. Shek Kam Chuen Oct 2013 HKCEM College Tutorial

History ▪ M/39 ▪ Good past health ▪ Fever one day, 38.8 o C ▪ Cough with yellowish sputum ▪ Right pleuritic chest pain

Any other important history? ▪ FTOCC ▪ Travel: Middle East, Avian flu ▪ Occupation: virus laboratory worker, poultry worker, work in wet market ▪ Contact: Poultry contact or index case ▪ Cluster: any, ?Amoy Garden in 2003 March

Case one: CAP Out-patient Tx ▪ FTOCC –ve ▪ What is clinical diagnosis? ▪ CAP, clinically stable ▪ What antibiotics shall we give? ▪ What are the common pathogens in HK?

What are possible pathogens? ▪ Bacterial ▪ Atypical ▪ Viral

Community Acquired Pneumonia ▪ Local pathogens in order of commonest : ▪ Haemophilus influenzae (13.7%-60%) ▪ Streptococcus pneumoniae ▪ Moraxella catarrhalis ▪ Chlamydia pneumoniae ▪ Legionella ▪ Mycoplasma ▪ Not to forget TB (esp elderly) or viral agents ▪ Local A&E sputum culture (QEH & PMH) data suggests H. influenzae is much more common than S. pneumoniae. Big 3 Atypical

Subsequent treatment Augmentin 1g BD 1/52 +Azithromycin 500mg daily for 3/7 Sputum CST + AFB CST saved Follow up in 5/7

What are components of Augmentin? ▪ β-lactam/β-lactamase inhibitors combinations ▪ Amoxicillin-clavulanate (Augmentin) ▪ MSSA, ▪ S. pneumoniae, ▪ H. influenzae, ▪ M. catarrhalis, ▪ some E-coli, anaerobes ▪ 1. Augmentin 375mg tds =(amoxil250 + clavulanate125)x3 =amoxil750 + clavunanate375/D ▪ 2. Augmentin 375+ amoxil250 tid =amoxil1500 +clavunanate 375 /D ▪ 3. Augmentin 1 gm bd =(amoxil 875+caluvulanate 125)x2 =amoxil1750+calvunanate250/D

Why Azithromycin added? ▪ Macrolides are good at CAP atypical agents and campylobacter(GE). ▪ Newer macrolides (clarithromycin, azithromycin) have a better coverage of H. influenzae. But there are wide spread resistance among the common Gram-positive bacteria including MSSA, Pneumococcus, Group A Streptococcus. ▪ not be used as single empirical treatment of CAP and soft tissue infections to substitute penicillin in penicillin-allergy patients

At Follow-Up, Afebrile for 3 days, Feel better but still cough, CXR: more or less the same Sputum grew:  Streptococcus Pneumoniae ▪ Levofloxacin: S ▪ Penicillin (CNS): R ▪ Penicillin (non CNS): S ▪ Vancomycin : S

What is subsequent MX? A. levofloxacin 500mg daily x 7 days B. iv vancomycin C. Change Klacid 500mg BD 1/52 D. Continue high dose Augmentin E. Consult microbiologist whether the S. Pneumoniae is S to Augmentin Ans D

First line Antibiotics for CAP ▪ Higher dose Augmentin or Unasyn in view of drug resistant S. Pneumoniae DRSP infection Augmentin 1gm BD or (Augmentin 375mg tds + amoxycillin 250mg tds) + Azithromycin(Zithromax) is preferred in view of no major drug interaction 9 9 Clarithromycin (Klacid) is P-450 cytochrome inhibitor with multiple drug interactions

What is the role Fluoroquinolones? ▪ Fluoroquinolone inhibit DNA gyrase and useful in G+ve and G-ve bacteria. But the resistance is increasing. ▪ Not for 1 st line for CAP in HK ▪ Which quinolones? ▪ Levofloxacin is more potent than ciproxin against S. Pneumoniae

Fluoroquinolones are used as second line for CAP ▪ for adults when the first line regime is failed ▪ Allergic to alternative agents ▪ Documented infection due to pneumococci with high level penicillin resistance (Penicillin MIC >=4UG /mL.) ▪ (it is not used as first line since it may mask TB and may cause drug resistance in future.) ▪ levofloxacin 750mg QD for 5/7 because it is concentration dependent. CID 2007;44 (Suppl 2) S27-S72 Impact

Thank You