This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pneumonia, Subject name: Medicine
All are recommended for treatment of Primary lung abscess except: 
Select and explain. 
A. Moxifloxacin, B. Clindamycin, C. Amoxicillin- clavulanate, D. Metronidazole
D: Metronidazole
Answer: D: Metronidazole 
Explanation: Metronidazole alone is never recommended in the treatment of lung abscess, It is effective against anaerobic organism but the streptococci (Microaerophilic) will be spared which are often the component of flora causing lung abscess. Treatment regimen 1. Clindamycin- 600 mg IV TDS When fever disappear and clinical improvement is there Sta with per oral 300 mg QID 2. IV-administered b-lactam/b-lactamase combination When stable, sta oral amoxicillin-clavulanate. 3. Moxifloxacin 400 mg/d PO is as effective and well tolerated as ampicillin-sulbactam Treatment duration: 3-4 weeks or as long as 14 weeks