A 50-year-old male presented with complaints of cough with expectoration, fever and malaise for 3 weeks. Patient is a chronic alcoholic and has had frequent hospitalizations in the past. On examination, Extremely poor dentition Foul smelling sputum Wheezing over the upper zone of right lung A chest x ray and a CT was conducted. Which is the most appropriate therapy to be given in the above condition: -

This is a case of right lung abscess in view of the signs and symptoms and history of alcoholism and aspirations. Therapy is given for upper airway anaerobes. For primary lung abscesses: - Clindamycin is approved. Metronidazole is not effective as a single agent. Aztreonam has predominant activity against Gram-negative bacteria. Penicillin can't be given because oral anaerobes can produce beta-lactamases. The X-ray and the CT shows a cavitatory lesion in the right lung with an air-fluid level - likely a lung abscess.