A 65-year-old man presents with fever, productive cough and pleuritic chest pain. Observations: temperature 38.5°C, respiratory rate 24/min, blood pressure 132/78 mmHg, pulse 98/min, oxygen saturation 95% on air. Urea is 5.8 mmol/L, and he is fully orientated. What is the most appropriate empirical antibiotic regimen for community-acquired pneumonia managed in the community?