Q. A 67-year-old man with a 40-pack-year smoking history presents to the clinic with increased shortness of breath and a productive cough for the past 5 days. He has a known diagnosis of chronic obstructive pulmonary disease (COPD) and has been stable on his inhaler medications until this recent exacerbation. His temperature is 38.4°C (101.1°F), respiratory rate is 22 breaths/minute, and oxygen saturation is 92% on room air. Physical examination reveals diffuse wheezing and decreased breath sounds in the right lower lung zone. A chest x-ray reveals no evidence of consolidation or pneumothorax. Sputum cultures are sent, and while awaiting results, the decision is made to start antibiotics. Which antibiotic would be most appropriate to initiate in this patient to cover both Streptococcus pneumoniae and H. influenzae?