Final answer:
Amoxicillin is the first-line empiric treatment for acute bacterial sinusitis, due to its effectiveness in the early stages of infection and despite concerns about resistance.
Step-by-step explanation:
The first-line empiric treatment for acute bacterial sinusitis is Amoxicillin. This antibiotic choice is effective during the early stages of an infection. While high-dose amoxicillin is the preferred treatment, there are growing concerns about resistance, and alternatives such as macrolides and cephalosporins, like azithromycin and ceftriaxone, may also be used if necessary.
Especially in areas where pneumococcal and H. influenzae type B vaccine coverage is high, amoxicillin remains the first-line due to its effectiveness against the common causative organisms of acute bacterial sinusitis, such as S. pneumoniae and H. influenzae. Vaccination against pneumococcal bacteria and influenza can also reduce the incidence of this condition, as viral infections can predispose patients to secondary bacterial infections.