Which antibiotic provides the best coverage in sinusitis when gram-negative organisms are suspected?

Levofloxacin is an antibiotic that belongs to the fluoroquinolone class and is particularly effective against a range of gram-negative organisms, which include bacteria commonly associated with sinusitis, such as Haemophilus influenzae and Moraxella catarrhalis. This makes it a suitable choice when there is a suspicion of gram-negative involvement in a sinus infection.

In comparison, Penicillin V and Amoxicillin are primarily effective against gram-positive bacteria and some limited gram-negative bacteria. While Amoxicillin does provide some coverage for certain organisms linked to sinusitis, it may not be sufficient if a broader spectrum is required. Clindamycin is effective against anaerobic bacteria and some gram-positive organisms but has limited activity against gram-negative pathogens, making it less ideal for suspected gram-negative sinusitis.

Thus, levofloxacin’s broad-spectrum activity and its strong coverage against the gram-negative bacteria associated with sinusitis make it the best choice in this scenario.