What are the primary intravenous antibiotics used for the treatment of orbital cellulitis?

The treatment of orbital cellulitis often requires the use of broad-spectrum intravenous antibiotics to effectively target the common pathogens associated with the condition, which include streptococci, staphylococci, and occasionally anaerobic bacteria. The combination of vancomycin and clindamycin is particularly effective in this context.

Vancomycin is a key agent for covering methicillin-resistant Staphylococcus aureus (MRSA), which is a challenging pathogen often implicated in skin and soft tissue infections that can lead to orbital cellulitis. Clindamycin provides excellent coverage for anaerobes and also has activity against certain strains of streptococci and staphylococci, further broadening the spectrum of treatment and addressing the polymicrobial nature of infections that can occur in the orbital space.

This combination not only targets a wide range of bacteria but also is well-supported by clinical guidelines in pediatric patients with orbital cellulitis, making it the first line of therapy in this serious condition. In contrast, the other options listed do not provide the same level of coverage needed for the infectious agents primarily responsible for orbital cellulitis.