Which medication is NOT an appropriate initial intervention for sinusitis?

In the treatment of sinusitis, particularly bacterial sinusitis, the initial management often involves the use of antibiotics to combat the infection. Amoxicillin-Clavulanate is a common first-line treatment due to its efficacy against the types of bacteria most frequently associated with sinus infections. Cephalexin and Sulfamethoxazole-trimethoprim can also be used and are considered appropriate options for initial therapy due to their spectrum of activity against the pathogens responsible for sinusitis.

Erythromycin, while an antibiotic, is not typically recommended as an initial treatment for sinusitis. This is due to its limited spectrum of action against the most common pathogens involved in this condition, as well as the higher resistance rates among these bacteria. Therefore, for an effective initial intervention, it's crucial to select antibiotics that target the common bacterial causes, making erythromycin the least appropriate choice in this context.