Which two antibacterial medications are combined in Pediazole and why is this drug appropriate for treating acute otitis media?
The correct answer and explanation is :
Correct Answer:
Pediazole is a combination of erythromycin (a macrolide antibiotic) and sulfisoxazole (a sulfonamide antibiotic).
300-Word Explanation:
Pediazole is an oral suspension that combines two antibacterial agents: erythromycin ethylsuccinate and sulfisoxazole acetyl. Each of these antibiotics works through a different mechanism of action, which enhances the medication’s overall effectiveness, especially in pediatric infections such as acute otitis media (AOM).
Erythromycin is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit. This prevents bacteria from producing the proteins necessary for growth and replication. It is particularly effective against Gram-positive bacteria and some Gram-negative organisms.
Sulfisoxazole is a sulfonamide that inhibits the synthesis of folic acid in bacteria, which is essential for DNA replication and cell division. It works by blocking the enzyme dihydropteroate synthase, which is not found in humans, making it a safe and targeted bacterial inhibitor.
The combination of these two agents offers a broad-spectrum antimicrobial coverage, which is especially important in treating acute otitis media caused by organisms such as:
- Haemophilus influenzae
- Streptococcus pneumoniae
- Moraxella catarrhalis
These bacteria are commonly implicated in pediatric ear infections. H. influenzae and M. catarrhalis often produce beta-lactamase, making them resistant to penicillin-type drugs. The macrolide-sulfonamide combination in Pediazole is effective against these resistant strains.
Pediazole is especially useful in children with penicillin allergies, as it provides an alternative treatment that does not belong to the beta-lactam class of antibiotics.
Additionally, the dual mechanism of action helps prevent the development of resistance, as bacteria would need to simultaneously adapt to both protein and folic acid synthesis inhibition.
In summary, Pediazole is appropriate for treating acute otitis media because it offers broad-spectrum coverage, combats beta-lactamase–producing organisms, and provides an alternative for penicillin-allergic patients.