A 28-year-old woman with a 2-year history of chronic suppurative otitis media with central perforation presents with persistent ear discharge despite 3 months of topical ciprofloxacin drops. Audiometry shows moderate conductive hearing loss. She is being considered for tympanoplasty. What is the preferred systemic antibiotic regimen to eradicate infection before surgery?

## Systemic Antibiotic Choice for Refractory CSOM **Key Point:** Oral fluoroquinolones (ciprofloxacin or ofloxacin) are the preferred systemic agents for CSOM when topical therapy fails or before surgical intervention, because they achieve excellent middle ear penetration and cover Pseudomonas aeruginosa. ## Rationale for Ciprofloxacin ### Pharmacokinetic Advantage - Achieves high concentrations in middle ear mucosa and bone - Excellent intracellular penetration — critical for biofilm-embedded organisms - Achieves therapeutic levels in infected bone and granulation tissue ### Microbiological Coverage - Covers Pseudomonas aeruginosa (the most common pathogen in refractory CSOM) - Also active against S. aureus, gram-negative rods, and anaerobes - Effective against biofilm-producing organisms that resist beta-lactams ### Pre-Surgical Indication - Reduces bacterial load before tympanoplasty - Decreases risk of graft failure due to infection - Standard protocol: 2–3 weeks before planned surgery ## Comparison of Systemic Agents in CSOM | Agent | Middle Ear Penetration | P. aeruginosa Coverage | Biofilm Efficacy | Preferred? | | --- | --- | --- | --- | --- | | **Ciprofloxacin** | **Excellent** | **Yes** | **Yes** | **Yes** | | Amoxicillin-clavulanate | Moderate | No | Poor | No (limited spectrum) | | Gentamicin (IM) | Poor | Yes | No | No (ototoxic, poor penetration) | | Cephalexin | Moderate | No | Moderate | No (no Pseudomonas coverage) | **High-Yield:** Fluoroquinolones are the only oral antibiotics with reliable Pseudomonas coverage and excellent bone/tissue penetration — essential for CSOM management. **Warning:** Aminoglycosides (gentamicin, tobramycin) should be avoided systemically in CSOM because they do not penetrate infected bone well and carry risk of ototoxicity, especially in patients with pre-existing hearing loss. **Clinical Pearl:** Duration is typically 2–3 weeks before tympanoplasty. Some surgeons prefer a 2-week course of ciprofloxacin followed by topical drops until discharge ceases.