For keratitis abrasions/erosions, fluoroquinolones should be dosed with what frequency?

• A. BID
• B. QID
• C. QD
• D. TID

Answer: (B)

Dosing four times daily helps keep drug levels on the damaged corneal surface consistently above the level needed to prevent infection while the epithelium heals. When the corneal epithelium is compromised, tear turnover and washout can rapidly reduce antibiotic concentration, so more frequent dosing is needed to maintain therapeutic levels. This frequency provides solid coverage without the extremes of hourly dosing that would be reserved for more severe ulcers. If there’s a higher risk of infection (for example, contact lens wear or suspected Pseudomonas involvement), choose a fluoroquinolone with good anti-Pseudomonal activity and adhere to the four-times-daily schedule to ensure ongoing protection during healing.