The kinetics of anterior chamber ofloxacin penetration

Area of Science:

• Ophthalmology
• Pharmacology

Background:

• Antibiotic prophylaxis is crucial in ophthalmic surgery to prevent postoperative infections.
• Topical fluoroquinolones are commonly used for perioperative antibiotic coverage in eye surgery.

Purpose of the Study:

• To determine the aqueous humor concentration of ofloxacin following a specific topical dosing regimen before cataract surgery.
• To investigate the correlation between the timing of the last ofloxacin dose and achieved aqueous humor levels.

Main Methods:

• Thirty-five patients undergoing cataract surgery received topical ofloxacin 0.3% (5 doses daily before surgery, 5 doses immediately before).
• Aqueous humor samples were collected 30-150 minutes after the final dose.
• Ofloxacin concentrations were measured using validated analytical methods.

Main Results:

• The mean aqueous ofloxacin concentration was 793 +/- 516 ng/ml.
• A significant positive correlation was observed between the time elapsed since the last dose and aqueous ofloxacin concentration (r = 0.39, p = 0.025).
• Patients with the last dose >1 hour before sampling had higher concentrations (957 ng/ml) compared to those sampled earlier (554 ng/ml).

Conclusions:

• Topical ofloxacin 0.3% achieves substantial intraocular penetration relevant for perioperative prophylaxis.
• Dosing timing significantly influences ofloxacin concentration in the aqueous humor, with higher levels achieved when the last dose is administered at least 1 hour prior to surgery.
• Maximal aqueous concentrations are estimated to occur around 2 hours post-administration.