Probenecid and intraocular methicillin
Related Experiment Video
Updated: Oct 13, 2026
10:02
Use of Rabbit Eyes in Pharmacokinetic Studies of Intraocular Drugs
Published on: July 23, 2016
Annals of Ophthalmology
|February 1, 1981
Abstract:
Probenecid was given intravenously to rabbits in an effort to extend the intraocular longevity of intravitreal methicillin. With relatively high levels of probenecid, an insignificant elevation of half-life was obtained. Aqueous levels of methicillin were measured after intravitreal injection and were found to be adequate to inhibit penicillinase-producing S. aureus for approximately 20 hours.
Insights
Probenecid did not significantly extend the intraocular longevity of intravitreal methicillin in rabbits. However, methicillin levels remained adequate to inhibit Staphylococcus aureus for about 20 hours.
Area of Science:
- Ophthalmology
- Pharmacology
- Microbiology
Background:
- Intravitreal antibiotics are crucial for treating intraocular infections.
- Methicillin is effective against penicillinase-producing Staphylococcus aureus.
- Optimizing the intraocular drug delivery and longevity is essential for sustained therapeutic effect.
Purpose of the Study:
- To investigate the effect of probenecid on the intraocular longevity of intravitreal methicillin.
- To determine if probenecid can enhance the therapeutic duration of methicillin in the eye.
Main Methods:
- Intravenous administration of probenecid to rabbits.
- Intravitreal injection of methicillin.
- Measurement of aqueous humor methicillin levels over time.
- Assessment of methicillin's inhibitory activity against S. aureus.
Main Results:
- Probenecid administration resulted in an insignificant elevation of methicillin's half-life.
- Adequate aqueous methicillin concentrations were maintained for approximately 20 hours.
- The drug demonstrated sustained inhibitory activity against penicillinase-producing S. aureus.
Conclusions:
- Probenecid is not effective in significantly prolonging the intraocular longevity of intravitreal methicillin.
- Intravitreal methicillin provides a substantial duration of antibacterial activity against S. aureus in the aqueous humor.
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