Comparison of bacterial organisms from otic exudate and ear tissue from the middle ear of untreated and enrofloxacin-treated dogs with chronic end-stage otitis

Plasma and ocular prednisolone disposition after oral treatment in cats

Objective. To evaluate the plasma and aqueous humor disposition of prednisolone after oral administration in cats. Methods. Six cats were administered with a single oral dose of prednisolone (10 mg). Blood and aqueous humor samples were serially collected after drug administration. Prednisolone concentrations in plasma and aqueous humor were measured at 0.25, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, and 5.0 h after administration by a high-performance liquid chromatographic analytical method developed and validated for this purpose. Results. Mean ± standard error (SE) of maximum plasma prednisolone concentration (300.8 ± 67.3 ng/mL) was reached at 1 h after administration. Prednisolone was distributed to the aqueous humor reaching a mean peak concentration of 100.9 ± 25.5 ng/mL at 1.25 h after administration. The mean ± SE systemic and aqueous humor exposure (AUC) was 553.3 ± 120.0 ng∗h/mL and 378.8 ± 64.9 ng∗h/mL, respectively. A high AUC_{aqueous humor}/AUC_plasma ratio was observed (0.68 ± 0.13). The mean half-life time of elimination in plasma and aqueous humor was 0.87 ± 0.16 h and 2.25 ± 0.44 h, respectively. Clinical Significance. The observed high ratio between aqueous humor and plasma prednisolone concentrations indicates that extensive penetration of prednisolone to the anterior segment of the eye may occur. This is the first step that contributes to the optimization of the pharmacological therapeutics for the clinical treatment of uveitis.

Otitis Techniques to Improve Practice

Successful management of otitis externa requires recognition of changes in the anatomy and physiology of the external and middle ear, as well as the adequate tools and examinations to detect changes from normal. Otoscopy and methods for assessing the normalcy of the tympanum, collection of samples for cytologic evaluation or culture, and myringotomy are diagnostic techniques important in practice. Treatment tubes and intralesional triamcinolone injections are techniques that improve the response in some cases.