Ocular pharmacokinetics of orally administered azithromycin in rabbits.
Azithromycin was orally administered to Dutch-belted rabbits following extracapsular lens extraction in one eye. At various times the animals were sacrificed, and serum and ocular tissues were obtained for drug level determination by HPLC-EC. Following a single dose, peak levels of drug in ocular tissues were measured within 8 hours (cornea > 0.5 micrograms/g [15mg/kg]; > 1.5 micrograms/g [3Omg/kg]). Highest levels were obtained in iris and ciliary body ( > 15 micrograms). Measurable tissue levels persisted for at least 120 hours. Trough levels increased proportionately during drug multiple dose administration. Five days following five daily 15mg/kg doses, corneal levels exceeded 0.5 micrograms/g, and iris and ciliary levels were higher than 15 micrograms/g. Aqueous humor and serum levels were equivalent. Vitreous humor levels, though higher than aqueous humor, were consistently < 1 microgram/ml. Extracapsular cataract extraction did not significantly affect drug uptake.
O'Day
D M
DM
Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee.
Head
W S
WS
Foulds
G
G
Robinson
R D
RD
Williams
T E
TE
Ferraina
R A
RA
D000284:Administration, Oral; D000818:Animals; D000869:Anterior Eye Segment / Q000378:metabolism; D017963:Azithromycin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D001682:Biological Availability; D002387:Cataract Extraction; D002851:Chromatography, High Pressure Liquid; D005123:Eye / Q000378:metabolism*; D006207:Half-Life; D011817:Rabbits; D014018:Tissue Distribution; D014822:Vitreous Body / Q000378:metabolism
D017963:Azithromycin