"Therefore, these data show that azithromycin appears to be widely
distributed into brain tissue but not into cerebrospinal fluid or
aqueous humor of the eye."

Interesting!

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Antimicrob Agents Chemother. 1996 Mar;40(3):825-6.

     Distribution of azithromycin into brain tissue, cerebrospinal
fluid, and aqueous humor of the eye.

         * Jaruratanasirikul S,
         * Hortiwakul R,
         * Tantisarasart T,
         * Phuenpathom N,
         * Tussanasunthornwong S.

     Department of Medicine, Prince of Songkla University, Hat Yai,
Songkla, Thailand.

     To measure the concentrations of azithromycin in the central
nervous system, 20 patients with brain tumors (group I) received a
single 500-mg {*filter*}dose of azithromycin either 24, 48, 72, or 96 h prior
to the tumor removal operation and 10 patients with cataracts undergoing
surgery (group II) and 7 patients scheduled to undergo lumbar puncture
(group III) received the same dose of azithromycin 24 h prior to the
operation or procedure. Serum from all patients, brain tissue from group
I, aqueous humor from group II, and cerebrospinal fluid from group III
were assayed for azithromycin concentration. The mean concentrations of
azithromycin in brain tissue 24, 48, 72, and 96 h after administration
were 2.63 +/- 2.58, 3.64 +/- 3.81, 0.74 +/- 0.37, and 0.41 micrograms/g,
respectively. In contrast, the concentrations of azithromycin in
cerebrospinal fluid and aqueous humor of the eye were very low or
undetectable. Therefore, these data show that azithromycin appears to be
widely distributed into brain tissue but not into cerebrospinal fluid or
aqueous humor of the eye.

     PMID: 8851625 [PubMed - indexed for MEDLINE]