I'm posting this abstract because it underlines the complexities of trying to compare different antibioticsi [1]. Please note it's limitations in that it is cell culture, and doesn't address issues like absorbtion through the intestinal tract, penetration into larger tissue masses, and so on. But, it illustrates that even while some antiotics may have better absorbtion into particular cells (phagocytes and epithelial cells which are the common targets for Cpni [2]), others may have more anti-chlamydial effect: "Intracellulari [3] accumulation of telithromycin was lower than that observed for minocycline, but telithromycin demonstrated substantially more potent antichlamydial activity." Note that clarithromycin (Biaxin) was found to have similar concentration levels in the cells. It would be good to read the text to look at comparison in lethal versus inhibitory concentrations.

 

J Chemother. [4] 2008 Aug;20(4):428-30 [5]

The intracellular accumulation of phagocytic and epithelial cells and the inhibitory effect on Chlamydophila (Chlamydia) pneumoniae of telithromycin and comparator antimicrobials.

Yamazaki T [6], Takemura H [7], Inoue M [8], Ogawa M [9], Ando S [10], Sato K [11], Kishimoto T [12].

First Department of Virology, National Institute of Infectious Diseasesi [13], Tokyo, Japan. benyama@saitama-med.ac.jp [14]

The intracellular accumulation of telithromycin was measured and compared with ciprofloxacin, clarithromycin, minocycline and erythromycin. The activities of telithromycin, clarithromycin and minocycline against Chlamydophila (Chlamydia) pneumoniae were compared in an intracellular killing assay. Maximal telithromycin accumulation (mean intracellular/extracellular concentration ratio) ranged from 6.7 (A549 lung epithelial cells) to 11.8 (THP-1 monocytic cells). This ratio was similar to that of clarithromycin, but less than for minocycline. Minimum inhibitory and minimum lethal telithromycin concentrations against six clinical strains of C. pneumoniae were <0.015-0.03 mg/L and 0.03-0.06 mg/L, respectively, which were lower than those found for minocycline. These results show that telithromycin accumulates rapidly into epithelial cells, similar to previously reported results for phagocytic cells. Intracellular accumulation of telithromycin was lower than that observed for minocycline, but telithromycin demonstrated substantially more potent antichlamydial activity.

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CAPi [15]i [15] for Cpni [2] 11/04. Dx: 25yrs CFSi [16]i [16] & FMSi [17]i [17]. Currently: 150mg BID Roxithromycin, Doxycycline 100mg BID, Tinii [18]i [18] 1000mg/day pulses; Vit D2000 units, T4 & T3