I'm curious about how effective it is at crossing the blood brain barrier with a 800 mg/d dose.

so no one knows yet how it affects the tissues long term, especially if taken for longer than the 10 period they tested it on....

we'll just have to wait and see. It also has not been approved for use on children yet, because their receptors for this particular medication is not fully developed yet, but as i understand some kids are doing great on it..so go figure...

I'm a nurse, and I did not take ketek because of what my pharmacist told me about it not being proven to be safe for longer than 10 days...I know we take chances every day, but the abx we stay on usually have longer track records ..this one is new...I didn't want to be a guinea pig...

but I hear it's doing goodthings for people..so I'm keeping my fingers crossed...it just won't be me trying it ....

The Ketolides: a critical review, Dec 2002
Ketolides such as telithromycin display excellent pharmacokinetics allowing once daily dose administration and extensive tissue distribution relative to serum. Evidence suggests the ketolides are primarily metabolised in the liver and that elimination is by a combination of biliary, hepatic and urinary excretion.

Pharmacodynamically, ketolides display an element of concentration dependent killing unlike macrolides which are considered time dependent killers.

This article offers the best ketolide tissue-concentration info vis-a-vis borelliosis I could find:

Comparison of In Vitro Activities of Ketolides, Macrolides, and an Azalide against the Spirochete Borrelia burgdorferi, Jan 2004
Classical macrolides and azalides frequently fail in the therapy of early LD (7, 14, 17, 26), and clinical relapse has been observed following conclusion of treatment (14, 17, 26). Moreover, it has been speculated that resistance may develop in borreliae preexposed to erythromycin owing to resistant subpopulations (25).

Based upon our findings, however, the ketolides were superior in vitro on a micrograms-per-milliliter basis when tested alongside classical macrolides under identical test conditions in BSK. This is further substantiated by our time-kill experiments (Fig. 1A to C) and by electron microscopy.

Moreover, maximum concentrations of ketolides in plasma after regular oral dosage (1, 6, 27) are 90 to 270 times higher than the MIC90s against borreliae in our study, and tissue concentrations exceed by 10-fold the maximum plasma concentrations of both drugs in controls (1, 6, 27). Therefore, the potential role of ketolides in the treatment of LD merits further evaluation.

The regular oral dosage referred to in that study is 800mg/d, so it looks like you're right on target, Mathias. (For what that's worth. )

Please holler if you find more info on this; I'm considering switching from my cephalosporin to a ketolide like Ketek.

that was the concern..not it's effectiveness..

Where did you find the 2ug/ml figure? The table of findings in the study I linked above rates the ketolides as the most potent borrelicide on a ug/ml basis - from 0.06ug/ml to 0.2ug/ml to kill 90% of the isolates.

Is that just blood concentration (and in vitro), and not necessarily reflective of tissue penetration? (I'd love to learn more, just starting to research this stuff).

peanut