posted 19 March 2005 13:08               

What about the abx that pierce the blood/brain barrier?

That isn't the same as busting cysts, but do any abx do both?

posted 20 March 2005 09:52               

Here's what I have. Interestingly, this is from an MS page, and focuses on treating C. pneumoniae as a causative agent for MS.:
Partial list of antibiotics (that cross the BBB) (page was posted 8/2004, but much of the info is from 2000-- I've added some since):

OFLOXACIN (racemic mixture) a fluoroquinolone

RIFAMPIN lipophilic ----------------- (all rifamycins)

METRONIDAZOLE (Flagyl)- lipophilic [used against Bb cysts]

COTRIMOXAZOLE (Bactrim) a sulfa drug -- (all
Sulfamides)

SPARFLOXACIN (Zagam) a fluoroquinolone

Ketek —from what I’ve read, crosses the BBB only weakly. Macrolide family, 4th generation,

LEVOFLOXACIN (L isomer of Ofloxacin) a fluoroquinolone

DOXYCYCLINE (vibramycin) a tetracycline type-lipophilic.

MINOCYCLINE-a Tetracycline

GREPAFLOXACIN-

AMOXICILLIN- a penicillin type, passes BBB only weakly

Bicillin — a penicillin, passes bbb only weakly if at all; there’s some disagreement among pharacologists about this. See footnote below.

BIAXIN-a macrolide-passes BBB weakly

ZITHROMAX- a macrlide-passes BBB weakly

ERYTHROMYCIN a macrolide---passes BBB, but not as well as other antibiotics.

Tinidazole (Tindamax)— a 2005 drug ref says: Tinidazole is distributed into virtually all tissues and body fluids and also crosses the blood-brain barrier. [used against Bb cysts]

???Plaquenil? - did not find info on plaquenil and BBB. [Used against cysts]

Quinolones

Generation III cephlasporins (see http://www.infagra.com/cephalosporins.html )

I'm editing to add this footnote on pencillin : There is a lot of disagreement, it seems, about how well the penicillins penetrate the bbb. It apparently crosses well in the presence of inflammation of brain tissue; crosses more effectively for IM or IV administration; and some researchers say it crosses better than is generally thought, but it's also transported out quickly from the CSF to the blood.

Does NOT cross the bbb:
- Tetracycline
- Generation I cephlasporins (Generation II cross weakly)
- Penicillin (???See footnote about this, above)

Interesting general info on the different types of abx, where they come from, what they specifically do, at the Todar site http://www.textbookofbacteriology.net/. Scroll to get there -- starts about 2 screens down.

And here’s a factoid: The blood-brain barrier is an exclusive component of the endothelium of the over 400 miles of cerebral capillaries, where tight junctions prevent substances in the blood from crossing between cells and into the brain.

----------------------
And from PubMed — discussing meningitis, but interesting re abx penetration of BBB:
Clin Infect Dis. 1998 Nov;27(5):1117-27, quiz 1128-9. Related Articles, Links

Antibiotic pharmacodynamics in cerebrospinal fluid.

Lutsar I, McCracken GH Jr, Friedland IR.

Department of Pediatrics, University of Texas, Southwestern Medical Center, Dallas, USA.

The CSF half-lives of lipophilic agents, such as quinolones, are similar to those in serum and peak concentrations in CSF are achieved relatively quickly. In contrast, the pharmacokinetics of hydrophilic agents (beta-lactams and vancomycin) in CSF often differ from those in serum.

In particular, the half-lives of these agents in CSF tend to be extended, and the time to achieve peak concentrations in CSF is delayed. Hydrophilic antibiotics, such as beta-lactams, penetrate poorly through the BBB, but CSF penetration is significantly increased in the presence of inflammation. In contrast, lipophilic antibiotics, such as quinolones, enter the CSF more efficiently and their penetration is not inflammation dependent. The pharmacodynamic properties of antibiotics in CSF are generally similar to those in other body sites; beta-lactam agents and vancomycin are time-dependent, whereas the quinolones and aminoglycosides are concentration-dependent.

However, a notable difference from infections in other sites is that quinolones have a short PAE in CSF and need to continually exceed the MBC for maximal effectiveness. Thus, in CSF, quinolones demonstrate features of both concentration-dependency and time-dependency, evidence that the AUC/MBC is an important predictor of effectiveness.

With the exception of quinolones, many antibiotics appear to have prolonged sub-MIC effects and longer half-lives in CSF than in serum, suggesting that dosing intervals longer than those used traditionally would be effective in meningitis. However, this requires clinical verification.

posted 21 March 2005 08:02               

Suprax will also penetrate it as will Roxythromycin (Rulid). But Roxythromycin is not available in the U.S.

I remember reading a note that was posted year a while back about how someone was feeling dramatically better after being put on a combination of Zithromax and Mepron.

posted 18 April 2005 10:15               

Widely distributed into body tissues and fluids including pleural fluid, bronchial secretions, sputum, ascitic fluid, synovial fluid, aqueous and vitreous humor, and prostatic fluid. Better CSF penetration compared to tetracycline (26% of serum level attained).