What is the dosage for these drugs to cross the BBB?

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Traneboy
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Date Joined Sep 2017
Total Posts : 96
   Posted 12/25/2017 12:38 PM (GMT -6)   
I know that Zithromax crosses the BBB at 500 mg and Doxy crosses it at 400 mg. Correct me if i'm wrong.
Also, can Doxy cross the BBB if i take 200 mg in the morning and 200 mg before bed? Or it needs to be 400 mg right away, else it won't work?

Girlie
Forum Moderator


Date Joined May 2014
Total Posts : 32625
   Posted 12/25/2017 4:21 PM (GMT -6)   
Traneboy - I have not heard about dosage when determining blood/brain barrier penetration.
I assumed that wasn't an issue.

What I do know is doxy prescribed for Lyme is usually 200 mg twice a day.
I've not seen it prescribed 400 mg once daily.

FYI - if you didn't already know - minocycline penetration of b/b barrier is better.
Moderator, Lyme Forum
Symp started April/2013; Buhner's Lyme May 15-July24/14; Igenex pos. July 3/14
Doxy: July 4-Aug.24/14;Zithro July26-Aug24/14; Amox + Proben. Aug. 29/14;
added biaxin Sept. 26/14
Disc. amox,added Ceftin Nov. 20th.;
Disc. biaxin added Buhner bart herbs Dec/14;Jan/15 pulsing Tinda (w/ Ceftin);
Abx/herb break Apr-July/15; July-mino; Aug. added Rif;
Nov./15 mino - to biaxi

goshawk
Veteran Member


Date Joined Sep 2016
Total Posts : 2115
   Posted 12/25/2017 4:21 PM (GMT -6)   
I think it does That was the dose I took.

Traneboy
Regular Member


Date Joined Sep 2017
Total Posts : 96
   Posted 12/26/2017 2:39 AM (GMT -6)   
Minocycline is hard to find. Only way is to order online, but until it comes, there could be problems.

Girlie
Forum Moderator


Date Joined May 2014
Total Posts : 32625
   Posted 12/26/2017 2:48 AM (GMT -6)   
Traneboy said...
Minocycline is hard to find. Only way is to order online, but until it comes, there could be problems.


It's hard to find? It's not readily available in your country?

How long will it take if you order online? Shouldn't be more than a week or two?
Moderator, Lyme Forum
Symp started April/2013; Buhner's Lyme May 15-July24/14; Igenex pos. July 3/14
Doxy: July 4-Aug.24/14;Zithro July26-Aug24/14; Amox + Proben. Aug. 29/14;
added biaxin Sept. 26/14
Disc. amox,added Ceftin Nov. 20th.;
Disc. biaxin added Buhner bart herbs Dec/14;Jan/15 pulsing Tinda (w/ Ceftin);
Abx/herb break Apr-July/15; July-mino; Aug. added Rif;
Nov./15 mino - to biaxi

Spanish
Regular Member


Date Joined Sep 2017
Total Posts : 137
   Posted 12/26/2017 4:41 AM (GMT -6)   
Does any one know a reputable place to order meds online?

LymeBasics
Regular Member


Date Joined Sep 2017
Total Posts : 38
   Posted 12/26/2017 5:14 AM (GMT -6)   
Azithromycine penetrates the brain but not the spinal fluid.

Doxycycline penetrates the brain ánd the spinal fluid. Concentration of 100mg Doxy 2x daily creates 1mcg/ml after oral administration in the spinal fluid. This is close to the concentration needed to kill Borrelia. Some Borrelia strains need a slightly higher concentration of the drug to respond. Some people don't absorb it well. These can be reasons to raise the Doxycycline dosage.

Raising Doxycycline 200mg 2x daily creates a higher concentration sufficient to kill/inhibit Borrelia in the spinal fluid.

Minocycline is 2x more lipid soluble than Doxycycline and could in theory have better CSF penetration. In practise doctors see varying responses. Minocycline 100mg 2x daily supposed to be as good as Doxycycline 200mg 2x daily.

Azithromycine does not concentrate in the spinal fluid and works only inside body cells and not in the extracellular environment.

Clarithromycine is a much better drug for this application since it works in both cells and fluids. But Clarithromycine also has weak penetration into the spinal fluid. Higher dosages are used in mycobacterium meningitis. Up to 1000mg 2x daily for Clarithromycine. But this is not tolerated very well orally. 500mg 2x daily is recommended.

Rocephin 2gram IV daily is used in neuro-Borreliosis. Higher dosages of Doxycycline have been used with success according to some European studies but these are reports from those that call symptoms that do not resolve after treatment post-infectious so I don't know what to think from their report that Doxycycline worked just as good.

For co-infections minocycline, rifampin + bactrim or minocyclin, rifampin + fluoroquinolone can be used to create good intracellular coverage and penetrate brain, spinal fluid, bone(marrow) and eyes sufficiently to eradicate intracellular co-infections.

Rifampin has good CSF/CNS penetration at 600-900mg once daily. It works by peak concentration so giving it 300mg 2x daily is weaker compared to 600mg once daily.

Rifabutin is a semi-synthetic variant of Rifampin. It has long halflife and enhanced killing in serum compared to Rifampin. Better in some ways but has weaker CSF/CNS penetration.

Bactrim has good CNS/CSF penetration and works against Bartonella and stationary Borrelia forms.

Fluoroquinolone has excellent CNS/CSF penetration and works against Bartonella, Mycoplasma, Chlamydia and the higher generations have good in vitro activity against Borrelia burgdorferi spirochetes and persisters.

Post Edited (LymeBasics) : 12/26/2017 4:22:27 AM (GMT-7)


dbwilco
Regular Member


Date Joined Mar 2016
Total Posts : 263
   Posted 12/26/2017 5:15 AM (GMT -6)   
my llmd uses tetracycline at 1500 mg (2x750) as he says it crosses the BBB...i did doxy 200x2, and i think it did cross, as i had a headache for a month..but llmd tells me tetra can be given in larger dose getting across BBB...
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