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)