By comparison, the tetracycline antibiotic minocycline penetrates significantly better into the CSF and meninges.Doxycycline metabolism is negligible. It is actively excreted into the gut (in part via the gallbladder, in part directly from blood vessels), where some of it is inactivated by forming chelates. About 40% are eliminated via the kidneys, much less in people with end-stage kidney disease. The biological half-life is 18 to 22 hours (16±6 hours according to another source) in healthy people, slightly longer in those with end-stage kidney disease, and significantly longer in those with liver disease. Chemistry
Expired tetracyclines or tetracyclines allowed to stand at a pH less than 2 are reported to be nephrotoxic due to the formation of a degradation product, anhydro-4-epitetracycline causing Fanconi syndrome. In the case of doxycycline, the absence of a hydroxyl group in C-6 prevents the formation of the nephrotoxic compound. Nevertheless, tetracyclines and doxycycline itself have to be taken with caution in patients with kidney injury, as they can worsen azotemia due to catabolic effects. Chemical properties
Doxycycline, doxycycline monohydrate and doxycycline hyclate are yellow, crystalline powders with a bitter taste.
Marburg acute multiple sclerosis, also known as Marburg multiple sclerosis or acute fulminant multiple sclerosis, is considered one of the multiple sclerosis borderline diseases, which is a collection of diseases classified by some as MS variants and by others as different diseases. Other diseases in this group are neuromyelitis optica (NMO), Balo concentric sclerosis, and Schilders disease. The graver course is one form of malignant multiple sclerosis, with patients reaching a significant level of disability in less than five years from their first symptoms, often in a matter of months.Sometimes Marburg MS is considered a synonym for tumefactive MS, but not for all authors. Pathogenesis
Marburg MS has been reported to be closer to anti-MOG associated ADEM than to standard MS It has been reported to appear sometimes post-partum

MOG antibody‐associated demyelinating pseudotumor
Some anti-MOG cases satisfy the MS requirements (lesions disseminated in time and space) and are therefore traditionally considered MS cases. After the discovery of the anti-MOG disease this classification is into revision. Diagnosis
It took its name from Otto Marburg. It can be diagnosed in vivo with an MRI scan. If Marburg disease occurs in the form of a single large lesion, it can be radiologically indistinguishable from a brain tumor or abscess. It is usually lethal, but it has been found to be responsive to Mitoxantrone and Alemtuzumab, and it has also been responsive to autologous stem cell transplantation. Recent evidence shows that Marburgs presents a heterogeneous response to medication, as does standard MS.