People with Lyme arthritis treated with intravenous antibiotics or two months of oral antibiotics who continue to have joint swelling two months after treatment and have negative PCR test for Borrelia DNA in the synovial fluid are said to have antibiotic-refractory Lyme arthritis; this is more common after infection by certain Borrelia strains in people with certain genetic and immunologic characteristics. Antibiotic-refractory Lyme arthritis may be symptomatically treated with NSAIDs, disease-modifying antirheumatic drugs (DMARDs), or arthroscopic synovectomy. Physical therapy is recommended for adults after resolution of Lyme arthritis.People receiving treatment should be advised that reinfection is possible and how to prevent it. Prognosis
Lyme diseases typical first sign, the erythema migrans (EM) rash, resolves within several weeks even without treatment. However, in untreated people, the infection often disseminates to the nervous system, heart, or joints, possibly causing permanent damage to body tissues.People who receive recommended antibiotic treatment within several days of appearance of an initial EM rash have the best prospects. Recovery may not be total or immediate. The percentage of people achieving full recovery in the United States increases from about 64–71% at end of treatment for EM rash to about 84–90% after 30 months; higher percentages are reported in Europe. Treatment failure, i.e. persistence of original or appearance of new signs of the disease, occurs only in a few people. Remaining people are considered cured but continue to experience subjective symptoms, e.g. joint or muscle pains or fatigue.
The oral doses must be double the intravenous (IV) mesna dose due to bioavailability issues. The oral preparation allows patients to leave the hospital sooner, instead of staying four to five days for all the IV mesna infusions. Mechanism of action
Mesna reduces the toxicity of urotoxic compounds that may form after chemotherapy administration. Mesna is a water-soluble compound with antioxidant properties, and is given concomitantly with the chemotherapeutic agents cyclophosphamide and ifosfamide. Mesna concentrates in the bladder where acrolein accumulates after administration of chemotherapy and through a Michael addition, forms a conjugate with acrolein and other urotoxic metabolites. This conjugation reaction inactivates the urotoxic compounds to harmless metabolites. The metabolites are then excreted in the urine. Names
It is marketed by Baxter as Uromitexan and Mesnex. The name of the substance is an acronym for 2-mercaptoethane sulfonate Na (Na being the chemical symbol for sodium). See also
Coenzyme M—a coenzyme with the same structure used by methanogenic bacteria

References
External links
BC Cancer Agency
NIH/MedlinePlus patient information
Mesna at the US National Library of Medicine Medical Subject Headings (MeSH)