The drugs most likely to be causing the reaction should be tested as late as possible (and possibly need not be tested at all). This avoids rechallenging patients with a drug to which they have already had a (possibly) dangerous adverse reaction.A similar scheme may be used for other adverse effects (such as fever and rash), using similar principles. Dysbiosis caused by HRZE antibiotic treatment
Tuberculosis treatment results in changes to the structure of the gut microbiome both during and after treatment in mice and humans. It is currently unknown what the long term effects of this dysbiosis are on systemic immunity. Deviations from the standard regimen
There is evidence supporting some deviations from the standard regimen when treating pulmonary TB. Sputum culture-positive patients who are smear-negative at the start of treatment do well with only 4 months of treatment (this has not been validated for HIV-positive patients); sputum culture-negative patients do well on only 3 months of treatment (possibly because some of these patients never had TB at all). It is unwise to treat patients for only three or four months, but all TB physicians will have patients who stop their treatment early (for whatever reason), and it can be reassuring to know that sometimes retreatment is unnecessary. Elderly patients who are already taking a large number of tablets may be offered 9HR, omitting PZA which is the bulkiest part of the regimen. It may not always be necessary to treat with four drugs from the beginning.
It is prudent to advise all women of child-bearing age to avoid getting pregnant until TB treatment is completed. Aminoglycosides (STM, capreomycin, amikacin) should be used with caution in pregnancy, because they may cause deafness in the unborn child. The attending physician must weigh the benefits of treating the mother against the potential harm to the baby, and good outcomes have been reported in children whose mothers were treated with aminoglycosides. Experience in Peru shows that treatment for MDR-TB is not a reason to recommend termination of pregnancy, and that good outcomes are possible. Kidney disease
People with kidney failure have a 10 to 30-fold increase in risk of getting TB. People with kidney disease who are being given immunosuppressive medications or are being considered for transplant should be considered for treatment of latent tuberculosis if appropriate. Aminoglycosides (STM, capreomycin and amikacin) should be avoided in patients with mild to severe kidney problems because of the increased risk of damage to the kidneys. If the use of aminoglycosides cannot be avoided (e.g., in treating drug-resistant TB) then serum levels must be closely monitored and the patient warned to report any side-effects (deafness in particular). If a person has end-stage kidney disease and has no useful remaining kidney function, then aminoglycosides can be used, but only if drug levels can be easily measured (often only amikacin levels can be measured). In mild kidney impairment, no change needs to be made in dosing any of the other drugs routinely used in the treatment of TB.