TB retreatment regimen has poor long-term outcomes, study says

According to a study conducted by Edward Jones López of Boston University Medical School and his colleagues, the standard retreatment regimen for tuberculosis has low response rates to treatment and has poor long-term outcomes in particular patient subgroups.

The subgroups include those infected with both HIV and multi-drug resistant TB. The research indicates that the standard retreatment approach as it is implemented in low and middle income settings with a high prevalence of HIV is inadequate, Medical News Today reports.

The standardized five drug retreatment regimen, including the drugs streptomycin, isoniazid, ethambutol, rifampicin and pyrazinamide, is recommended by the World Health Organization. This retreatment method, the report says, has not been properly evaluated in randomized clinical trials or prospective studies. The regimen was recommended before widespread MDR-TB.

Jones López's study found that 20 percent of HIV-uninfected and 26 percent of HIV-infected patients had an unsuccessful treatment outcome. All patients with MDR-TB had unsuccessful outcomes to treatment.

"The recommended regimen for retreatment TB in Uganda yields an unacceptable proportion of unsuccessful outcomes,” the report says, according to Medical News Today. “There is a need to evaluate new treatment strategies in these patients. Clinical trials of new approaches to retreatment TB in areas heavily affected by HIV and TB should be a priority."

Jerome Amir Singh of the University of Kwazulu-Natal, Durban, South Africa, wrote an accompanying perspective to the study, discussing its ethical context. Despite ethical dilemmas like introducing an efficacious standard of care in a setting where this care wouldn’t otherwise be available, he says that the study is important.

"The Uganda study has undoubtedly addressed an important knowledge gap in science,” Singh said, according to Medical News Today. “It will hopefully herald revisions to Uganda's TB treatment program and inspire similar reforms elsewhere. Equally significant, the study catalyzed the provision of second-line TB therapy in that country. In so doing, the study has undoubtedly left the local population better off compared to before its commencement. These two factors, alone, make the Uganda study ethically defensible."