Isoniazid/rifampicin

Abstract

Isoniazid/rifampicin Emergence of bacterial resistanceA 21-year-old woman exhibited emergence of bacterial resistance following treatment with isoniazid and rifampicin for lymph node tuberculosis (TB).The woman had several years of history of chronic headache, for which she underwent Chiari decompression surgery in 2017. In 2019, she was diagnosed with latero-cervical lymph node TB. She was also found positive for TB in GeneXpert MTB/RIF test, without resistance to rifampicin. Subsequently, she was treated with isoniazid and rifampicin [dosages and routes not stated], along with ethambutol and pyrazinamide for 2 months. Post completion of the 2-month treatment, isoniazid and rifampicin were continued for further 10 months. After one year of treatment, the lymph nodes were noted to be disappeared. Six months after the end of the treatment, she presented with a severe headache. She underwent a cerebral CT scan, which showed a peripherally enhanced collection in the retropharyngeal area. Upon further investigation, she was diagnosed with Mycobacterium tuberculosis complex (MTC), which was found to be became resistant to rifampicin. Hence, molecular tests, i.e. GenoType MTBDRplus VER.2 and GenoType MTBDRsl VER.1 were performed to confirm the resistance to other anti-TB drugs. The MTBDRplus VER.2 showed emergence of resistance to both rifampicin and isoniazid. The molecular diagnosis was confirmed by showing epithelioid and giant cellular granulomas with caseous necrosis. An emergence of bacterial resistance following treatment with isoniazid and rifampicin was thus determined [times to reaction onset not stated].Therefore, the woman started receiving a long-term protocol consisting of 6 months of levofloxacin, linezolid, bedaquiline, cycloserine and clofazimine, and 12-14 months of levofloxacin, linezolid, clofazimine and cycloserine. During the follow-up, one month later, the anti bacillary medication was noted to be well tolerated.