Ihab Weheba, Sarah K Brode, Melissa Richard-Greenblatt, Natasha F Sabur
This case demonstrates successful use of the all-oral BPaLM regimen in a patient with prior gastrectomy when supported by therapeutic drug monitoring. Evaluating drug exposure may help optimize treatment outcomes in patients at risk for drug malabsorption.
BACKGROUND: Patients with a history of gastrectomy are at increased risk of developing pulmonary tuberculosis due to nutritional deficiencies and potential immune impairment. Altered gastrointestinal anatomy can affect oral drug absorption and treatment pharmacokinetics, making management of drug-resistant tuberculosis in this population challenging.
CASE SUMMARY: We describe a case of a woman with a history of gastric adenocarcinoma treated with chemotherapy, followed by near-total gastrectomy and Roux-en-Y reconstruction, who subsequently developed multidrug-resistant pulmonary tuberculosis. A biopsy of a pulmonary nodule was sent for culture and grew Mycobacterium tuberculosis complex. Phenotypic drug susceptibility testing could not be performed due to poor growth; however, a line probe assay performed on the isolate identified resistance to rifampin and isoniazid. The patient was treated with the all-oral bedaquiline, pretomanid, linezolid, and moxifloxacin (BPaLM) regimen. Due to concerns regarding impaired drug absorption following gastrectomy, therapeutic drug monitoring was performed to guide dosing. Therapeutic drug levels were ultimately achieved, and sputum culture conversion occurred after 5 weeks of effective therapy. The patient successfully completed the 26-week regimen with sustained microbiologic cure.
CONCLUSION: This case demonstrates successful use of the all-oral BPaLM regimen in a patient with prior gastrectomy when supported by therapeutic drug monitoring. Evaluating drug exposure may help optimize treatment outcomes in patients at risk for drug malabsorption.