Congenital tuberculosis (TB) use of second-line medication and therapeutic drug monitoring

Abstract

Objectives: Congenital tuberculosis (TB) is a rare complication of TB during pregnancy. Diagnosis and treatment are challenging, especially in premature infants due to limited data on drug dosing.

Case presentation: A male infant was born at 33 weeks gestational age to a mother who was hospitalized with respiratory illness and diagnosed with TB after delivery. The diagnosis was based on the presence of granulomas and mycobacteria in the placenta, positive mycobacterium TB PCR in gastric aspirate, and growth of MTB from gastric aspirate and bronchoalveolar lavage cultures. Treatment started initially with isoniazid, rifampin, pyrazinamide, and ethambutol. The patient's clinical course was complicated with ongoing respiratory distress and abdominal distension which raise the possibilities of drug resistance, but sensitivity was confirmed by PCR, or malabsorption of the medications due to concerns of abdominal TB. Isoniazid and rifampin doses needed to be adjusted due to low serum drug levels. Ethambutol was replaced by Levofloxacin, due to concerns about drug toxicity and unreliable therapeutic levels, but still there was no clinical improvement which raised the possibility of paradoxical reaction to the treatment, so we started the patient on prednisone for one month and tapered over two weeks. From age two months the patient showed progressive improvement and has by now completed 12 months of therapy with good clinical outcome.

Conclusions: Therapeutic drug monitoring is important for adjusting medication dosage in premature infants due to limited experience in this age group.

Keywords: congenital; drug-monitoring; mycobacteria; tuberculosis.

Figure 1:

CT scan lungs and airways of the infant, showing diffuse nodular parenchymal opacities bilaterally, most significantly involving the right hemithorax September 2020.