Cerebrospinal fluid concentrations of ethionamide in children with tuberculous meningitis.

Cerebrospinal fluid ethionamide concentrations were determined in 18 children (median age 26.5 months) with tuberculous meningitis complicated by raised intracranial pressure. Lumbar spinal fluid specimens were obtained before and after weekly hour-long monitoring of intracranial pressure. Thirty-five paired and four single specimens were evaluated. A dosage schedule of 15 mg/kg was used on 26 occasions, and a spinal fluid ethionamide concentration of 2.5 micrograms/ml, the in vitro minimal inhibitory concentration for Mycobacterium tuberculosis, was exceeded on only seven occasions (27%). A dosage of 20 mg/kg was administered on 13 occasions, and in only two instances (15%) was a concentration of 2.5 micrograms/ml not achieved. Ethionamide in a single daily dosage of 20 mg/kg should be considered for the initial treatment of tuberculous meningitis when the presence of isoniazid-resistant M. tuberculosis cannot be excluded.