
Factors associated with failure to complete isoniazid therapy for latent tuberculosis infection in children and adolescents. Completion of the recommended 9-month course of isoniazid to treat latent tuberculosis infection in children remains poor and is often affected by adverse effects, including hepatitis, to medication. We evaluated the frequency of isoniazid therapy completion and factors associated with failure to complete therapy in patients aged 0-18 years. We performed a retrospective review of medical records for patients aged 0-18 years who were referred for isoniazid therapy between January 2005 and August 2011 at 2 California county sites: a public health department and a pediatric latent tuberculosis infection clinic. Medication adherence to isoniazid therapy was measured by monthly pill count.