title: Therapeutic drug monitoring for slow response to tuberculosis treatment in a state control program, Virginia, USA.
abstract: Therapeutic drug monitoring may be useful in tuberculosis management, but programmatic implementation is understudied. We performed a retrospective cohort study to determine prevalence of lower than expected levels of isoniazid, rifampin, ethambutol, and pyrazinamide measured at time of estimated peak serum concentration. Patients were tested for serum concentration at 2 hours after medication administration. When patients were tested, 22 had concentrations lower than expected range for rifampin, 23 of 39 patients had low levels of isoniazid, and 8 of 26 patients had low levels of ethambutol; all 20 patients tested for pyrazinamide were within expected range. Over 26 months, 42 patients met criteria for slow response. Diabetes was associated with slow response (p<0.001), and persons with diabetes were more likely than persons without diabetes to have low rifampin levels (p = 0.03). Dosage adjustment of rifampin was more likely to elevate serum concentration to the target range than adjustment of isoniazid given in daily doses (p = 0.01).
authors.affiliation: Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia 22908, USA. scott.heysell@gmail.com
authors.forename: Scott K
authors.initials: SK
authors.lastname: Heysell
authors.forename: Jane L
authors.initials: JL
authors.lastname: Moore
authors.forename: Suzanne J
authors.initials: SJ
authors.lastname: Keller
authors.forename: Eric R
authors.initials: ER
authors.lastname: Houpt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000008:administration & dosage* / Q000097:blood* / Q000627:therapeutic use; D015331:Cohort Studies; D016903:Drug Monitoring; D004977:Ethambutol / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D005260:Female; D006078:Government Programs; D006801:Humans; D007538:Isoniazid / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012293:Rifampin / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D016896:Treatment Outcome; D014397:Tuberculosis, Pulmonary / Q000097:blood* / Q000188:drug therapy*; D014768:Virginia / Q000453:epidemiology; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D004977:Ethambutol; D007538:Isoniazid; D012293:Rifampin