Pharmacokinetics and Safety of a Raltegravir-Containing Regimen in Children Aged 4 Weeks to 2 Years Living With Human Immunodeficiency Virus and Receiving Rifampin for Tuberculosis.

Pharmacological interactions limit treatment options for children living with human immunodeficiency virus (HIV) and tuberculosis (TB). We found that 12 mg/kg twice daily raltegravir chewable tablets (administered after crushing) safely achieved pharmacokinetic targets in children living with HIV aged 4 weeks to <2 years receiving concurrent rifampin to treat TB. CLINICAL TRIALS REGISTRATION: NCT01751568.

Pharmacokinetics and safety of a raltegravir-containing regimen in HIV-infected children aged 2-12 years on rifampicin for tuberculosis.

OBJECTIVES: Drug-drug interactions limit current antiretroviral treatment options for HIV-infected children with tuberculosis (TB). Rifampicin (RIF) induces UDP-glucuronosyltransferase activity, accelerating the clearance of raltegravir (RAL). We sought to establish an optimal and well tolerated dose of RAL when administered with RIF to HIV and TB co-infected children. DESIGN: P1101 is a phase I/II open-label dose-finding study of RAL with RIF for children 2 to less than 12 years of age beginning treatment for HIV and active TB. SETTING: Four sites in South Africa. METHODS: Chewable RAL was given at 12 mg/kg per dose twice daily (twice the usual pediatric dose) with two nucleoside reverse transcriptase inhibitors. Intensive RAL pharmacokinetic sampling was conducted 5 to 8 days after antiretroviral therapy was initiated; a fourth antiretroviral agent was then added. RESULTS: Children were recruited into two age-defined groups: cohort 1 (2 to <6 years old) and cohort 2 (6 to <12 years old). Pharmacological targets [geometric mean (GM) AUC12 h of 14-45 µmol/l h and GM C12 h ≥75 nmol/l) were reached in both cohort 1 (28.8 µmol/l h and 229 nmol/l) and cohort 2 (38.8 µmol/l h and 228 nmol/l). The RAL-based ART was well tolerated by most participants: one participant discontinued treatment because of grade 4 hepatitis that was possibly treatment-related. At week 8, 22 of 24 participants (92%) had HIV RNA concentrations below 400 copies/ml; 19 of 24 (79%) were below 50 copies/ml. CONCLUSION: Giving 12 mg/kg twice daily of the chewable RAL formulation achieved pharmacokinetic targets safely in HIV-infected children receiving RIF for TB.