Background: Surgical placement of a gastrostomy tube (g-tube) directly into a patient's gastrointestinal system to support antiretroviral administration is occasionally used to increase adherence in HIV-infected children. Absorption and distribution characteristics of antiretrovirals after g-tube administration, however, are unknown. The goal of this pilot study was to describe the pharmacokinetic characteristics of protease inhibitors (PIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) when administered to HIV-infected children via g-tube.
Method: Nine HIV-infected children who were receiving a PI- or NNRTI-containing regimen via g-tube were enrolled. All antiretrovirals (excluding efavirenz) were administered under direct observation for the pharmacokinetic evaluation. Blood samples were collected at predose and at 1, 2, 4, 8, and 12 hours postdose. Antiretroviral concentrations were measured in plasma using high performance liquid chromatography with ultraviolet detection.
Results: Systemic exposure of PIs and NNRTIs in our 9 patients was similar to data from historical oral administration controls. Due to likely drug interactions, LPV exposure was decreased and one patient had low exposure of all antiretrovirals. When doses were increased, adequate exposure was attained.
Conclusion: This pilot study suggests that administration of most PIs and NNRTIs by a g-tube to HIV-infected children provides systemic exposure comparable with that achieved after oral administration.