Pharmacokinetics of indinavir combined with low-dose ritonavir in human immunodeficiency virus type 1-infected children

Cell-type specific expression of the vasopressin gene analyzed by AAV mediated gene delivery of promoter deletion constructs into the rat SON in vivo

The magnocellular neurons (MCNs) in the supraoptic nucleus (SON) of the hypothalamus selectively express either oxytocin (Oxt) or vasopressin (Avp) neuropeptide genes. In this paper we examine the cis-regulatory domains in the Avp gene promoter that are responsible for its cell-type specific expression. AAV vectors that contain various Avp gene promoter deletion constructs using EGFP as the reporter were stereotaxically injected into the rat SON. Two weeks following the injection immunohistochemical assays of EGFP expression from these constructs were done to determine whether the expressed EGFP reporter co-localizes with either the Oxt- or Avp-immunoreactivity in the MCNs. The results identify three major enhancer domains located at −2.0 to −1.5 kbp, −1.5 to −950 bp, and −950 to −543 bp in the Avp gene promoter that regulate the expression in Avp MCNs. The results also show that cell–type specific expression in Avp MCNs is maintained in constructs containing at least 288 bp of the promoter region upstream of the transcription start site, but this specificity is lost at 116 bp and below. Based on these data, we hypothesize that the −288 bp to −116 bp domain contains an Avp MCN specific activator and a possible repressor that inhibits expression in Oxt-MCNs, thereby leading to the cell-type specific expression of the Avp gene only in the Avp-MCNs.

Indinavir/low-dose ritonavir containing HAART in HIV-1 infected children has potent antiretroviral activity, but is associated with side effects and frequent discontinuation of treatment

We here present the study results of 21 HIV-1 infected children who were treated with indinavir plus low-dose ritonavir and two nucleoside reverse transcriptase inhibitors (NRTIs) for 48 weeks. Although this q12h HAART regimen had potent antiretroviral activity, it was frequently associated with side effects and discontinuation of therapy.

Indinavir/ritonavir remains an important component of HAART for the treatment of HIV/AIDS, particularly in resource-limited settings

For over a decade, indinavir has been approved for the treatment of HIV/AIDS; however, following the introduction of new protease inhibitors (PIs) with improved safety and pharmacologic profiles, its use in developed countries has become almost obsolete. In contrast, in resource-limited settings where the majority of people living with HIV/AIDS reside, indinavir is part of the most affordable PI-based highly active antiretroviral treatment regimen. A major drawback of indinavir use is renal toxicity, but low-dose indinavir plus ritonavir (400/100 mg) twice daily is both efficacious and tolerable. Similar low dosing levels in children have also proven successful, but data in pregnant women remains limited. Due to its low cost and proven efficacy indinavir remains a key component of HIV/AIDS treatment in resource-limited settings.

Age-dependent pharmacokinetics of lamivudine in HIV-infected children

The recommended dose of lamivudine in children is higher when compared with adults: 4 mg/kg vs approximately 2 mg/kg (150 mg) and administered twice a day. Limited data are available to demonstrate that this increased dose results in adequate exposure to lamivudine in children with human immunodeficiency virus (HIV) infection. Data were selected from children who were using lamivudine for at least 2 weeks before a full pharmacokinetic (PK) study was conducted. Lamivudine PK parameters were significantly related to age. The age of 6 years appeared to be a cutoff for a change in PK parameters of lamivudine, with children <6 years of age (n=17) having a median area under the curve 43% lower and a median peak plasma concentration 47% lower (both P<0.001) than older children (n=34). In conclusion, further investigation of the relationship between decreased lamivudine exposure and treatment outcome and long-term resistance development in younger children with HIV infection is warranted.

Efficacy and plasma concentrations of indinavir when boosted with ritonavir in human immunodeficiency virus-infected Thai children

We evaluated 19 children using 220-300 mg/m of indinavir (IDV) boosted with 100 mg ritonavir (RTV) (n = 12) or full-dose RTV (n = 7). Geometric mean (GM) (90% confidence interval, CI) of IDV Ctrough in children who took IDV with 100 mg RTV (n = 12) was 0.17 (0.06-0.50) mg/L. For children who took IDV with full-dosage RTV, GM (90% CI) was 0.40 (0.10-1.61) mg/L. C2hours were less than 10 mg/L in all subjects. Eighteen children had good virologic response. This report demonstrates that smaller IDV dosages given with RTV provide efficacious plasma concentrations and can be safely used.

Hepatotoxicity and antiretroviral therapy with protease inhibitors: A review

Highly active antiretroviral therapy including protease inhibitors has led to dramatic decrease in the morbidity and mortality resulting from infection with human immunodeficiency virus-1. However, this combination regimen can be associated with the occurrence of serious toxicities, which may reduce patient compliance. In particular, human immunodeficiency virus-1 protease inhibitors and nevirapine among nonnucleoside reverse transcriptase inhibitors, have the potential for producing hepatotoxicity. We summarise current knowledge of the hepatotoxic effects associated with the commercially available human immunodeficiency virus-1 protease inhibitors based on a literature review of the major retrospective and prospective clinical studies designed to elucidate risk factors for developing hepatotoxicity among human immunodeficiency virus-1-infected patients receiving antiretroviral therapy containing protease inhibitors. Coinfection with chronic hepatitis, a common occurrence in human immunodeficiency virus-1-infected patients, is identified as an independent risk factor for developing hepatotoxicity in antiretroviral-treated human immunodeficiency virus-1-infected patients treated with antiretroviral regimens containing protease inhibitors. The importance of other risk factors for developing protease inhibitor-associated hepatotoxicity and the mechanism underlying the drug-related hepatotoxicity are discussed. The data indicate that the potential for producing hepatotoxicity is variable among the protease inhibitors and suggest that based on differences in drug-related hepatotoxicity, certain protease inhibitors may be preferred for the treatment of human immunodeficiency virus-hepatitis C virus coinfected patients.