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

Description and consequences of prescribing off-label antiretrovirals in the Madrid Cohort of HIV-infected children over a quarter of a century (1988-2012)

BACKGROUND

Licensing data for paediatric dosing is often sparse and subsequent studies may result in changes to recommended doses. We measured the extent and consequences of off-label antiretroviral (ARV) use in an HIV-infected paediatric cohort.

METHODS

In this multicentre cohort study involving 318 HIV-infected children and adolescents from the Madrid Cohort, all off-label prescriptions from March 1988 to March 2012 were recorded from the clinical records. The reasons for prescribing ARV off-label, the side effects and the consequences of incorrect dosing of ARVs are discussed.

RESULTS

Among the 318 patients of the cohort, 221 (69%) received off-label ARVs according to EMA licensing at the time of prescription, representing 23% (540) of the 2,353 prescribed ARVs. The main reason for starting an off-label drug was treatment failure. Adverse events led to treatment discontinuation in 12% of the prescriptions. Problems taking the drug led to withdrawal in 5%, more likely when formulation was not suitable for age (P<0.05). Up to 10% were overdosed and 10% underdosed, defined as 25% above or below the current recommended dose, respectively. Treatment failure occurred significantly more frequently among underdosed compared to overdosed patients (50% versus 26%; P<0.05).

CONCLUSIONS

Off-label use of ARVs was common in our HIV-1 paediatric patients. Adverse events were common but rarely led to withdrawal. Suitable formulation is important in younger children. Pharmacokinetic studies are needed as frequent incorrect dosing may occur when prescribing off-label and underdosing may lead to treatment failure.

Country of birth does not influence long-term clinical, virologic, and immunological outcome of HIV-infected children living in the Netherlands: a cohort study comparing children born in the Netherlands with children born in Sub-Saharan Africa

BACKGROUND

Immigrant HIV-infected adults in industrialized countries show a poorer clinical and virologic outcome compared with native patients. We aimed to investigate potential differences in clinical, immunological, and virologic outcome in Dutch HIV-infected children born in the Netherlands (NL) versus born in Sub-Saharan Africa (SSA) in a national cohort analysis.

METHODS

We included all HIV-infected children registered between 1996 and 2013. Descriptive statistics, mixed-effects models, and Cox proportional hazard models were used to investigate differences between groups.

RESULTS

In total, 319 HIV-infected children were registered. The majority of these children were born in SSA (n = 148, 47%) or NL (n = 113, 36%) and most were black (n = 158, 61%). Children born in NL were diagnosed at a median age of 1.2 years and initiated combination antiretroviral therapy (cART) at a median age of 2.6 years, compared with 3.7 and 5.3 years, respectively, for children born in SSA (HIV diagnosis: P < 0.001; cART initiation: P < 0.001). Despite a lower initial CD4 T-cell Z-score in children born in SSA, their immunological reconstitution was similar to children from NL. Virologic suppression was achieved in the majority of all cART-treated children (NL: 96%, SSA: 94%). There was no difference in the occurrence or timing of virologic failure.

CONCLUSIONS

Most immigrant HIV-infected children living in NL were born in SSA. Children born in SSA were diagnosed and initiated cART at an older age than children born in NL. Despite initial differences in CD4 T-cell counts and HIV viral load, the long-term immunological and virologic response to cART was similar in both groups.

Long-term response to combination antiretroviral therapy in HIV-infected children in the Netherlands registered from 1996 to 2012

OBJECTIVES

To describe demographic and treatment characteristics of the Dutch vertically HIV-infected paediatric population from 1996 to 2012, and to investigate the long-term virological and immunological response to combination antiretroviral therapy (cART), with emphasis on the influence of age at cART initiation and initial CD4 cell counts.

DESIGN

Descriptive cohort study.

METHODS

From 1996 to 2012, all paediatric HIV clinics in the Netherlands provided data on their HIV-infected population. Descriptive statistics, parametric and non-parametric comparative tests, and random-effects linear regression models were performed to investigate the different aspects of this cohort.

RESULTS

A total of 229 vertically HIV-infected children were included. The majority of all mothers (64%) and almost half of the children (43%) originated from sub-Saharan Africa. Ritonavir-boosted lopinavir and efavirenz have replaced indinavir, nelfinavir and nevirapine as preferred first-line cART regimens. Long-term CD4 T-cell reconstitution (with CD4 cell counts corrected for age) was independent of age and CD4 cell count at cART initiation. The decline in HIV viral load after cART introduction occurred faster over the studied time period. The percentage of children with an undetectable viral load rose substantially from 1996 to 2012. Mortality was 0.3 per 100 person-years.

CONCLUSION

A sustained immunological response in the Dutch paediatric HIV-infected population was independent of age as well as CD4 cell count at cART initiation, despite a higher initial HIV viral load in the youngest children. The percentage of children with an undetectable HIV viral load rose substantially over the years and there was a low mortality rate in comparison with reports from other industrialized countries.

Pharmacotherapy in pregnancy; effect of ABC and SLC transporters on drug transport across the placenta and fetal drug exposure

Pharmacotherapy during pregnancy is often inevitable for medical treatment of the mother, the fetus or both. The knowledge of drug transport across placenta is, therefore, an important topic to bear in mind when deciding treatment in pregnant women. Several drug transporters of the ABC and SLC families have been discovered in the placenta, such as P-glycoprotein, breast cancer resistance protein, or organic anion/cation transporters. It is thus evident that the passage of drugs across the placenta can no longer be predicted simply on the basis of their physical-chemical properties. Functional expression of placental drug transporters in the trophoblast and the possibility of drug-drug interactions must be considered to optimize pharmacotherapy during pregnancy. In this review we summarize current knowledge on the expression and function of ABC and SLC transporters in the trophoblast. Furthermore, we put this data into context with medical conditions that require maternal and/or fetal treatment during pregnancy, such as gestational diabetes, HIV infection, fetal arrhythmias and epilepsy. Proper understanding of the role of placental transporters should be of great interest not only to clinicians but also to pharmaceutical industry for future drug design and development to control the degree of fetal exposure.

[Evidence-based therapeutic drug monitoring for indinavir]

The HIV protease inhibitor indinavir presents a wide inter-individual variability related to an intense hepatic metabolism. Published studies were analyzed to establish whether there is evidence that therapeutic drug monitoring of indinavir could improve patient care. It was reported that indinavir virological efficacy in HIV-infected patients with wild-type virus was significantly associated with trough concentrations > 100-150 ng/mL. Concerning the exposure-toxicity relationship, the risk of occurrence of nephrotoxicity was more frequently associated with trough concentrations > 500-1 000 ng/mL. Studies with concentration-controlled indinavir therapy suggest that therapeutic drug monitoring allows to achieve safe and effective concentrations, therefore, the level of evidence of the interest of indinavir therapeutic drug monitoring is highly recommended when indinavir is not associated with ritonavir and recommended when ritonavir is combined with ritonavir.

Boosted protease inhibitors as a therapeutic option in the treatment of HIV-infected children

OBJECTIVE

Paediatric HIV treatment must address various special considerations. Administration of pharmacokinetically enhanced protease inhibitors (PIs) can improve paediatric therapeutic outcomes. The objective of this study was to review the use of boosted PI regimens in children.

METHODS

Systematic literature searches of published manuscripts and conference databases using generic drug names and specific keywords were performed to ensure thorough and balanced reporting of available data.

RESULTS

Boosted PI regimens offer multiple options across a range of ages and are efficacious in naïve and experienced children; safety and tolerability are similar to those observed in adults. Novel boosted PI simplification approaches may foster adherence and diminish resistance.

CONCLUSIONS

Boosted PIs are key components of first- and second-line treatments in children. Identifying factors associated with the response to highly active antiretroviral therapy in children may ultimately permit individualized therapies.