Adherence and acceptability of once daily Lamivudine and abacavir in human immunodeficiency virus type-1 infected children

Fixed-dose antiretroviral combinations in children living with human immunodeficiency virus type 1 (HIV-1): a systematic review

Fixed-Dose antiretroviral Combinations (FDCs) are the most used drug regimes in adult patients with human-immunodeficiency virus 1 infection, since they increase adherence to antiretroviral therapy and enable good quality of life. The European AIDS Clinical Society guidelines recommend the use of FDCs in paediatrics. However, the use of FDCs in paediatric population is restricted since studies in children and adolescents are mostly conducted in small sample sizes and are heterogeneous in settings and design. This systematic review aims to summarize the current knowledge about the use of FDCs in paediatric population, highlighting the relevant outcomes regarding efficacy and effectiveness, adherence, safety, and adverse events of these regimens.

Weight-adapted fixed-dose combined adult antiretroviral tablets for HIV-infected children

WHAT IS KNOWN AND OBJECTIVE

Therapeutic alternatives to simplify antiretroviral therapy (ART) in HIV-infected children are needed. We report our experience with abacavir(ABC)/lamivudine(3TC) individualized dose compounded capsules (IDCC).

COMMENT

We present a prospective case series of HIV-infected children who did not weigh enough to receive the adult fixed-dose combination including ABC/3TC 600mg/300mg, and were treated with weight-adapted ABC/3TC IDCC in Barcelona, Spain. Thirteen patients (12 girls) received ABC/3TC IDCC for a median(IQR) time of 30(17-54) months. No significant changes were observed in CD4 cell counts, weight or height z-scores over time. Suppression of viral replication was maintained in 7 patients with undetectable viremia at baseline. Another 5 patients achieved viral suppression with ABC/3TC IDCC-based ART, while one non-adherent girl did not. No adverse events related to ABC/3TC IDCC were observed.

WHAT IS NEW AND CONCLUSION

Despite small numbers, the long-term use of ABC/3TC IDCC was feasible, safe, and effective in the treatment of HIV-infected children.

Pediatric Antiretroviral Therapy

Human immunodeficiency virus (HIV) is one of the most serious pediatric infectious diseases, affecting around 3 million children and adolescents worldwide. Lifelong antiretroviral treatment (ART) provides multiple benefits including sustained virologic suppression, restoration and preservation of immune function, decreased morbidity and mortality, and improved quality of life. However, access to ART, particularly among neonates and young infants, continues to be challenging due to limited number of suitable formulations and limited access to pediatric ARV drug. Moreover, children and adolescents living with HIV may experience long-term HIV- and ART-associated comorbidities including cardiovascular, renal, neurological, and metabolic complications. We provide an overview of currently available formulations, dosing, and safety considerations for pediatric antiretroviral drugs by drug classes and according to the three age groups including neonates, children, and adolescents.

Once vs twice-daily abacavir and lamivudine in African children

BACKGROUND

Antiretroviral therapy (ART) adherence is critical for successful HIV treatment outcomes. Once-daily dosing could improve adherence. Plasma concentrations of once-daily vs twice-daily abacavir + lamivudine are bioequivalent in children, but no randomized trial has compared virological outcomes.

METHODS

Children taking abacavir + lamivudine-containing first-line regimens twice daily for more than 36 weeks in the ARROW trial (NCT02028676, ISRCTN24791884) were randomized to continue twice-daily vs move to once-daily abacavir + lamivudine (open-label). Co-primary outcomes were viral load suppression at week 48 (12% noninferiority margin, measured retrospectively) and lamivudine or abacavir-related grade 3/4 adverse events.

RESULTS

Six hundred and sixty-nine children (median 5 years, range 1-16) were randomized to twice daily (n = 333) vs once daily (n = 336) after median 1.8 years on twice-daily abacavir + lamivudine-containing first-line ART. Children were followed for median 114 weeks. At week 48, 242/331 (73%) twice daily vs 236/330 (72%) once daily had viral load less than 80 copies/ml [difference -1.6% (95% confidence interval -8.4,+5.2%) P = 0.65]; 79% twice daily vs 78% once daily had viral load less than 400 copies/ml (P = 0.76) (week 96 results similar). One grade 3/4 adverse event was judged uncertainly related to abacavir + lamivudine (hepatitis; once daily). At week 48, 9% twice daily vs 10% once daily reported missing one or more ART pills in the last 4 weeks (P = 0.74) and 8 vs 8% at week 96 (P = 0.90). Carers strongly preferred once-daily dosing. There was no difference between randomized groups in postbaseline drug-resistance mutations or drug-susceptibility; WHO 3/4 events; ART-modifying, grade 3/4 or serious adverse events; CD4% or weight-for-age/height-for-age (all P > 0.15).

CONCLUSION

Once-daily abacavir + lamivudine was noninferior to twice daily in viral load suppression, with similar resistance, adherence, clinical, immunological and safety outcomes. Abacavir + lamivudine provides the first once-daily nucleoside backbone across childhood that can be used to simplify ART.

A model-based approach for the evaluation of once daily dosing of lamivudine in HIV-infected children

AIM

Little attention has been paid to the effects of compliance and prescription practice on treatment outcome in HIV-infected children. In this context, an evaluation of the role of covariates on pharmacokinetics is required to establish the impact of differences in dosing regimens. Here we investigate whether a once daily dosing regimen of lamivudine provides comparable exposure to the currently approved paediatric regimen.

METHODS

A hypothetical group of 180 patients between 3 months and 12 years old was used to evaluate the impact of body weight on systemic exposure to lamivudine. Simulation scenarios were evaluated using AUC and Cmax as parameters of interest. The analysis was performed using a population pharmacokinetic model previously implemented in nonmem v.6.2.

RESULTS

The simulations show that once daily dosing of lamivudine yields comparable exposure to historical values observed in children and adults, both for liquid and solid dosage forms. Simulated steady-state AUC(0-24 h) and Cmax values after once daily doses ranged respectively from 9.9  mg l⁻¹  h and 1.9 mg l⁻¹ for children lighter than 14 kg to 13.75 mg l⁻¹  h and 3.0 mg l⁻¹ for children heavier than 30 kg. These values are comparable or higher than historical values observed after once daily dosing in children and adults.

CONCLUSIONS

Our findings illustrate how dosing regimens can be evaluated taking into account the effects of developmental growth on drug disposition. Most importantly, they suggest that the reduction in dosing frequency to once daily leads to comparable lamivudine exposure, as observed after administration of a twice daily dosing regimen.

Paediatric European Network for Treatment of AIDS (PENTA) guidelines for treatment of paediatric HIV-1 infection 2015: optimizing health in preparation for adult life

The 2015 Paediatric European Network for Treatment of AIDS (PENTA) guidelines provide practical recommendations on the management of HIV‐1 infection in children in Europe and are an update to those published in 2009. Aims of treatment have progressed significantly over the last decade, moving far beyond limitation of short‐term morbidity and mortality to optimizing health status for adult life and minimizing the impact of chronic HIV infection on immune system development and health in general. Additionally, there is a greater need for increased awareness and minimization of long‐term drug toxicity. The main updates to the previous guidelines include: an increase in the number of indications for antiretroviral therapy (ART) at all ages (higher CD4 thresholds for consideration of ART initiation and additional clinical indications), revised guidance on first‐ and second‐line ART recommendations, including more recently available drug classes, expanded guidance on management of coinfections (including tuberculosis, hepatitis B and hepatitis C) and additional emphasis on the needs of adolescents as they approach transition to adult services. There is a new section on the current ART ‘pipeline’ of drug development, a comprehensive summary table of currently recommended ART with dosing recommendations. Differences between PENTA and current US and World Health Organization guidelines are highlighted and explained.

Pharmacokinetics of atazanavir/ritonavir among HIV-infected Thai children concomitantly taking tenofovir disoproxil fumarate

BACKGROUND

Atazanavir/ritonavir (ATV/r) is a recommended once-daily protease inhibitor. Tenofovir disoproxil fumarate (TDF) can reduce ATV exposure. The authors studied ATV pharmacokinetic (PK) parameters among children who received atazanavir/ritonavir co-administered with TDF.

METHODS

HIV-infected children aged 6-18 years with a body weight of 25-50 kg were eligible. Branded ATV 200 mg/capsule was taken with generic ritonavir 100 mg/tablet once daily plus TDF and lamivudine. A 24-hour PK study was performed at week 4 at t = 0 (pre-dose), 2, 4, 6, 8, 10, 12 and 24 hours. PK parameters were calculated using non-compartmental methods with WinNonlin software. Targeted ATV AUC 0-24 was 15 mg h/L and C trough was 0.15 mg/L. Comparisons of geometric means of ATV PK parameters between different weight bands were made using regression models.

RESULTS

Eighteen HIV-infected children with a median (IQR) age of 13 (11-14) years were enrolled. Median (range) body weight and body surface area were 35 (25-42) kg and 1.21 (0.96-1.35) m2, respectively. Median (IQR) CD4 cell count was 735 (540-1233) cells/mm3. Median (range) of ATV was 164 (145-209) mg/m2. Geometric mean (SD) ATV AUC 0-24 was 35.05 (1.06) mg h/L, and ATV C trough was 0.31 (1.13) mg/L. No child had ATV AUC 0-24 or C trough below target levels. There were no significant differences in PK parameters among weight bands.

CONCLUSION

Atazanavir/ritonavir 200/100 mg dosing provided adequate ATV AUC 0-24 when used with TDF in HIV-infected Thai children weighing between 25 and 50 kg.

Once-daily antiretroviral therapy in a cohort of HIV-infected children and adolescents

We evaluated the evolution over time of once-daily antiretroviral therapy in HIV-infected children and its relationship with adherence. An increase on the prevalence of once-daily antiretroviral therapy was observed over time (from 0.9% in 2002 to 44.2% in 2011). There was no difference in adherence regarding once-daily or BID regimens in 2011. Adherence was related to age and pill burden.

Etravirine in treatment-experienced, HIV-1-infected children and adolescents: 48-week safety, efficacy and resistance analysis of the phase II PIANO study

OBJECTIVES

PIANO (Paediatric study of Intelence As an NNRTI Option; TMC125-C213; NCT00665847) assessed the safety/tolerability, antiviral activity and pharmacokinetics of etravirine plus an optimized background regimen (OBR) in treatment-experienced, HIV-1-infected children (≥ 6 to < 12 years) and adolescents (≥ 12 to < 18 years) over 48 weeks.

METHODS

In a phase II, open-label, single-arm study, 101 treatment-experienced patients (41 children; 60 adolescents) with screening viral load (VL) ≥ 500 HIV-1 RNA copies/mL received etravirine 5.2 mg/kg (maximum dose 200 mg) twice a day (bid) plus OBR.

RESULTS

Sixty-seven per cent of patients had previously used efavirenz or nevirapine. At week 48, the most common treatment-related grade ≥ 2 adverse event (AE) was rash (13%); 12% experienced grade 3 AEs. Only two grade 4 AEs occurred (both thrombocytopaenia, not etravirine related). At week 48, 56% of patients (68% children; 48% adolescents) achieved a virological response (VL<50 copies/mL; intent-to-treat, noncompleter=failure). Factors predictive of response were adherence > 95%, male sex, low baseline etravirine weighted genotypic score and high etravirine trough concentration (C0h ). Seventy-six patients (75%) completed the trial; most discontinuations occurred because of protocol noncompliance or AEs (8% each). Sixty-five per cent of patients were > 95% adherent by questionnaire and 39% by pill count. Forty-one patients experienced virological failure (VF; time-to-loss-of-virological-response non-VF-censored algorithm) (29 nonresponders; 12 rebounders). Of 30 patients with VF with paired baseline/endpoint genotypes, 18 (60%) developed nonnucleoside reverse transcriptase inhibitor (NNRTI) mutations, most commonly Y181C. Mean etravirine area under the plasma concentration-time curve over 12 h (AUC0-12h ; 5216 ng h/mL) and C0h (346 ng/mL) were comparable to adult target values.

CONCLUSIONS

Results with etravirine 5.2 mg/kg bid (with OBR) in this treatment-experienced paediatric population and etravirine 200 mg bid in treatment-experienced adults were comparable. Etravirine is an NNRTI option for treatment-experienced paediatric patients.

Adherence to antiretroviral therapy in children attending Mulago Hospital, Kampala

BACKGROUND

Non-adherence reduces the effectiveness of antiretroviral therapy in children attending the paediatric HIV/AIDS clinic at Mulago Hospital, Kampala.

AIM

To determine the levels of adherence to HAART and identify factors associated with non-adherence.

METHODS

A cross-sectional study of 170 children aged 2-18 years. Adherence to HAART was defined as taking > or =95% of prescribed medication. It was determined using three measures: a 3-day self-report by the caregivers, clinic-based pill counts at enrolment and home-based unannounced pill counts 2-3 weeks later.

RESULTS

The 3-day self-reported > or =95% adherence was 89.4% (n=170). Using clinic-based pill counts, 94.1% (n=170) had > or =95% adherence to treatment compared with only 72% (n=164) by unannounced pill counts. When the primary caregiver was the only one who knew the child's serostatus, he/she was three times more likely to be non-adherent (p=0.02, OR 3.34, 95% CI 1.14-9.82). Those who had been hospitalised twice or more before starting HAART were more likely to have > or =95% adherence (p=0.02, OR 0.44, 95% CI 0.20-0.92).

CONCLUSION

The majority of children had good adherence levels when estimated by unannounced pill counts. Disclosing the child's HIV serostatus only to the primary caregiver and having been hospitalised only once or not at all were associated with poor adherence.

A meta-analysis of adherence to antiretroviral therapy and virologic responses in HIV-infected children, adolescents, and young adults

The relationship between adherence to antiretroviral therapy (ART) and virologic outcomes in HIV+ children, adolescents, and young adults has been notably understudied, with much of the extant research focused on specific sub-literatures, such as resource-limited regions, specific clinical outcomes and time frames. The authors sought to better characterize the relationship between adherence to ART and virologic functioning along various sample and methodological factors. The authors conducted a meta-analysis of thirty-seven studies and utilized a random effects model to generate weighted mean effect sizes. In addition, the authors conducted meta-ANOVAs to examine potential factors influencing the relationship between adherence and three categories of clinical outcomes, specifically Viral Load (VL) <100, VL < 400, and continuously measured VL. The analyses included 5,344 HIV+ children, adolescents, and young adults. The relationship between adherence behaviors and virologic outcomes varied across different methods of measurement and analysis. The relationship between adherence and continuously measured VL was significantly larger than for dichotomously-coded VL < 400 at Qb (20.69(1), p < .0005). Caregiver self-report indices elicited very small to small magnitude effects across both VL < 100 and VL < 400 outcomes and combined informant reporting (youth/adolescent and parent) produced significantly larger effects than caregiver report alone with adherence and VL < 400 outcomes at Qb (9.28(1), p < .005). More recently published trials reported smaller relationships between adherence and categorical clinical outcomes, such that year of publication significantly negatively correlated with VL < 100 (r = -.71(14), p < .005) and VL < 400 (r = -.43(26), p < .02). The data suggest that the magnitude of the relationship between ART adherence and virologic outcomes among heterogeneous samples of HIV+ children, adolescents and young adults varies across virologic outcomes and may be affected by moderating sample and methodological factors. Methodological and research recommendations for the interpretation of the current findings as well as for future HIV adherence related research are presented.

Adherence to antiretroviral therapy and acceptability of planned treatment interruptions in HIV-infected children

There have been no paediatric randomised trials describing the effect of planned treatment interruptions (PTIs) of antiretroviral therapy (ART) on adherence, or evaluating acceptability of such a strategy. In PENTA 11, HIV-infected children were randomised to CD4-guided PTIs (n = 53) or continuous therapy (CT, n = 56). Carers, and children if appropriate, completed questionnaires on adherence to ART and acceptability of PTIs. There was no difference in reported adherence on ART between CT and PTI groups; non-adherence (reporting missed doses over the last 3 days or marking <100 % adherence since the last clinical visit on a visual analogue scale) was 18 % (20/111) and 14 % (12/83) on carer questionnaires in the CT and PTI groups respectively (odds ratios, OR (95 % CI) = 1.04 (0.20, 5.41), χ² (1) = 0.003, p = 0.96). Carers in Europe/USA reported non-adherence more often (31/121, 26 %) than in Thailand (1/73, 1 %; OR (95 % CI) = 54.65 (3.68, 810.55), χ² (1) = 8.45, p = 0.004). The majority of families indicated they were happy to have further PTIs (carer: 23/36, 64 %; children: 8/13, 62 %), however many reported more clinic visits during PTI were a problem (carer: 15/36, 42 %; children: 6/12, 50 %).

How can we simplify antiretroviral therapy in children?

PURPOSE OF REVIEW

The aim of this article is to present approaches towards simplifying pediatric antiretroviral therapy in order to improve access to care, coverage of HIV-positive children, and support adherence to treatment.

RECENT FINDINGS

Barriers to rapid and effective global scale-up of pediatric antiretroviral therapy include the narrow range of available pediatric antiretrovirals, complicated dosing schedules, and social and economic instability of the family caused by poverty, stigma, and death. Healthcare providers can simplify antiretroviral therapy delivery by promoting the development and use of pediatric fixed dose combinations and scored adult antiretrovirals, using weight-band dosing tables to prescribe antiretrovirals, and identifying less complex regimens. Caretakers would benefit from active counseling to facilitate more open communication with their children about adherence and disclosure. Children can develop long-term coping strategies through learning life skills that build confidence and improve decision-making. Whenever possible, antiretroviral therapy programs should provide access to free antiretrovirals, identify funds to cover transportation costs, and refer families to available community support programs.

SUMMARY

Interventions to simplify the administration of antiretroviral therapy need to address not only how antiretrovirals are prescribed and formulated, but the relationships of HIV-positive children with their families and communities as well.

Antiretroviral drugs in pediatric HIV-infected patients: pharmacokinetic and practical challenges

Antiretroviral (ARV) therapy has been shown to achieve high therapeutic efficacy in treating pediatric HIV disease. The delivery of affordable, child friendly, and easy to store and administer ARV drugs is key to the successful management of HIV in children. In recent years, significant progress has been made in scaling up the access to pediatric ARV therapy among children worldwide. Despite the improved ARV drug access, multiple challenges remain concerning palatability and efficient delivery of ARV drugs to children from infancy into adolescence. Data are limited regarding developmental changes in pharmacokinetics of individual ARV drugs, and pediatric and adult fixed-dose combinations. This review provides a practical discussion regarding the pharmacokinetics of ARV agents in pediatric HIV-infected patients, as well as the practical challenges of currently available formulations, such as palatability of liquid formulations, challenges of crushing tablets, and using adult and pediatric fixed-dose combinations.

Pharmacokinetics and acceptability of once- versus twice-daily lamivudine and abacavir in HIV type-1-infected Ugandan children in the ARROW Trial

BACKGROUND

No data on once-daily dosing of nucleoside analogues in African children currently exist. We compared the pharmacokinetics (PK) of once- versus twice-daily lamivudine and abacavir treatment using the World Health Organization recommended weight band dosing of scored adult tablets.

METHODS

HIV type-1 (HIV-1)-infected Ugandan children aged 3-12 years receiving antiretroviral therapy that included lamivudine and abacavir twice daily (total 150+300 mg, 225+450 mg and 225/300+600 mg daily for 12-<20, 20-<25 and ≥25 kg, respectively) were enrolled in a crossover study. Plasma PK sampling (at 0, 1, 2, 4, 6, 8 and 12 h after observed morning intake) was performed for the twice-daily regimen at steady-state. Children were then switched to once-daily treatment with PK sampling repeated 4 weeks later (with an additional 24 h sample). Acceptability questionnaires were completed at both time points. Daily area under the curve (AUC(0-24)) and maximum concentrations (C(max)) were compared by geometric mean ratios (GMRs).

RESULTS

A total of 41 HIV-1-infected children (median age of 7 years) and n=23, n=14 and n=4 in 12-<20, 20-<25 and ≥25 kg weight bands, respectively, were enrolled. Mean AUC(0-24) was 13.0 and 12.0 mg•h/l for once- and twice-daily lamivudine (GMR 1.09, 90% confidence intervals [CI] 0.98-1.20) and 15.3 and 15.6 mg•h/l for once- and twice-daily abacavir (GMR 0.98, 90% CI 0.89-1.08), respectively, with no difference in 3-6 versus 7-12 year olds. C(max) was 76% (lamivudine) and 64% (abacavir) higher on once-daily regimens. For both children and caregivers, once-daily dosing of lamivudine plus abacavir was highly acceptable and strongly preferred over twice-daily.

CONCLUSIONS

In children aged 3-12 years, AUC(0-24) of lamivudine and abacavir were bioequivalent on once- and twice-daily regimens. Once-daily dosing of abacavir and lamivudine could provide an alternative dosing strategy for HIV-1-infected children, with high acceptability and strong preference suggesting the potential for improved adherence.

PENTA 2009 guidelines for the use of antiretroviral therapy in paediatric HIV-1 infection

PENTA Guidelines aim to provide practical recommendations for treating children with HIV infection in Europe. Changes to guidance since 2004 have been informed by new evidence and by expectations of better outcomes following the ongoing success of antiretroviral therapy (ART). Participation in PENTA trials of simplifying treatment is encouraged. The main changes are in the following sections: 'When to start ART': Treatment is recommended for all infants, and at higher CD4 cell counts and percentages in older children, in line with changes to adult guidelines. The number of age bands has been reduced to simplify and harmonize with other paediatric guidelines. Greater emphasis is placed on CD4 cell count in children over 5 years, and guidance is provided where CD4% and CD4 criteria differ. 'What to start with': A three-drug regimen of two nucleoside reverse transcriptase inhibitors (NRTIs) with either a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (PI) remains the first choice combination. Lamivudine and abacavir are the NRTI backbone of choice for most children, based on long-term follow-up in the PENTA 5 trial. Stavudine is no longer recommended. Whether to start with an NNRTI or PI remains unclear, but PENPACT 1 trial results in 2009 may help to inform this. All PIs should be ritonavir boosted. Recommendations on use of resistance testing, therapeutic drug monitoring and HLA testing draw from data in adults and from European paediatric cohort studies. Recently updated US and WHO paediatric guidelines provide more detailed review of the evidence base. Differences between guidelines are highlighted and explained.

Novel strategies in the use of lopinavir/ritonavir for the treatment of HIV infection in children

Lopinavir/ritonavir (LPV/r) is considered by many as the first choice protease inhibitor (PI) for children. This co-formulation avoids the need for children to take ritonavir separately to “boost” the levels of lopinavir. LPV/r has high virologic potency, an excellent toxicity profile and a high barrier to the development of viral resistance. However, LPV/r has poor tolerability of the oral suspension (due to the poor taste of ritonavir), difficult dosing requirements and metabolic side effects, especially hyperlipidemia. The new tablet low-dose formulation (100/25 mg) may allow more convenient antiretroviral treatment in children. Novel strategies of LPV/r in childhood could maximize its advantages. For example, infants infected with HIV despite single dose Nevirapine after birth need effective combination antiretroviral treatment. This can be given using a higher dose of LPV/r with therapeutic drug monitoring. Other novel uses include once daily LPV/r regimens in older children and adolescents and lower doses of LPV/r in certain populations, which may decrease hyperlipidemia. Heavily pre-treated children might benefit from a double PI/r regimen which includes LPV/r. The high potency of LPV/r needs to be balanced with convenient regimens, to enhance adherence and decrease toxicity whenever possible. The aim of this review is to discuss the rationale behind these novel strategies of LPV/r use in pediatric antiretroviral treatment as well as their results and limitations.

Pharmacokinetic study of once-daily versus twice-daily abacavir and lamivudine in HIV type-1-infected children aged 3-<36 months

BACKGROUND

Once-daily dosing of abacavir and lamivudine has been approved for adults, but paediatric data are insufficient. We conducted a pharmacokinetic study of once-daily and twice-daily abacavir and lamivudine in children aged 3-<36 months.

METHODS

Children with stable HIV type-1 (HIV-1) RNA levels after 12 weeks treatment with twice-daily abacavir (8 mg/kg) with or without lamivudine (4 mg/kg) underwent plasma pharmacokinetic sampling. Children then switched to once-daily abacavir (16 mg/kg) with or without lamivudine (8 mg/kg), and sampling was repeated 4 weeks later. The area under the plasma concentration-time curve over 24 h (AUC(0-24)) and the maximum concentration (C(max)) were compared using geometric mean ratios (GMRs); 90% confidence intervals (CIs) within the range of 0.80-1.25 were considered bioequivalent.

RESULTS

A total of 18 children (4, 6 and 8 in the 3-<12, 12-<24 and 24-<36 month age ranges, respectively) provided pharmacokinetic data for abacavir (17 for lamivudine). The GMR of AUC(0-24), once-daily versus twice-daily, was 1.07 (90% CI 0.92-1.23) for abacavir and 0.91 (90% CI 0.79-1.06) for lamivudine. C(max) almost doubled on once-daily versus twice-daily dosing: abacavir and lamivudine GMRs were 2.04 (90% CI 1.73-2.42) and 1.78 (90% CI 1.52-2.09), respectively. At baseline, 12, 24 and 48 weeks, 89%, 94%, 100% and 89% of children had HIV-1 RNA<400 copies/ml, respectively.

CONCLUSIONS

Bioequivalence was demonstrated on AUC(0-24) between twice-daily and once-daily abacavir; very similar AUC(0-24) values were seen for twice-daily and once-daily lamivudine. Given that viral load suppression rates were maintained, these data suggest that once-daily abacavir and lamivudine might be an option for children aged 3-<36 months.

A feasibility study of immediate versus deferred antiretroviral therapy in children with HIV infection

OBJECTIVE

To evaluate the feasibility of a large immediate versus deferred antiretroviral therapy (ART) study in children.

METHODS

We conducted an open-label pilot randomized clinical trial study in 43 Thai children with CD4 15 to 24% of starting generic AZT/3TC/NVP immediately (Arm 1) or deferring until CD4 < 15% or CDC C (Arm 2). Primary endpoints were recruitment rate, adherence to randomized treatment and retention in trial. Secondary endpoints were % with CDC C or CD4 < 15%. Children were in the trial until the last child reached 108 weeks. Intention to treat and on treatment analyses were performed.

RESULTS

Recruitment took 15 months. Twenty-six of 69 (37.7%) were not eligible due mainly to low CD4%. Twenty four and 19 were randomized to arms 1 and 2 respectively. All accepted the randomized arm; however, 3 in arm 1 stopped ART and 1 in arm 2 refused to start ART. Ten/19 (53%) in arm 2 started ART. At baseline, median age was 4.8 yrs, CDC A:B were 36:7, median CD4 was 19% and viral load was 4.8 log. All in arm 1 and 17/19 in arm 2 completed the study (median of 134 weeks). No one had AIDS or death. Four in immediate arm had tuberculosis. Once started on ART, deferred arm children achieved similar CD4 and viral load response as the immediate arm. Adverse events were similar between arms. The deferred arm had a 26% ART saving.

CONCLUSION

Almost 40% of children were not eligible due mainly to low CD4% but adherence to randomized treatment and retention in trial were excellent. A larger study to evaluate when to start ART is feasible.

A systematic review of pediatric adherence to antiretroviral therapy in low- and middle-income countries

BACKGROUND

Sustaining antiretroviral therapy (ART) adherence requires accurate, consistent monitoring, a particular challenge for low-income countries. The optimal strategy to measure pediatric adherence remains unclear.

OBJECTIVE

To conduct a systematic review of pediatric ART adherence measurement techniques, adherence estimates, and clinical correlates in low- and middle-income countries to inform ART adherence monitoring.

METHODS

We searched online bibliographic databases, including MEDLINE and EMBASE, using systematic criteria. Two reviewers selected all descriptive or interventional studies involving nonpregnant, HIV-positive individuals < or =18 years old that measured ART adherence in low- or middle-income countries as defined by World Bank criteria. Data were extracted regarding sample characteristics, study setting, measurement strategy, adherence estimate, and adherence correlates.

RESULTS

The search yielded 1566 titles, of which 17 met selection criteria. Adherence measurement strategies included self- or proxy-report measures (14 studies), pill counts (4 studies), pharmacy records, drug levels, clinic adherence, and directly observed therapy (1 study each). The self- or proxy-report measures were heterogeneous, and few employed validation strategies. Caregiver-reported adherence was generally higher than self-report estimates. Pill counts revealed lower adherence estimates. Estimates of ART adherence ranged from 49% to 100%, with 76% of articles reporting >75% adherence. Factors related to family structure, socioeconomic status, disclosure, and medication regimen were all significantly associated with ART adherence.

CONCLUSIONS

Pediatric HIV care programs in low- and middle-income countries use heterogeneous methods to measure ART adherence. Adherence estimates vary substantially, but most studies from low- and middle-income countries report >75% adherence, whereas most studies from high-income countries report <75% adherence.

Treatment of children with HIV infection

The treatment of pediatric HIV infection has seen vast improvements in terms of better long-term suppression of HIV replication and subsequent improvements in the longevity and quality of life in children. This has been realized, in part, by development of newer antiretroviral medications, better knowledge about the pharmaco-kinetics of these drugs in children, and improved insight on drug toxicities in children. This review will discuss some of the newer agents that may be available for children in the near future, in addition to new pharmacokinetic and toxicity data that are specific to the pediatric patient. New information on key vaccines that should be administered to children with HIV infection is also discussed.