Nancy R. Calles

Pharmacologic Characteristics of Indinavir, Didanosine, and Stavudine in Human Immunodeficiency Virus-Infected Children Receiving Combination Therapy

ABSTRACT The use of human immunodeficiency virus (HIV) protease inhibitors in children has lagged behind that in adults because of the lack of suitable pediatric formulations and information on safe and effective dosing regimens. This study was designed to obtain pharmacokinetic information on indinavir, administered to HIV-infected children also receiving therapy with two nucleoside agents, and to explore relationships between pharmacokinetic parameters and anti-HIV effect. Indinavir was initiated at a dose of 500 mg/m2 every 8 h. Plasma indinavir concentrations were measured every 4 weeks; the dose or dosing interval was adjusted to maintain trough concentrations of ≥0.1 mg/liter. All children were evaluated clinically at baseline and every 4 weeks. Plasma HIV RNA was quantitated at baseline and at weeks 4, 12, and 24. Eighteen children participated in this study. The average daily dose of indinavir was 2,043 mg/m2; nine children received indinavir at 6-h intervals. Pharmacokinetic characteristics of indinavir (mean ± standard deviation) were the following: oral clearance, 1.4 ± 0.5 liters/h/kg; half-life, 1.1 ± 0.43 h; and trough concentration, 0.29 ± 0.32 mg/liter. In nine children that completed 24 weeks of therapy, the baseline-to-week-24 change in HIV RNA level was related to indinavir trough concentration and didanosine area under the curve. This study illustrates the ability to obtain pharmacokinetic information from children during routine clinic visits and to use this information to provide a safeguard against underdosing. The incorporation of pharmacologic knowledge with virologic, immunologic, and behavioral considerations should result in improved clinical outcomes for children infected with HIV.

The pediatric pulmonary and cardiovascular complications of vertically transmitted human immunodeficiency virus (P2C2 HIV) infection study: Design and methods

The P2C2 HIV Study is a prospective natural history study initiated by the National Heart, Lung, and Blood Institute in order to describe the types and incidence of cardiovascular and pulmonary disorders that occur in children with vertically transmitted HIV infection (i.e., transmitted from mother to child in utero or perinatally). This article describes the study design and methods. Patients were recruited from five clinical centers in the United States. The cohort is composed of 205 infants and children enrolled after 28 days of age (Group I) and 612 fetuses and infants of HIV-infected mothers, enrolled prenatally (73%) or postnatally at age < 28 days (Group II). The maternal-to-infant transmission rate in Group II was 17%. The HIV-negative infants in Group II (Group IIb) serves as a control group for the HIV-infected children (Group IIa). The cohort is followed at specified intervals for clinical examination, cardiac, pulmonary, immunologic, and infectious studies and for intercurrent illnesses. In Group IIa, the cumulative loss-to-follow-up rate at 3 years was 10.5%, and the 3-year cumulative mortality rate was 24.9%. The findings will be relevant to clinical and epidemiologic aspects of HIV infection in children.

A pilot study of combination therapy with indinavir, stavudine (d4t), and didanosine (ddi) in children infected with the human immunodeficiency virus

Twelve children infected with the human immunodeficiency virus were treated orally with indinavir, stavudine, plus didanosine for 12 to 48 weeks. Therapy was limited in some cases by nonadherence, intolerance, toxicity, and virologic failure. Marked increases in CD4+ lymphocyte counts and decreases in plasma human immunodeficiency virus RNA concentrations suggest that the regimen has potent antiviral activity.

Pharmacokinetics and pharmacodynamics of saquinavir in pediatric patients with human immunodeficiency virus infection

Our objective was to investigate the clinical pharmacologic characteristics of saquinavir given as a soft gelatin capsule, either alone or in combination with nelfinavir, to children and adolescents with human immunodeficiency virus infection.

Comprehensive pediatric human immunodeficiency virus care and treatment in Constanta, romania: Implementation of a program of Highly active antiretroviral therapy in a resource-poor setting

Background: Relatively few human immunodeficiency virus (HIV)-infected children worldwide have access to care and treatment. The Romanian-American Children’s Center, a collaborative project of a U.S. health care institution and the Romanian government, has established a comprehensive program of highly active antiretroviral therapy for children in Constanta, Romania. Objectives: To describe the design and outcomes of a program of pediatric HIV/acquired immunodeficiency syndrome (AIDS) care and treatment in a resource-poor setting. Setting: Outpatient center providing comprehensive primary and HIV/AIDS specialty care and treatment to all known HIV-infected children living in Constanta County, Romania. Outcomes: As of August 2003, a total of 452 children were receiving highly active antiretroviral therapy. Therapy has been well-tolerated, with ~90% of children continuing to receive treatment after a median duration of follow-up of 67 weeks. Normal weight and height growth velocities have been observed among treated children. Marked decreases have been observed in rates of hospitalization and mortality. The mean change in CD4+ lymphocyte count for 173 children who have both a baseline count and at least 1 follow-up count is +284 cells/μL (P < 0.0001). Conclusions: Highly active antiretroviral therapy can be administered safely and effectively to children in a resource-poor setting, with outcomes comparable with those observed in U.S. pediatric antiretroviral clinical trials.

Long-term Follow-up of 414 HIV-Infected Romanian Children and Adolescents Receiving Lopinavir/Ritonavir-Containing Highly Active Antiretroviral Therapy

BACKGROUND. There are no published reports of the long-term safety and effectiveness of highly active antiretroviral therapy for children and adolescents living in resource-limited settings or of large cohorts of HIV-infected children and adolescents treated long-term (>48 weeks) with lopinavir/ritonavir-containing highly active antiretroviral therapy. OBJECTIVES. The purpose of this work was to evaluate the long-term outcomes of treatment of HIV-infected children and adolescents with lopinavir/ritonavir-containing highly active antiretroviral therapy in a resource-limited setting. METHODS. We studied an inception cohort of 414 HIV-infected children receiving lopinavir/ritonavir-containing highly active antiretroviral therapy between November 2001 and August 2006 at the Romanian-American Childrens Center in Constanta, Romania. The center provides comprehensive primary and HIV specialty care and treatment to all known HIV-infected children and adolescents living in Constanta. We measured safety and effectiveness by the percentage of children remaining on treatment, rates of mortality, and changes in plasma HIV RNA concentrations and CD4+ lymphocyte counts. RESULTS. The study population consisted predominantly of antiretroviral drug–experienced older children and adolescents with advanced HIV disease. Treatment was well tolerated, with 337 children (81%) remaining on therapy after a median duration of >4 years. Thirty-seven deaths occurred; the death rate compared favorably to prospectively collected historical data. The most recent on-treatment plasma HIV RNA concentration was <400 copies per milliliter in 192 of 265 children tested. The mean baseline CD4+ lymphocyte count was 292 cells per microliter (n = 299); the mean change from baseline was +266 (n = 284), +317 (n = 260), +343 (n = 176), and +270 cells per microliter (n = 121) after 1, 2, 3, and 4 years of treatment, respectively. CONCLUSIONS. Highly active antiretroviral therapy can be administered safely and effectively to children and adolescents in resource-limited settings. Lopinavir/ritonavir-containing highly active antiretroviral therapy is a safe, effective, and durable treatment option for antiretroviral drug–experienced older children and adolescents with advanced HIV disease.

Combination therapy with saquinavir soft gelatin capsules in children with human immunodeficiency virus infection

OBJECTIVES To evaluate the pharmacokinetics, tolerance, safety and antiviral activity of the HIV protease inhibitor, saquinavir, formulated as soft gelatin capsules (SQV-SGC), given in combination with nucleoside antiretroviral agents (NRTIs) with or without nelfinavir in HIV-infected children. METHODS This was an open label study of HIV-infected children ages 3 to 16 years, conducted in two parts. In Part 1 of the study 14 children were treated orally with SQV-SGC (initially given in three 33-mg/kg doses daily; dosage adjusted to 50 mg/kg three times daily based on initial pharmacokinetics) and two NRTIs. Addition of nelfinavir was permitted for children who did not achieve a predetermined steady state target plasma saquinavir exposure. In Part 2 a new group of 13 children received SQV-SGC (33 mg/kg three times daily) in combination with nelfinavir and one or two NRTIs. Pharmacokinetics were assessed after the first dose and 4 weeks into treatment (steady state). Patients were treated for 72 and 48 weeks in Parts 1 and 2, respectively. RESULTS Most adverse events were mild; the most commonly reported were diarrhea, abdominal discomfort and headache. Two children were withdrawn from the study because of adverse events (one each of nausea and dysphagia) related to the study treatment. There were no deaths or serious adverse events attributed to the study medication. Steady state saquinavir area under the plasma concentration vs. time curves (AUC24) were 6,210 and 11,010 ng/h/ml for Parts 1 and 2, respectively. Compared with baseline measurements median changes in plasma HIV RNA concentrations were -2.12 log10 copies/ml [5 of 14 (36%) with HIV RNA <50 copies/ml) (Week 72)] and -2.58 log10 copies/ml [8 of 13 (62%) <50 copies/ml) (Week 48)] in Parts 1 and 2, respectively. The median changes in CD4+ lymphocyte count were +292 and +154 cells/microl for Parts 1 and 2, respectively. Genotypic resistance assays revealed a low frequency of saquinavir-associated resistance mutations after 48 weeks of therapy, with only 2 of 27 children having substitutions at positions 48V and/or 90M. CONCLUSIONS Combination therapy with SQV-SGC was well-tolerated and safe in HIV-infected children, and antiviral activity was observed. Saquinavir plasma concentrations were lower than expected, particularly for Part 1 (SQV-SGC plus NRTIs), but addition of nelfinavir increased saquinavir exposures.

The Pediatric AIDS Corps: responding to the African HIV/AIDS health professional resource crisis.

Health professional capacity for delivery of HIV/AIDS care and treatment is severely constrained across sub-Saharan Africa. African health professional expertise in pediatrics is in particularly short supply. Here we describe a Pediatric AIDS Corps program that was designed to place pediatricians and other physicians in Africa on a long-term basis to expand existing health professional capacity for pediatric and family HIV/AIDS care and treatment. In the first 2 years of this program, 76 physicians were placed in 5 African countries that have been hit hard by HIV/AIDS. Enrollment of HIV-infected children in care more than quadrupled over a 24-month period, to 26 590. We believe that this pilot program can serve as a model for larger-scale efforts to immediately expand access for African children and families to life-saving HIV/AIDS care and treatment.

HIV and Childhood Disability: A Case-Controlled Study at a Paediatric Antiretroviral Therapy Centre in Lilongwe, Malawi

Background As paediatric antiretroviral therapy (ART) is rapidly scaled up in Southern Africa, Human Immunodeficiency Virus (HIV) infection is becoming a chronic illness. Children growing up with HIV may begin to encounter disabilities. The relationship between HIV, disability and the need for rehabilitation has added an additional element that needs to be addressed by paediatric HIV treatment programmes. Study Objectives 1) Estimate the prevalence of disabilities in HIV-infected and HIV-uninfected children in Lilongwe, Malawi. 2) Examine types of disability and associated clinical and socio-demographic factors. 3) Identify needs, opportunities and barriers for rehabilitation in Malawi. Methods A case-controlled study of 296 HIV-infected children aged 2–9 years attending an ART centre in Lilongwe (cases) and their uninfected siblings (controls) was conducted. Disability was assessed using the WHO Ten Question Screen (TQS). Socio-demographic and clinical data were collected using a parent-proxy questionnaire and medical records. Results Of 296 case and control pairs recruited, 33% (98) versus 7% (20) screened positive for a disability (OR 8.4, 4.4–15.7) respectively. Of these 98 HIV-infected cases, 6%, 36%, 33%, 53%, 46% and 6% had a vision, hearing; physical, learning/comprehension, speech or seizure-related disability respectively and 51% had multiple coexisting disabilities. HIV-infected cases with a disability were more likely to be WHO stage III or IV at enrolment (71% vs. 52%, OR 2.7, 1.5–4.2), to have had TB (58% vs. 39%, OR 2.3, 1.4–3.8) and to have below-average school grades (18% vs. 2%, OR 11.1, 2.2–54.6) than those without. Sixty-seven percent of cases with a disability had never attended any rehabilitative service. Twenty-nine percent of caregivers reported facing stigma and discrimination because of the child’s disability. Conclusion This study reveals the magnitude of disability among HIV-infected children and the large unmet need for rehabilitation services. This expanding issue demands further investigation to provide an evidence base for holistic care for disabled children living with HIV.

Education and preparation of physicians entering an international pediatric AIDS program: the Pediatric AIDS Corps.

The Pediatric AIDS Corps (PAC) are a group of physicians that were hired to provide clinical care and treatment to children and their families infected with HIV/AIDS and to help educate local health care professionals in the management of children with HIV/AIDS located in the high prevalence areas of sub-Saharan Africa. Prior to their departure the PAC were required to participate in a 4-week educational training program that included travel and tropical medicine and HIV infections in children, teaching skills, bioethics, and good clinical practice in human research training. Evaluation of the program was done using a 50-question pretest/posttest design, a standard postcourse evaluation, and a PAC focus group follow-up. Fifty-two physicians were hired who had been trained in the following specialties: pediatrics (77%), medicine/pediatrics (9%), family medicine (8%), and internal medicine (6%). Posttest scores improved by a mean of 10 points for all PAC physicians (p < 0.001) but those that had been in Africa for 5 months or more prior to the course continued to score higher than the other participants. Reviewing the results by category demonstrated significant improvement in all areas (p < or = 0.002) except for general pediatrics for the HIV/AIDS infected patients (p = 0.124) and psychosocial issues (p = 0.376). Changes for the next training were implemented based upon the information obtained from the PAC focus group. The foundation provided by this educational course was an important beginning for the PAC physicians. Other groups providing specialized care to patients in developing countries might consider a similar educational program.