Thai national guidelines for antiretroviral therapy in HIV-1 infected adults and adolescents 2010

In Thailand, more than 150,000 patients are currently treated with antiretroviral drugs under the support of the National AIDS Program (NAP). The appointed Adults and Adolescents Committee consisted of 28 members who are experts in HIV research, patient care or health care policy. Relevant published literature, guidelines, and the most recent relevant clinical trials presented internationally were reviewed. Several peer review and clinical studies conducted in Thailand were included in the review process. Special considerations for patients with co-infection of tuberculosis or hepatitis B were incorporated. Appropriate cut-off of CD4+ T-cell counts when to commence ART among Thai patients have been considered. It is now recommended to start ART at CD4+ T-cell count <350 cells/mm3. For treatment-naive patients, the preferred initial therapy is a nonnucleoside reverse transcriptase inhibitor (NNRTI)-based regimen containing lamivudine plus zidovudine or tenofovir. Stavudine will be phased out in a two-year plan at the national program level. Viral load and CD4+ T-cell counts should be monitored at least once and twice a year. To achieve long-term treatment success, enhancing adherence together with the proper management of antiretroviral-related toxicity is critical. In summary, the major changes from the Thai 2008 guidelines include commencing ART earlier. ART is recommended regardless of CD4+ T cell count if patients have an indication to treat their HBV co-infection. Preferred first regimen uses AZT or TDF, not d4T as the NRTI-backbone. Furthermore, efavirenz is now considered a preferred NNRTI, along with nevirapine.

Addressing Antiretroviral Therapy-Associated Drug-Drug Interactions in Patients Requiring Treatment for Opportunistic Infections in Low-Income and Resource-Limited Settings

An increasing number of human immunodeficiency virus (HIV)-infected patients are achieving virologic suppression on antiretroviral therapy (ART) limiting the use of primary and secondary antimicrobial prophylaxis. However, in low-income and resource-limited settings, half of those infected with HIV are unaware of their diagnosis, and fewer than 50% of patients on ART achieve virologic suppression. Management of comorbidities and opportunistic infections among patients on ART may lead to inevitable drug-drug interactions (DDIs) and even toxicities. Elderly patients, individuals with multiple comorbidities, those receiving complex ART, and patients living in low-income settings experience higher rates of DDIs. Management of these cytochrome P450-mediated, nonmediated, and drug transport system DDIs is critical in HIV-infected patients, particularly those in resource-limited settings with few options for ART. This article critically analyzes and provides recommendations to manage significant DDIs and drug toxicities in HIV-infected patients receiving ART.

K. HK, Ramachandran G, Shet A. Sub-therapeutic nevirapine concentration during antiretroviral treatment initiation among children living with HIV: Implications for therapeutic drug monitoring

Nevirapine, a component of antiretroviral therapy (ART) in resource-limited settings, known for auto-induction of metabolism, is initiated at half therapeutic dose until day 14 (‘lead-in period’), and subsequently escalated to full dose. However, studies have shown that this dosing strategy based on adult studies may not be appropriate in children, given that younger children have higher drug clearance rates. In this prospective cohort study, we studied trough plasma nevirapine levels by high performance liquid chromatography (HPLC) at days 7, 14 (lead-in period) and 28 (full dose period) after ART initiation amongst HIV-1 infected children initiating nevirapine-based ART in southern India. Among the 20 children (50% male, median age 9 years) included in the study, sub-therapeutic trough plasma nevirapine concentration (<4μg/ml) was seen in 65% (13/20) of children during the lead-in period within two weeks of ART initiation and among 10% of children at 4 weeks during full-dose nevirapine. Adherence was documented as ≥95% in all children by both caregiver self-report and pill count. Median nevirapine concentrations achieved at week 1 was 4.8 μg/ml, significantly lower than 8 μg/ml, the concentration achieved at week 4 (p = 0.034). Virological failure at one year of ART was observed in six children, and was not associated with median nevirapine concentration achieved during week 1, 2 or 4. We conclude that the dose escalation strategy currently practiced among young children living with HIV-1 resulted in significant subtherapeutic nevirapine concentration (≤4μg/ml) during the lead-in period. We call for a closer look at pediatric-focused dosing strategies for nevirapine initiation in young children. Further studies to establish age-appropriate threshold nevirapine concentration are warranted in young children to corroborate the role of therapeutic drug monitoring in predicting virological outcome.

The pharmacological challenges of treating tuberculosis and HIV coinfections

INTRODUCTION

Tuberculosis (TB) is the most prevalent opportunistic infection among HIV patients, and the leading cause of death among HIV patients worldwide. Simultaneous treatment of both diseases is recommended by current guidelines, but can be challenging due to the potential for drug-drug interactions, overlapping toxicities, difficulty adhering to medications, and an increased risk for immune reconstitution inflammatory syndrome (IRIS). Clinical manifestations of TB can also vary between HIV-infected patients and uninfected patients, which can increase the risk for delayed diagnosis. Areas covered: Topics covered in this review include the following: the inter-related pathophysiology of HIV and TB; clinical manifestations and diagnosis; drug-drug interactions, particularly the rifamycins with the antiretrovirals; IRIS presentation and treatment, as well as a discussion on overlapping toxicity between the two disease states. Expert commentary: The complexity of managing these two disease states simultaneously requires a multidisciplinary approach to care and dedicated resources. If properly funded, TB/HIV co-infection will continue to decline over the coming years.

Official American Thoracic Society/Centers for Disease Control and Prevention/Infectious Diseases Society of America Clinical Practice Guidelines: Treatment of Drug-Susceptible Tuberculosis

The American Thoracic Society, Centers for Disease Control and Prevention, and Infectious Diseases Society of America jointly sponsored the development of this guideline for the treatment of drug-susceptible tuberculosis, which is also endorsed by the European Respiratory Society and the US National Tuberculosis Controllers Association. Representatives from the American Academy of Pediatrics, the Canadian Thoracic Society, the International Union Against Tuberculosis and Lung Disease, and the World Health Organization also participated in the development of the guideline. This guideline provides recommendations on the clinical and public health management of tuberculosis in children and adults in settings in which mycobacterial cultures, molecular and phenotypic drug susceptibility tests, and radiographic studies, among other diagnostic tools, are available on a routine basis. For all recommendations, literature reviews were performed, followed by discussion by an expert committee according to the Grading of Recommendations, Assessment, Development and Evaluation methodology. Given the public health implications of prompt diagnosis and effective management of tuberculosis, empiric multidrug treatment is initiated in almost all situations in which active tuberculosis is suspected. Additional characteristics such as presence of comorbidities, severity of disease, and response to treatment influence management decisions. Specific recommendations on the use of case management strategies (including directly observed therapy), regimen and dosing selection in adults and children (daily vs intermittent), treatment of tuberculosis in the presence of HIV infection (duration of tuberculosis treatment and timing of initiation of antiretroviral therapy), as well as treatment of extrapulmonary disease (central nervous system, pericardial among other sites) are provided. The development of more potent and better-tolerated drug regimens, optimization of drug exposure for the component drugs, optimal management of tuberculosis in special populations, identification of accurate biomarkers of treatment effect, and the assessment of new strategies for implementing regimens in the field remain key priority areas for research. See the full-text online version of the document for detailed discussion of the management of tuberculosis and recommendations for practice.

Low-dose versus standard-dose ritonavir-boosted atazanavir in virologically suppressed Thai adults with HIV (LASA): a randomised, open-label, non-inferiority trial

BACKGROUND

Thai patients with HIV have higher exposure to HIV protease inhibitors than do white people and dose reduction might be possible. We compared the efficacy of low-dose with standard-dose ritonavir-boosted atazanavir in virologically suppressed Thai patients with HIV.

METHODS

In this randomised, open-label, non-inferiority trial, we recruited patients aged 18 years or older who were receiving ritonavir-boosted protease-inhibitor-based antiretroviral therapy (ART) with HIV plasma viral loads of less than 50 copies per mL, an alanine aminotransferase concentration of less than 200 IU/L, and a creatinine clearance of at least 60 mL/min from 14 hospitals in Thailand. We excluded patients who had active AIDS-defining disease or opportunistic infections, had a history of an HIV viral load of 1000 copies per mL or more after 24 weeks of any ritonavir-boosted protease-inhibitor-based ART, used concomitant medications that could interact with the study drugs, were pregnant or lactating, had illnesses that might change the effect of the study drugs, or had a history of sensitivity to the study drugs. A biostatistician at the study coordinating centre randomly allocated patients (1:1) to switch the protease inhibitor for oral atazanavir 200 mg and ritonavir 100 mg or for atazanavir 300 mg and ritonavir 100 mg once daily, both with two nucleoside or nucleotide reverse transcriptase inhibitors at recommended doses. Randomisation was done with a minimisation schedule, stratified by recruiting centre, use of tenofovir, and use of indinavir as a component of the preswitch regimen. The primary endpoint was the proportion of patients with viral loads of less than 200 copies per mL at week 48, and we followed up patients every 12 weeks. Treatments were open label, the non-inferiority margin was -10%, and all patients who received at least one dose of study medication were analysed. This trial is registered with ClinicalTrials.gov, number NCT01159223.

FINDINGS

Between July 6, 2011, and Dec 23, 2013, we randomly assigned 559 patients: 279 to receive atazanavir 200 mg and ritonavir 100 mg (low dose) and 280 to atazanavir 300 mg and ritonavir 100 mg (standard dose). At week 48, 265 (97·1%) of 273 in the low-dose group and 267 (96·4%) of 277 in the standard-dose group had viral loads of less than 200 copies per mL (difference 0·68; 95% CI -2·29 to 3·65). Seven (3%) of 273 in the low-dose group and 21 (8%) of 277 in the standard-dose group discontinued their assigned treatment (p=0·01). 46 (17%) of 273 participants in the low-dose group and 97 (35%) of 277 in the standard-dose group had total bilirubin grade 3 or higher toxicity (≥3·12 mg/dL; p<0·0001).

INTERPRETATION

A switch to low-dose atazanavir should be recommended for Thai patients with well controlled HIV viraemia while on regimens based on boosted protease inhibitors.

FUNDING

The National Health Security Office and Kirby Institute for Infection and Immunity in Society.

Integrated therapy for HIV and tuberculosis

Tuberculosis (TB) has been the most common opportunistic infection and cause of mortality among HIV-infected patients, especially in resource-limited countries. Clinical manifestations of TB vary and depend on the degree of immunodeficiency. Sputum microscopy and culture with drug-susceptibility testing are recommended as a standard method for diagnosing active TB. TB-related mortality in HIV-infected patients is high especially during the first few months of treatment. Integrated therapy of both HIV and TB is feasible and efficient to control the diseases and yield better survival. Randomized clinical trials have shown that early initiation of antiretroviral therapy (ART) improves survival of HIV-infected patients with TB. A delay in initiating ART is common among patients referred from TB to HIV separate clinics and this delay may be associated with increased mortality risk. Integration of care for both HIV and TB using a single facility and a single healthcare provider to deliver care for both diseases is a successful model. For TB treatment, HIV-infected patients should receive at least the same regimens and duration of TB treatment as HIV-uninfected patients. Currently, a 2-month initial intensive phase of isoniazid, rifampin, pyrazinamide, and ethambutol, followed by 4 months of continuation phase of isoniazid and rifampin is considered as the standard treatment of drug-susceptible TB. ART should be initiated in all HIV-infected patients with TB, irrespective of CD4 cell count. The optimal timing to initiate ART is within the first 8 weeks of starting antituberculous treatment and within the first 2 weeks for patients who have CD4 cell counts <50 cells/mm(3). Non-nucleoside reverse transcriptase inhibitor (NNRTI)-based ART remains a first-line regimen for HIV-infected patients with TB in resource-limited settings. Although a standard dose of both efavirenz and nevirapine can be used, efavirenz is preferred because of more favorable treatment outcomes. In the settings where raltegravir is accessible, doubling the dose to 800 mg twice daily is recommended. Adverse reactions to either antituberculous or antiretroviral drugs, as well as immune reconstitution inflammatory syndrome, are common in patients receiving integrated therapy. Early recognition and appropriate management of these consequences can reinforce the successful integrated therapy in HIV-infected patients with TB.

Guidelines for antiretroviral therapy in HIV-1 infected adults and adolescents 2014, Thailand

New evidence has emerged regarding when to commence antiretroviral therapy (ART), optimal treatment regimens, management of HIV co-infection with opportunistic infections, and management of ART failure. The 2014 guidelines were developed by the collaborations of the Department of Disease Control, Ministry of Public Health (MOPH) and the Thai AIDS Society (TAS). One of the major changes in the guidelines included recommending to initiating ART irrespective of CD4 cell count. However, it is with an emphasis that commencing HAART at CD4 cell count above 500 cell/mm³ is for public health, in term of preventing HIV transmission and personal benefit. In tuberculosis co-infected patients with CD4 cell counts ≤50 cells/mm³ or with CD4 cell counts >50 cells/mm³ who have severe clinical disease, ART should be initiated within 2 weeks of starting tuberculosis treatment. The preferred initial ART regimen in treatment naïve patients is efavirenz combined with tenofovir and emtricitabine or lamivudine. Plasma HIV viral load assessment should be done twice a year until achieving undetectable results; and will then be monitored once a year. CD4 cell count should be monitored every 6 months until CD4 cell count ≥350 cells/mm³ and with plasma HIV viral load <50 copies/mL; then it should be monitored once a year afterward. HIV drug resistance genotypic test is indicated when plasma HIV viral load >1,000 copies/mL while on ART. Ritonavir-boosted lopinavir or atazanavir in combination with optimized two nucleoside-analogue reverse transcriptase inhibitors is recommended after initial ART regimen failure. Long-term ART-related safety monitoring has also been included in the guidelines.

Nevirapine or efavirenz for tuberculosis and HIV coinfected patients: exposure and virological failure relationship

Objectives

We describe nevirapine and efavirenz exposure on and off tuberculosis treatment and consequences for virological efficacy and tolerance in patients included in the ANRS 12146/12214-CARINEMO trial.

Methods

Participants were randomly selected to receive either nevirapine at 200 mg twice daily (n = 256) or efavirenz at 600 mg daily (n = 270), both combined with two nucleoside analogues. Blood samples were drawn 12 h after nevirapine or efavirenz administration, while on tuberculosis treatment and after tuberculosis treatment discontinuation. In 62 participants, samples taken 12 h after drug administration were drawn weekly for the first month of ART. Sixteen participants participated in an extensive pharmacokinetic study of nevirapine. Concentrations were compared with the therapeutic ranges of 3000–8000 ng/mL for nevirapine and 1000–4000 ng/mL for efavirenz.

Results

Nevirapine concentrations at the end of the first week of treatment (on antituberculosis drugs) did not differ from concentrations off tuberculosis treatment, but declined thereafter. Concentrations at steady-state were 4111 ng/mL at week 12 versus 6095 ng/mL at week 48 (P < 0.0001). Nevirapine concentrations <3000 ng/mL were found to be a risk factor for virological failure. Efavirenz concentrations were higher on than off tuberculosis treatment (2700 versus 2450 ng/mL, P < 0.0001).

Conclusions

The omission of the 2 week lead-in dose of nevirapine prevented low concentrations at treatment initiation but did not prevent the risk of virological failure. Results support the WHO recommendation to use efavirenz at 600 mg daily in patients on rifampicin-based antituberculosis therapy.