The integrase inhibitor dolutegravir is being considered in several countries in sub-Saharan Africa instead of efavirenz for people initiating antiretroviral therapy (ART) because of superior tolerability and a lower risk of resistance emergence. WHO requested updated modelling results for its 2019 Antiretroviral Guidelines update, which was restricted to the choice of dolutegravir or efavirenz in new ART initiators. In response to this request, we modelled the risks and benefits of alternative policies for initial first-line ART regimens.
We updated an existing individual-based model of HIV transmission and progression in adults to consider information on the risk of neural tube defects in women taking dolutegravir at time of conception, as well as the effects of dolutegravir on weight gain. The model accounted for drug resistance in determining viral suppression, with consequences for clinical outcomes and mother-to-child transmission. We sampled distributions of parameters to create various epidemic setting scenarios, which reflected the diversity of epidemic and programmatic situations in sub-Saharan Africa. For each setting scenario, we considered the situation in 2018 and compared ART initiation policies of an efavirenz-based regimen in women intending pregnancy, and a dolutegravir-based regimen in others, and a dolutegravir-based regimen, including in women intending pregnancy. We considered predicted outcomes over a 20-year period from 2019 to 2039, used a 3% discount rate, and a cost-effectiveness threshold of US$500 per disability-adjusted life-year (DALY) averted.
Considering updated information on risks and benefits, a policy of ART initiation with a dolutegravir-based regimen rather than an efavirenz-based regimen, including in women intending pregnancy, is predicted to bring population health benefits (10 990 DALYs averted per year) and to be cost-saving (by $2·9 million per year), leading to a reduction in the overall population burden of disease of 16 735 net DALYs per year for a country with an adult population size of 10 million. The policy involving ART initiation with a dolutegravir-based regimen in women intending pregnancy was cost-effective in 87% of our setting scenarios and this finding was robust in various sensitivity analyses, including around the potential negative effects of weight gain.
In the context of a range of modelled setting scenarios in sub-Saharan Africa, we found that a policy of ART initiation with a dolutegravir-based regimen, including in women intending pregnancy, was predicted to bring population health benefits and be cost-effective, supporting WHO\'s strong recommendation for dolutegravir as a preferred drug for ART initiators.
Bill & Melinda Gates Foundation.

The HIV type-1 nonnucleoside reverse transcriptase inhibitor, efavirenz, is widely used to treat HIV type-1 infection. Efavirenz is predominantly metabolized into inactive metabolites by cytochrome P450 (CYP)2B6, and patients with certain CYP2B6 genetic variants may be at increased risk for adverse effects, particularly central nervous system toxicity and treatment discontinuation. We summarize the evidence from the literature and provide therapeutic recommendations for efavirenz prescribing based on CYP2B6 genotypes.

Recent updates to the GOLD guidelines emphasize the use of combination LABA and LAMA bronchodilators for patients with chronic obstructive pulmonary disease with persistent dyspnea despite monotherapy or frequent exacerbations despite LAMA monotherapy. There are several commercially available LABA/LAMA fixed dose combination inhalers, which are likely to become the principle therapy for many patients with COPD.
In the last 4 years, there have been a number of large clinical trials evaluating the efficacy and safety of combined LAMA and LABA bronchodilators. LAMA/LABA fixed dose combination therapies have consistently demonstrated clinically significant improvements to airway obstruction, dyspnea, and quality of life whenever compared with placebo, and more modest improvements compared with bronchodilator monotherapies and combined bronchodilator/inhaled corticosteroid therapy.
New guidelines emphasize combination bronchodilators as a mainstay of therapy for many patients with symptomatic COPD and there are several new combination bronchodilator therapies available to patients. It is important for physicians and patients to understand the range and degree of expected clinical effects and the safety profiles of these new medications.

Preventing unintended pregnancies is important among all women, including those living with HIV. Increasing numbers of women, including HIV-positive women, choose progestin-containing subdermal implants, which are one of the most effective forms of contraception. However, drug-drug interactions between contraceptive hormones and efavirenz-based antiretroviral therapy (ART) may reduce implant effectiveness. We present four inter-related perspectives on this issue.
First, as a case study, we discuss how limited data prompted country-level guidance against the use of implants among women concomitantly using efavirenz in South Africa and its subsequent negative effects on the use of implants in general. Second, we discuss the existing clinical data on this topic, including the observational study from Kenya showing women using implants plus efavirenz-based ART had three-fold higher rates of pregnancy than women using implants plus nevirapine-based ART. However, the higher rates of pregnancy in the implant plus efavirenz group were still lower than the pregnancy rates among women using common alternative contraceptive methods, such as injectables. Third, we discuss the four pharmacokinetic studies that show 50-70% reductions in plasma progestin concentrations in women concurrently using efavirenz-based ART as compared to women not on any ART. These pharmacokinetic studies provide the biologic basis for the clinical findings. Fourth, we discuss how data on this topic have marked implications for both family planning and HIV programmes and policies globally.
This controversy underlines the importance of integrating family planning services into routine HIV care, counselling women appropriately on increased risk of pregnancy with concomitant implant and efavirenz use, and expanding contraceptive method mix for all women. As global access to ART expands, greater research is needed to explore implant effectiveness when used concomitantly with newer ART regimens. Data on how HIV-positive women and their partners choose contraceptives, as well as information from providers on how they present and counsel patients on contraceptive options are needed to help guide policy and service delivery. Lastly, greater collaboration between HIV and reproductive health experts at all levels are needed to develop successful strategies to ensure the best HIV and reproductive health outcomes for women living with HIV.

The unbound drug concentration in plasma is usually considered the only active fraction; thus the binding of a drug to a protein limits its pharmacological actions. This is of special importance for those highly bound drugs. Therefore, binding studies can be of great utility for those drugs where relationship between free and total drug concentration is variable among patients, or it can be altered by some condition or disease, or even by interactions with other drugs. However, there is a lack of validation guidelines for the determination of unbound concentrations. Antiretroviral drugs (ARVs), protease inhibitors (PIs), efavirenz and nevirapine are highly bound to proteins. Here, we present a review on the overall methods for the study of unbound fractions of highly bound plasma protein ARVs. We also provide a critical evaluation of the methods applied, their differences and the main points to be controlled and validated.

OBJECTIVE: The aim was to summarize national prevention of mother-to-child transmission (PMTCT) guidelines across Europe and to identify differences between these.
METHODS: A survey was conducted using a structured questionnaire sent to experts in 25 European countries from January to March 2012, requesting a copy of the national guidelines. Responses were received from 23 countries.
RESULTS: Twenty-two (96%) countries supported a policy to recommend antenatal HIV screening for all pregnant women (15: opt-out strategy; 8: opt-in strategy). For HIV-positive women in whom the only indication for antiretroviral therapy (ART) was PMTCT, the recommended gestational age for commencing ART varied from 12 to 28 weeks: initiation before 19 weeks gestation was recommended in guidelines from nine countries; in France, the UK and the Netherlands, there was a wide range, from 14 to 24 weeks, whereas the Swiss and Ukrainian guidelines recommended starting at 24-28 weeks and the German/Austrian and Lithuanian at 28 weeks. Six national guidelines recommended inclusion of Zidovudine in antenatal ART regimens, and seven (37%) allowed continuation of Efavirenz for women conceiving on this drug. According to nine guidelines, zidovudine should always be used intrapartum. Eighteen national guidelines stated that HIV-positive women on successful ART can have a vaginal delivery. Viral load thresholds for vaginal delivery were <1000 copies/ml in 5 countries, <400 copies/ml in 3 and <50 copies/ml in 11 countries.
CONCLUSIONS: There are important differences across Europe in national PMTCT guidelines, with most variation seen where the evidence-base remains limited. Such differences should be considered when interpreting research and surveillance findings.

OBJECTIVE: Retrospective study of all patients who started antiretroviral therapy (ART) in 2007 in a single center in Paris, with baseline characteristics and 1-year outcome, to assess adherence to national guidelines.
RESULTS: We analyzed 118 patients. Time of ART initiation was in agreement with the guidelines for only 64 (54.2%) patients. Fifty patients (42%) started ART with AIDS or a CD4 count <200 cells/mm(3). In all, 62 (52%) and 47 patients (40%) received a combination of 2 nucleoside analogues with efavirenz (EFV) and 1 ritonavir-boosted protease inhibitor (PI/r), respectively. Treatment regimens were in accordance with the guidelines for 114 patients (97%). At 1 year, 16 patients (13.5%) were lost to follow-up, only 5 (4.9%) experienced HIV disease progression or death, but 19 (18.6%) required hospitalization. Antiretroviral therapy was changed in 21 patients (21%). Ten patients (8.4%) experienced virologic failure.
CONCLUSIONS: Antiretroviral therapy was in agreement with guidelines for the choice of combination but was often initiated too late.

BACKGROUND: Therapeutic drug monitoring (TDM) is recommended in several international HIV treatment guidelines. The adherence of clinicians to these recommendations is unknown. The authors evaluated the adherence to the Dutch TDM guideline of 2005.
METHODS: From the ATHENA cohort study, three scenarios were selected for which the guideline recommended TDM: 1) start of a combination of lopinavir/ritonavir + efavirenz or nevirapine (drug-drug interaction); 2) start of efavirenz (routine TDM); and 3) use of nelfinavir during pregnancy. For each scenario, we determined the proportion of patients for whom TDM was performed. Multivariable logistic regression modeling was used to identify determinants for the use of TDM.
RESULTS: The adherence to the TDM guideline was 46.7% in patients who started lopinavir/ritonavir plus efavirenz or nevirapine; 9.5% for patients who started efavirenz; and 58.5% for patients who used nelfinavir during pregnancy. Patients treated in clinics that had a TDM assay available locally and patients treated in academic clinics were more likely to receive TDM. A higher baseline HIV viral load was another significant predictor for the performing TDM.
CONCLUSIONS: The adherence of clinicians to the Dutch TDM guidelines varied from low to moderate for the three investigated TDM scenarios. This study identifies several determinants for the use of TDM, which may be useful information for those responsible for generating TDM guidelines.

The reverse transcriptase (RT) sequences of HIV-1 subtype C isolates from Indian patients at failure (according to WHO clinical or immunological criteria) of a first-line treatment including d4T/AZT-3TC-NVP/EFV were compared to those of HIV-1 isolates from naive patients and analyzed for drug resistance mutations (DRMs), which were interpreted according to ANRS and Stanford algorithms. All viruses were of subtype C. We have observed a decrease of the polymorphism at positions 36 and 214 of RT while D121Y, V179I, and Q217E could be new DRMs. Numerous crucial DRMs to NRTIs and NNRTIs could be recorded including TAMs of pathway 1 and K65R. According to both algorithms, the accumulation of DRMs may induce resistance to second-line NRTIs including tenofovir.

BACKGROUND: Our main objectives were to study the population pharmacokinetics of efavirenz and to explore the adequacy of dosing guidelines.
METHODS: A total of 33 HIV-1-infected patients were recruited from the Emma Children\'s Hospital (Amsterdam, the Netherlands). Gender, age, drug formulation, the presence of the c.516G>T polymorphism in the CYP2B6 gene and the quantitation of liver enzymes alanine aminotransferase and aspartate aminotransferase at baseline were collected. A non-linear mixed effect pharmacokinetic model was developed.
RESULTS: CYP2B6 genotype and drug formulation significantly influenced efavirenz pharmacokinetics. Clearance was 29.7% lower in children carrying the CYP2B6-516-G/T genotype compared with children carrying the G/G genotype. Relative bioavailiability of the oral liquid compared with tablets or capsules was 46.6%. Children carrying the CYP2B6-516-G/G genotype had a 50-70% probability of developing a subtherapeutic trough level of efavirenz and only 1-3% probability of developing a trough level >4 mg/l. To reduce the probability of developing a subtherapeutic trough concentration, we propose to give an adult efavirenz dose to children weighing > or =25 kg and to allometrically scale doses for other weight levels a priori. The dose of the oral solution should be twice the dose of capsules.
CONCLUSIONS: Population pharmacokinetics of efavirenz in children were adequately described. Current dosing guidelines can result in subtherapeutic concentrations in children carrying the CYP2B6-516-G/G genotype and with the liquid formulation. A priori dose adaptations in the paediatric population seem feasible and need prospective validation.