Evolution of Anti- Retroviral Therapy: Multiple Pills to Fixed Drug Combinations.

INTRODUCTION: First anti-retroviral drug available for the treatment of HIV/AIDS patients was Zidovudine (AZT) in 1986.1 AZT monotherapy was the only available ART and it resulted in early resistance to AZT.2 Hence there was a need for new antiretroviral drugs to treat HIV/AIDS. With a rapid development in research many new drugs came in the market. At present more than 25 antiretroviral drugs are available for the treatment of HIV/AIDS. With advancement in research and availability of RCTs results, it is evident that triple drug therapies are the only option for the treatment of HIV/AIDS to avoid early resistance. With the availability of newer and better drugs, older drugs like zalcitabine, delaverdine, stavudine were discarded. Older protease inhibitors (PIs) like indinavir, saquinavir are also being used less frequently due to availability of better PIs.

Risk of triple-class virological failure in children with HIV: a retrospective cohort study.

BACKGROUND: In adults with HIV treated with antiretroviral drug regimens from within the three original drug classes (nucleoside or nucleotide reverse transcriptase inhibitors [NRTIs], non-NRTIs [NNRTIs], and protease inhibitors), virological failure occurs slowly, suggesting that long-term virological suppression can be achieved in most people, even in areas where access is restricted to drugs from these classes. It is unclear whether this is the case for children, the group who will need to maintain viral suppression for longest. We aimed to determine the rate and predictors of triple-class virological failure to the three original drugs classes in children. METHODS: In the Collaboration of Observational HIV Epidemiological Research Europe, the rate of triple-class virological failure was studied in children infected perinatally with HIV who were aged less than 16 years, starting antiretroviral therapy (ART) with three or more drugs, between 1998 and 2008. We used Kaplan-Meier and Cox regression methods to investigate the risk and predictors of triple-class virological failure after ART initiation. FINDINGS: Of 1007 children followed up for a median of 4·2 (IQR 2·4-6·5) years, 237 (24%) were triple-class exposed and 105 (10%) had triple-class virological failure, of whom 29 never had a viral-load measurement less than 500 copies per mL. Incidence of triple-class virological failure after ART initiation increased with time, and risk by 5 years after ART initiation was 12·0% (95% CI 9·4-14·6). In multivariate analysis, older age at ART initiation was associated with increased risk of failure (p=0·02). Of 686 children starting ART with NRTIs and either a NNRTI or ritonavir-boosted protease inhibitor, the rate of failure was higher than in adults with heterosexually transmitted HIV (hazard ratio 2·2 [95% CI 1·6-3·0, p<0·0001]). INTERPRETATION: Findings highlight the challenges of attaining long-term viral suppression in children who will be taking life-long ART. Early identification of children not responding to ART, adherence support, particularly for children and adolescents aged 13 years or older starting ART, and ART simplification strategies are all needed to attain and sustain virological suppression. FUNDING: UK Medical Research Council award G0700832.

Class of antiretroviral drugs and the risk of myocardial infarction.

BACKGROUND: We have previously demonstrated an association between combination antiretroviral therapy and the risk of myocardial infarction. It is not clear whether this association differs according to the class of antiretroviral drugs. We conducted a study to investigate the association of cumulative exposure to protease inhibitors and nonnucleoside reverse-transcriptase inhibitors with the risk of myocardial infarction. METHODS: We analyzed data collected through February 2005 from our prospective observational study of 23,437 patients infected with the human immunodeficiency virus. The incidence rates of myocardial infarction during the follow-up period were calculated, and the associations between myocardial infarction and exposure to protease inhibitors or nonnucleoside reverse-transcriptase inhibitors were determined. RESULTS: Three hundred forty-five patients had a myocardial infarction during 94,469 person-years of observation. The incidence of myocardial infarction increased from 1.53 per 1000 person-years in those not exposed to protease inhibitors to 6.01 per 1000 person-years in those exposed to protease inhibitors for more than 6 years. After adjustment for exposure to the other drug class and established cardiovascular risk factors (excluding lipid levels), the relative rate of myocardial infarction per year of protease-inhibitor exposure was 1.16 (95% confidence interval [CI], 1.10 to 1.23), whereas the relative rate per year of exposure to nonnucleoside reverse-transcriptase inhibitors was 1.05 (95% CI, 0.98 to 1.13). Adjustment for serum lipid levels further reduced the effect of exposure to each drug class to 1.10 (95% CI, 1.04 to 1.18) and 1.00 (95% CI, 0.93 to 1.09), respectively. CONCLUSIONS: Increased exposure to protease inhibitors is associated with an increased risk of myocardial infarction, which is partly explained by dyslipidemia. We found no evidence of such an association for nonnucleoside reverse-transcriptase inhibitors; however, the number of person-years of observation for exposure to this class of drug was less than that for exposure to protease inhibitors.

Endogenous Hormones and Antiretroviral Exposure in Plasma, Cervicovaginal Fluid, and Upper-Layer Packed Cells of Malawian Women Living with HIV.

Overlap in metabolism pathways of endogenous female sex hormones and antiretroviral drugs may lead to altered exposure to these compounds. In a family planning clinic in Lilongwe, Malawi, blood, blood cell, and cervicovaginal fluid (CVF) samples from seventy-three HIV positive Malawian women taken in follicular and luteal menstrual phases were assessed for estradiol and progesterone by chemiluminescent immunoassay, and for antiretroviral concentration by liquid chromatography-mass spectrometry. In both follicular and luteal phases, estradiol concentrations were lower in women receiving efavirenz compared with women on non-efavirenz regimens or no antiretroviral therapy (p < .01). Serum estradiol was moderately and negatively correlated with efavirenz plasma (r = -0.36, p < .001) and CVF (r = -0.50, p < .001) concentrations. Serum estradiol was a significant predictor of efavirenz CVF concentrations even after adjusting for efavirenz plasma concentrations (p = .02). In upper-layer packed cells (ULPCs), tenofovir diphosphate (TFVdp) concentrations were similar between follicular and luteal phases and were not correlated with estradiol or progesterone concentrations. Tenofovir concentrations in CVF were not associated with menstrual cycle or serum hormone concentrations. In CVF and plasma, efavirenz concentrations were negatively correlated with serum estradiol concentrations, suggesting a modulatory effect of estradiol on efavirenz metabolism and/or transport processes, and/or an effect of efavirenz on the metabolism of estradiol. Differences in CVF persisted even after adjusting for plasma concentrations, suggesting a mechanism specific to the female genital compartment separate from absorption or hepatic metabolism. In contrast, TFVdp concentrations in ULPC were not influenced by endogenous estradiol or progesterone concentrations.

Brief Report: Impact of ART Classes on the Increasing Risk of Cerebral Small-Vessel Disease in Middle-Aged, Well-Controlled, cART-Treated, HIV-Infected Individuals.

BACKGROUND: Cerebral small-vessel disease (CSVD) is a chronic disease accounting for one-third of strokes and the second etiology of dementia. Despite sustained immunovirological control, CSVD prevalence is doubled in middle-aged persons living with HIV (PLHIVs), even after adjustment for traditional cardiovascular risk factors. We aimed to investigate whether exposure to any antiretroviral drug class could be associated with an increasing risk of CSVD. METHODS: The MicroBREAK-2 case-control study (NCT02210130) enrolled PLHIVs aged 50 years and older, treated with combined antiretroviral therapy for ≥5 years, with plasma HIV load controlled for ≥12 months. Cases were PLHIVs with radiologically defined CSVD, and controls were CSVD-free PLHIVs matched for age (±5 years), sex, and year of HIV diagnosis (±5 years). Multivariable conditional logistic regression analyses focused on cumulative exposure to nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors and/or exposure to integrase inhibitors (yes or no), adjusted for hypertension, CD4 nadir, current CD4/CD8 ratio, and HIV transmission group. RESULTS: Between May 2014 and April 2017, 77 cases and 77 controls (85.7% males) were recruited. PLHIVs' median age was 57.6 years, and median HIV diagnosis year was 1992. The increasing risk of CSVD was not associated with exposure to any ART class. CONCLUSION: No deleterious effect of ART class exposure on the risk of CSVD was found for middle-aged treated PLHIVs.

Predictors of electrocardiographic QT interval prolongation in men with HIV.

OBJECTIVE: HIV-infected (HIV+) individuals may be at increased risk for sudden arrhythmic cardiac death. Some studies have reported an association between HIV infection and prolongation of the electrocardiographic QT interval, a measure of ventricular repolarisation, which could potentiate ventricular arrhythmias. We aimed to assess whether HIV+ men have longer QT intervals than HIV-uninfected (HIV-) men and to determine factors associated with QT duration. METHODS: We performed resting 12-lead ECGs in 774 HIV+ and 652 HIV- men in the Multicenter AIDS Cohort Study (MACS). We used multivariable linear and logistic regression analyses to assess associations between HIV serostatus and Framingham corrected QT interval (QTc), after accounting for potential confounders. We also determined associations among QTc interval and HIV-related factors in HIV+ men. In a subgroup of participants, levels of serum markers of inflammation were also assessed. RESULTS: After adjusting for demographics and risk factors, QTc was 4.0 ms longer in HIV+ than HIV- men (p<0.001). Use of antiretroviral therapy (ART), specific ART drug class use and other HIV-specific risk factors were not associated with longer QTc. Among the subgroup with inflammatory biomarker measurements, higher interleukin-6 (IL-6), intercellular adhesion molecule-1 (ICAM-1) and B-cell activating factor levels were independently associated with longer QTc and their inclusion partially attenuated the HIV effect. CONCLUSIONS: HIV+ men had longer QTc, which was associated with higher levels of systemic inflammatory factors. This longer QTc may contribute to the increased risk for sudden arrhythmic cardiac death in some HIV+ individuals.

Risk of extensive virological failure to the three original antiretroviral drug classes over long-term follow-up from the start of therapy in patients with HIV infection: an observational cohort study.

BACKGROUND: The long-term durability of viral-load suppression provided by the three original antiretroviral drugs is not well characterised. We estimated the proportion of patients who had extensive triple-class failure during long-term follow-up and examined characteristics associated with an increased rate of failure. METHODS: 7916 patients who started antiretroviral therapy with three or more drugs were followed up from the time that therapy started until the last viral-load measure. Extensive triple-class virological failure was defined by failure of three subclasses of nucleoside reverse transcriptase inhibitors, a non-nucleoside reverse transcriptase inhibitor, and a ritonavir-boosted protease inhibitor. FINDINGS: 167 patients developed extensive triple-class failure during 27 441 person-years of follow-up. The Kaplan-Meier estimate for the cumulative risk of extensive triple-class failure was 9.2% by 10 years (95% CI 5.0-13.4). There was evidence that this rate has decreased over time (adjusted hazard ratio 0.86 [0.77-0.96] per year more recent; p=0.006). Of the 167 patients with extensive triple-class failure, 101 (60%) subsequently had at least one viral load less than 50 copies per mL. The risk of death by 5 years from the time of extensive triple-class failure was 10.6% (2.4-18.8, nine deaths). INTERPRETATION: We have shown that extensive virological failure of the three main classes of drugs occurs slowly in routine clinical practice. This finding has implications for the planning of treatment programmes in developing countries, where additional drugs outside these classes are unlikely to be available for some time.

HIV infection and complications in emergency medicine.

HIV infection is a common worldwide public health challenge affecting an estimated 40 million persons. In the United States, there have been over 900,000 cases of AIDS, and it is estimated that there are currently over 1 million HIV-infected persons in the United States. Although the population of HIV seropositivity is concentrated in large urban settings, infections have been documented in all states. Because of the widespread prevalence and serious health consequences, it is imperative that the emergency physician be knowledgeable and skilled to diagnose and manage HIV-related emergency conditions. Knowledge of clinical presentations, differential diagnosis, early treatment strategies, and disposition options is crucial to the effective emergency department management of HIV infections and AIDS.

Healthcare utilization of patients accessing an African national treatment program.

BACKGROUND: The roll-out of antiretroviral therapy (ART) in Africa will have significant resource implications arising from its impact on demand for healthcare services. Existing studies of healthcare utilization on HAART have been conducted in the developed world, where HAART is commenced when HIV illness is less advanced. METHODS: This paper describes healthcare utilization from program entry by treatment-naïve patients in a peri-urban settlement in South Africa. Treatment criteria included a CD4 cell count <200 cells/microl or an AIDS-defining illness. Data on health service utilization were collected retrospectively from the primary-care clinic and secondary and tertiary referral hospitals. Hospital visits were reviewed to determine the clinical reason for each visit. RESULTS: 212 patients were followed for a median of 490 days. Outpatient visits per 100 patient years of observation (PYO), excluding scheduled primary-care follow-up, fell from 596 immediately prior to ART to 334 in the first 48 weeks on therapy and 245 thereafter. Total inpatient time fell from 2,549 days per 100 PYO pre-ART to 476 in the first 48 weeks on therapy and 73 thereafter. This fall in healthcare utilization occurred at every level of care. The greatest causes of utilization were tuberculosis, cryptococcal meningitis, HIV-related neoplasms and adverse reactions to stavudine. After 48 weeks on ART demand reverted to primarily non-HIV-related causes. CONCLUSION: Utilization of both inpatient and outpatient hospital services fell significantly after commencement of ART for South African patients in the public sector, with inpatient demand falling fastest. Earlier initiation might reduce early on-ART utilization rates.

[Optimizing resources to reduce costs to determine HIV viral load in limited resources settings].

INTRODUCTION: HIV viral load testing is a key factor to evaluate the accomplishment of the UNAIDS target of 90% of viral suppression among people receiving antiretroviral therapy. Pooled samples are a potentially accurate and economic approach in resource-constrained settings, but efficiency can be negatively affected by high prevalence rates of virological failure. OBJECTIVE: Strategies were assessed to increase the relative efficiency of pooled HIV viral load testing in resource-constrained settings. MATERIALS AND METHODS: We evaluated two strategies: a) plasma samples were not included in pools if patients had <12 months on antiretroviral therapy, patients had previous viral load >1,000 copies/ml, or were antiretroviral therapy naïve patients, and b) plasma pools were organized separately for first and second-line antiretroviral therapy regimens. Individual viral load tests were used to compare pooled results. RESULTS: Negative predictive values were similar for patients on first (100.0%; 95% CI 99.5 to 100.0) and second-line antiretroviral therapy regimens (99.4%; 95% CI 96.9 to 99.9). However, the incidence of virological failure among individuals on first-line antiretroviral therapy was lower than second-line antiretroviral therapy patients (p <0.01), resulting in greater savings in laboratory tests in patients on first-line antiretroviral therapy (74.0%; 95% CI 71.0 to 76.7) compared with the group of patients on second-line antiretroviral therapy (50.9%; 95% CI 44.4 to 57.3) (p<0.01). CONCLUSION: Selecting the samples to be included in the pools and selecting the pools according to ART regimens are criteria that could lead to decreased spending on laboratory tests for HIV viral load determination in resource-constrained settings.

Limitations of current antiretroviral agents and opportunities for development.

Significant progress has been made in the field of human immunodeficiency virus (HIV) pharmacotherapy. This is a remarkable achievement given that the virus was first recognized in the United States in 1981 and the first antiretroviral (ARV) agent became available in 1987. There are now 20 medications in 4 different classes approved by the Food and Drug Administration (FDA) for the treatment of HIV and the carefully orchestrated use of these agents has dramatically decreased HIV mortality. However, the currently available agents have concerning limitations. These include potentially life-threatening side effects, drug interactions, loss of effectiveness over time due to resistance and the need for an extremely high level of medication adherence to achieve viral suppression. In the following review, important features of the presently available agents are described, and the characteristics of an ideal ARV agent defined.

Understanding and avoiding antiretroviral adverse events.

UNLABELLED: To discuss prevention and management of adverse drug reactions which result from antiretroviral use in patients infected with HIV. There are four classes of antiretroviral agents used in the treatment of HIV/AIDS. Side effects to medications are common place and often difficult to avoid. In many cases, research is not able to identify the exact cause of an event. The severity of adverse reactions varies greatly, and some may be difficult to manage; typically, prevention is more desirable than treatment. However, this is not always true. This paper will review class-wide and individual side effects from antiretrovirals and, in some cases, the mechanism of action that results in the event. Class-wide side effects for nucleoside/tide reverse transcriptase inhibitors (NRTIs) include lactic acidosis, peripheral neuropathy and lipoatrophy. Adverse reactions from individual NRTIs, such as abacavir-induced hypersensitivity reactions, will also be discussed. Class-wide side effects to non-nucleoside reverse transcriptase inhibitors include rash and hepatotoxicity, while efavirenz has its own unique CNS reactions. Protease inhibitor side effects include hyperglycemia, lipoaccumulation, dyslipidemia, and gastrointestinal (GI) intolerance. We will also review specific side effects caused by indinavir, ritonavir, and atazanavir. Finally, adverse reactions from the fusion inhibitor, enfuvirtide, will be mentioned. CONCLUSION: Antiretrovirals are an important break-through in the treatment of HIV/AIDS. However, adverse reactions from these drugs can range from mild to life-threatening, and determining which agent is the cause is frequently difficult to discern. Fortunately, side effects can be monitored, treated and in many cases, prevented.

On the horizon: promising investigational antiretroviral agents.

Human immunodeficiency virus (HIV) infection affects close to 40 million individuals worldwide. Since 1981 when the first case reports of individuals dying from a then rare opportunistic infection were published, twenty million people have died from this epidemic. With 3 or more antiretrovirals as the standard of care, the prevalence of single, double and triple-class resistant HIV strains has increased significantly over the last 5 years due to the tremendous replicative capacity of HIV and selective drug pressure. With greater resistance comes the need for novel and effective antiretrovirals to treat these resistant strains. The purpose of this review is to highlight the most promising agents and classes in Phase II-III drug development by assessing the clinical efficacy, pharmacology, resistance and tolerability. Three out of the four existing antiretroviral classes (nucleosides, non-nucleosides, protease inhibitors) with agents in clinical trials will be discussed such as nucleoside reverse transcriptase inhibitors (D-d4FC, SPD754), non-nucleoside reverse transcriptase inhibitors (capravirine, TMC125) and protease inhibitors (tipranavir, TMC114). In the next several years, antiretrovirals from novel pharmacologic classes will enter the HIV armamentarium. Based on the early clinical studies, these promising agents will be reviewed from the following classes: attachment inhibitors (TNX-355, BMS-488043), CCR5 coreceptor antagonists (SCH-D, UK-427857, GW 873140) and a maturation inhibitor (PA-457). It is hoped that these agents will represent a therapeutic advance and better activity against HIV resistant strains by providing effective therapy that will reduce viral load, increase the CD4+ cell count and ultimately, prolong survival with minimal adverse effects.

Antiretroviral therapy in HIV.

The advent of highly active antiretroviral therapy (HAART) has led to a significant decline in HIV-associated morbidity and mortality. Despite these recent advances, the majority of patients with HIV/AIDS worldwide are still lacking access to treatment. To date, there are 21 approved antiretrovirals divided into four categories based on their mechanism of action. We review the basic characteristics of these antiretrovirals. We also briefly discuss current guidelines regarding the use of antiretrovirals in general as well as in special populations such as in pregnant women, in occupational exposure and non occupational exposure.

Projected Uptake of New Antiretroviral (ARV) Medicines in Adults in Low- and Middle-Income Countries: A Forecast Analysis 2015-2025.

With anti-retroviral treatment (ART) scale-up set to continue over the next few years it is of key importance that manufacturers and planners in low- and middle-income countries (LMICs) hardest hit by the HIV/AIDS pandemic are able to anticipate and respond to future changes to treatment regimens, generics pipeline and demand, in order to secure continued access to all ARV medicines required. We did a forecast analysis, using secondary WHO and UNAIDS data sources, to estimate the number of people living with HIV (PLHIV) and the market share and demand for a range of new and existing ARV drugs in LMICs up to 2025. UNAIDS estimates 24.7 million person-years of ART in 2020 and 28.5 million person-years of ART in 2025 (24.3 million on first-line treatment, 3.5 million on second-line treatment, and 0.6 million on third-line treatment). Our analysis showed that TAF and DTG will be major players in the ART regimen by 2025, with 8 million and 15 million patients using these ARVs respectively. However, as safety and efficacy of dolutegravir (DTG) and tenofovir alafenamide (TAF) during pregnancy and among TB/HIV co-infected patients using rifampicin is still under debate, and ART scale-up is predicted to increase considerably, there also remains a clear need for continuous supplies of existing ARVs including TDF and EFV, which 16 million and 10 million patients-respectively-are predicted to be using in 2025. It will be important to ensure that the existing capacities of generics manufacturers, which are geared towards ARVs of higher doses (such as TDF 300mg and EFV 600mg), will not be adversely impacted due to the introduction of lower dose ARVs such as TAF 25mg and DTG 50mg. With increased access to viral load testing, more patients would be using protease inhibitors containing regimens in second-line, with 1 million patients on LPV/r and 2.3 million on ATV/r by 2025. However, it will remain important to continue monitoring the evolution of ARV market in LMICs to guarantee the availability of these medicines.

Polypharmacy in HIV: impact of data source and gender on reported drug utilization.

Drug use in HIV is complex and may involve multiple therapeutic and nontherapeutic agents including prescription, over-the-counter, complementary and alternative medicine, and social/recreational drugs. This study was designed to assess the extent of such drug use in HIV-infected men and women. One hundred four adults were recruited through the HIV Ontario Observational Database from HIV outpatient clinics throughout Ontario, Canada. Patient demographics and data on drug use and physician awareness of drug use were collected through in-person interviews and medical chart review. All patient interviews and 96% of medical charts revealed the use of at least one drug. Eighty-five percent of patients reported use of antiretroviral medications; nearly 70% used highly active antiretroviral therapy. Patients used significantly more drugs by patient report (15.7 +/- 7.7) than by medical chart review (8.4 +/- 5.0) reporting up to 39 drugs per person. Pill burden was substantial, averaging 20.7 +/- 12.5 and ranged up to 69 "pills-per-day." Patient-reported physician awareness of drug use was highest for prescription drugs and lowest for social/recreational drugs; correspondingly agreement between medical chart and patient report ranged from 80% for antiretrovirals to 10% for non-prescribed drugs. The drug and pill burden faced by patients with HIV is considerable. Prevalence of use for specific drug classes varied with both data source and gender while number of drugs used differed only by data source. Our findings emphasize the complexity of pharmacotherapy in HIV and the need for comprehensive drug assessment, particularly because of the risks of drug-drug interactions and decreased adherence secondary to therapeutic complexity.

[New antiretroviral medications in therapy of HIV infections]. / Nowe leki antyretrowirusowe w leczeniu zakazen HIV.

Therapeutic options continue to expand with the development of new drugs and new strategies for using them. This report describes progress in laboratory and clinical trials of new inhibitors of reverse transcriptase and viral protease, turning special attention on their efficacy for therapy of patient with drug resistant viruses for current therapies. The second group is a new class of anti-HIV drugs called "fusion inhibitors" or "viral entry inhibitors" The fusion inhibitors halt HIV at a unique point in the virus life cycle blocking attachment of virus to the membrane of target cells. All of the described drugs are not potent enough to eradicate the virus. Diminished toxicity of proposed new antiretroviral substances, more tolerable regimens easier for patients and efficacy against resistant viruses to currently used drugs are giving hope for further prolongation of life of HIV infected patients.