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.

Riesgo de enfermedad cardiovascular en pacientes con infección VIH en tratamiento antirretroviral / Risk of cardiovascular disease in patients with HIV infection undergoing antiretroviral therapy

ANTECEDENTES: La mayor supervivencia de los pacientes con infección por VIH gracias al tratamiento antirretroviral (TAR) se acompaña de una mayor frecuencia de enfermedad cardiovascular (ECV). Analizamos la prevalencia de los factores de riesgo cardiovascular (FRCV) y la estimación del riesgo de ECV en una cohorte de personas con infección por VIH en España. MÉTODOS: Estudio transversal, observacional de los FRCV en la cohorte española VACH de pacientes con infección por VIH que recibían TAR. RESULTADOS: Se evaluaron 15.559 pacientes con infección por VIH (76% varones; edad media: 46 años). Un 3,7% había experimentado al menos un evento de ECV. La prevalencia de FRCV era elevada: hiperlipidemia, 64%; tabaquismo, 47%; HTA, 22%; y diabetes, 16%. Según la escala Framingham, un 10,9% presentaba alto riesgo de ECV y un 28,8% riesgo moderado. De los pacientes con elevado riesgo de ECV, el 49% recibía inhibidores de proteasa y el 43% abacavir. Se usaron fármacos hipotensores en el 53% de los pacientes con diagnóstico de HTA, y fármacos antidiabéticos en el 2,6% de los pacientes con diabetes. CONCLUSIONES: Los FRCV tradicionales son frecuentes en los pacientes con infección por VIH con TAR en España, y una elevada proporción de ellos tiene riesgo moderado-alto de ECV. Por tanto, el control de los FRCV modificables en los pacientes con infección por VIH debería mejorarse y valorar el uso de fármacos con mejor perfil de riesgo cardiovascular

BACKGROUND: The increased survival of patients with HIV infection thanks to antiretroviral therapy (ART) is accompanied by a higher rate of cardiovascular disease (CVD). We analysed the prevalence of the cardiovascular risk factors (CRFs) and estimated the risk of CVD in a cohort of patients with HIV in Spain. METHODS: We conducted a cross-sectional, observational study of CRFs in the Spanish VACH cohort of patients with HIV who undergo ART. RESULTS: The study assessed 15,559 patients with HIV (76% men; mean age, 46 years). Some 3.7% had experienced at least 1 CVD event. The prevalence of CRFs was high (hyperlipidaemia, 64%; tobacco use, 47%; arterial hypertension, 22%; and diabetes, 16%). According to the Framingham scale, 10.9% of the patients presented a high CVD risk, and 28.8% presented a moderate risk. Of the patients with a high CVD risk, 49% took protease inhibitors and 43% took abacavir. Fifty-three percent of the patients diagnosed with arterial hypertension took antihypertensive drugs, and 2.6% of the patients with diabetes took antidiabetic agents. CONCLUSIONS: Classical CRFs are common in patients with HIV undergoing ART in Spain, and a large proportion of them have a moderate-high risk of CVD. Therefore, controlling the modifiable CRFs in patients with HIV should be improved, and the use of drugs with a better cardiovascular risk profile should be assessed

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.

Optimización de recursos para determinar la carga viral de HIV-1 en un país con pocos recursos / Optimizing resources to reduce costs to determine HIV viral load in limited resources settings

Resumen Introducción. Las metas globales para controlar la epidemia de HIV contemplan que la carga viral sea indetectable en 90 % de las personas en tratamiento. El costo de la medición de la carga viral en lotes de muestras puede reducirse y, así, aumentar la cobertura cuando los recursos son limitados; sin embargo, su eficacia disminuye al aumentar la prevalencia del fracaso del tratamiento antirretroviral. Objetivo. Evaluar estrategias para disminuir la proporción de pacientes con fracaso del tratamiento antirretroviral en los lotes de muestras y, de esta manera, aumentar el ahorro en las pruebas de carga viral. Materiales y métodos. Las estrategias evaluadas fueron: a) la organización de los lotes de muestras según el esquema de tratamiento antirretroviral, y b) la exclusión de aquellos pacientes con antecedente reciente de fracaso del tratamiento antirretroviral, aquellos con menos de 12 meses de tratamiento antirretroviral y aquellos sin tratamiento antirretroviral previo. Los resultados de los lotes se compararon con los resultados individuales. Resultados. El valor diagnóstico negativo fue similar para los pacientes con esquema de primera línea (100,0 %; IC95% 99,5-100,0) o de segunda línea de tratamiento (99,4 %; IC95% 96,9-99,9). La incidencia del fracaso del tratamiento antirretroviral fue menor en los pacientes con tratamiento de primera línea (p<0,01), lo cual permitió un mayor ahorro en las pruebas de laboratorio en este grupo (74,0 %; IC95% 71,0-76,7) que en los pacientes con tratamiento de segunda línea (50,9 %; IC95% 44,4-57,3) (p<0,01). Conclusión. La selección de las muestras que se incluyeron en los lotes para determinar la carga viral del HIV según el tipo de esquema de tratamiento, permitió maximizar el porcentaje de ahorro en pruebas de laboratorio.

Abstract 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 therapypatients (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.

[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.

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.

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.

Terapia antirretroviral del AIDS en adultos mayores de 50 años: prevalencia y clasificación de los no adherentes / AIDS Antiviral Therapy in adults over 50 years old: non adherents’ prevalence and classification

Objetivo: Analizar la adherencia al terapia antirretroviral, a partir de la determinación de las variables de clasificación de los no adherentes, según las variables de comportamiento, y de la definición de la prevalencia de no adhesión en los adultos mayores de 50 años, atendidos en el Hospital Universitario Santa Maria / RS. Método: Investigación de enfoque cuantitativo, tipo descriptivo y transversal. La población de estudio estaba formado por pacientes mayores de 50 años que tienen el HIV / AIDS, y que estaban bajo tratamiento en HUSM, por un total de 72 pacientes. La recolección de datos se desarrolló en el periodo de abril de 2009 hasta octubre de 2010. Se realizaron análisis univariado (porcentajes de frecuencia) y bivariado, cruzando el resultado (cumplimiento del TARV) y las variables de comportamiento de la clasificación de no adherentes, por medio del test de chi-cuadrado. Resultados: La población de pacientes no adherentes fue de 21, con una prevalencia de incumplimiento del 29,2%. A partir del análisis bivariado fue posible determinar las variables de comportamiento para la clasificación de no adherentes: por alguna razón no tomó alguna de las dosis, deje de tomar los medicamentos por el consumo de alcohol, los efectos secundarios impidieron tomar alguna dosis del medicamento, no tomó el medicamento durante el tiempo que estaba trabajando. Conclusiones: Después de identificar la prevalencia de no adhesión al TARV, y la determinación de las variables que determinan la clasificación de los no adherentes, se pudo conocer la población de no adherentes y las variables de comportamiento que indican esta capacidad para la no ingestión del 100% de las dosis prescritas(AU)

Objective: To analyze the antiretroviral therapy adherence, from the determination of non-adherents’ classification variables, according behavior variables, and over 50 year old adults’ non-adherence prevalence definition, treated at Santa Maria University Hospital (SMUH), RS. Method: This research presents a quantitative approach, descriptive type and cross-sectional design. This study’s population was patients with age above 50 years old that have aids that were treated in SMUH, total of 72 patients. Data collection was developed from April 2009 to October 2010. We performed univariate (frequency percentages) and bivariate analysis, crossing the outcome (ART adherence) and behavioral variables for classification of non-adherents through the chi-square. Results: Non-adherents’ population was 21 patients, with non-adherence prevalence of 29,2%. From bivariate analysis, it was possible to determinate non-adherents’ behavior variables classification: for some reason didn’t take any of the doses; stopped taking medicines for alcoholic use; side effects prevented from taking any of the medicine doses; didn’t take this medicine during working hours. Conclusions: After defining ART prevalence and non-adherents’ behavior variables classifications determinations, it was possible to know the non adherents’ population and behavior variables that indicates this potentiality to non ingestion of 100% prescribed doses(AU)

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.

Medical consequences of drug abuse and co-occurring infections: research at the National Institute on Drug Abuse.

Substance abuse still remains one of the major problems in the world today, with millions of people abusing legal and illegal drugs. In addition, a billion people may also be infected with one or more infections. Both drugs of abuse and infections are associated with enormous burden of social, economic, and health consequences. This article briefly discusses a few medical consequences of drugs of abuse and infections such as human immunodeficiency virus, hepatitis C virus, psychiatric complications in hepatitis C infection, pharmacokinetic drug-drug interactions among medications used in the treatment of addiction and infections, and new drugs in development for the treatment of infections. Research is encouraged to study interactions between infections, drugs of abuse, and underlying pathophysiologic and molecular/genetic mechanisms of these interactions.

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.

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.

Advances in pharmacogenomics of antiretrovirals: an update.

Recent developments in the pharmacogenomics of antiretroviral drugs provide new prospects for predicting the efficacy of treatment and potential adverse effects. HIV/AIDS is a serious but treatable infectious disease, yet current treatment is limited by high rates of adverse drug reactions and development of resistance due to suboptimal drug concentrations in a significant proportion of patients. Antiretroviral therapy is especially suitable for pharmacogenomic investigation as both drug exposure and treatment response can be quantified and certain adverse effects can be assessed with validated measures. Additionally, there is increasing knowledge of the pharmacokinetics and dynamics of antiretroviral drugs, and some candidate genes implicated in the metabolism, transport and adverse effects have been identified. However, recent studies of the association of particular genes and their genetic variants with HIV management and adverse drug reactions have not provided unifying conclusions. This article reviews the most recently published work and summarizes the state of research in this area. Future directions for research and the application of this technology to the clinical practice of individualizing treatment for HIV management are discussed.

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.

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.