Low frequency of hypersensitivity reactions to abacavir in HIV infected patients in a referral center in Bahia, Brazil

Abstract Abacavir can cause a multi-systemic hypersensitivity reaction (HSR) in 5-8% of the patients, which is related to HLA-B*57-01 allele. In Brazil, the HLA-B*57-01 screening test became available only in March 2018, several years after abacavir was in use. In this retrospective study we reviewed medical charts of all patients receiving an abacavir-containing regimen to evaluate the frequency of HSR in patients followed at a referral center in Salvador, Brazil. A total of 192 patients who received abacavir were identified, most male (67.1%), black or racially mixed (77.8%), and having diagnosis of a previous AIDS defining conditions (83.7%). Only one patient developed HSR (incidence: 0.52%). The main reasons for abacavir-containing antiretroviral therapy discontinuation were virological failure (28%), adverse effects to other components of the regimen (25%), and simplification of therapy (16%). The low incidence of HSR to abacavir does not support the use of HLA-B*57-01 screening test, in Salvador, Brazil.

Hypertension Risk with Abacavir Use among HIV-Infected Individuals: A Nationwide Cohort Study

PURPOSE: A high risk of cardiovascular disease (CVD) is reported for HIV-infected individuals. While a link between abacavir and CVD risk is suggested, an association between abacavir and hypertension remains unclear. This study evaluated hypertension risk with abacavir use in comparison to non-abacavir antiretroviral treatment (ART). MATERIALS AND METHODS: From a nationwide cohort of HIV-infected individuals on their initial ART, 6493 who were free of hypertension at baseline were analyzed. The use of ART was treated as a time-varying covariate measured as a daily unit. Incidence rate of hypertension was calculated, and Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) with 95% confidence interval (CI) of incident hypertension overall and among subgroups. RESULTS: From the 6493 participants, 24072 person-years (PY) of follow-up were contributed during 2008–2016. The incidence rates of hypertension were 4.6 and 3.6 per 100 PY for abacavir and non-abacavir ART users, respectively. The population attributable fraction of abacavir use on hypertension was 12%. Abacavir exposure did not elevate the risk of hypertension among overall study population [HR, 1.2 (95% CI, 1.0–1.4), p=0.061]. However, those with poor ART adherence, defined as a medication possession ratio < 50% [HR, 1.9 (95% CI, 1.5–2.4), p < 0.0001] or requiring prophylactic antibiotics [HR, 1.2 (95% CI, 1.0–1.3), p=0.023], were at risk of hypertension induced by abacavir, as were men, individuals aged ≥40 years, and patients visiting tertiary hospitals in urban areas. CONCLUSION: When present, poor ART adherence, requiring prophylactic antibiotics, male sex, and older age may warrant additional concern for hypertension in patients treated with abacavir.

Zidovudine/Lamivudine vs. Abacavir/Lamivudine vs. Tenofovir/Emtricitabine in fixed-dose combinations as initial treatment for HIV patients: a systematic review and network meta-analysis / Zidovudina/Lamivudina vs Abacavir/Lamivudina vs Tenofovir/Emtricitabina en combinaciones de dosis fija como tratamiento inicial en pacientes con VIH: revisión sistemática y metanálisis en red

Abstract Introduction: Initial treatment of the HIV is based on the use of three drugs, two of which are nucleoside analog reverse-transcriptase inhibitors. There are three combinations of these drugs which have been approved by different guidelines, each with divergent results in terms of efficacy and safety. Objective: To compare the efficacy and safety of these three combinations. Methods: Systematic review and network meta-analysis of randomized clinical trials comparing fixed doses of Tenofovir Disoproxil Fumarate / Emtricitabine (TDF/FTC), Abacavir / Lamivudine (ABC/3TC) and Zidovudine / Lamivudine (ZDV/3TC). Results: Seven clinical trials met the eligibility criteria. The results suggested higher efficacy with TDF/FTC vs. ABC/3TC at 96 weeks and vs. ZDV/3TC at 48 weeks. However, there is clinical and statistical heterogeneity. Subgroup analysis were performed by third drug and by level of viral load prior to treatment, and found no differences in virological control. Network meta-analysis could only be carried out with TDF/FTC vs. ZDV/3TC, and the proportion of patients with virological response, with no differences at 48 weeks nor at 96 weeks. Direct comparisons showed an increased risk of bone marrow suppression of ZDV/3TC vs. TDF/FTC and of ABC/3TC hypersensitivity reactions vs. ZDV/3TC Conclusions: The results did not show differences in effectiveness among the interventions. However, due to the heterogeneity of the third drug and the follow-up time between the included studies, this result is not definitive. The results raise the need for further studies to help improve treatment recommendations in patients infected with HIV.

Resumen Introducción: El tratamiento inicial de la infección por VIH se basa en el uso de tres medicamentos, dos de ellos inhibidores de transcriptasa reversa análogos de nucleósido. Existen tres combinaciones de estos medicamentos aprobadas por diferentes guías, con resultados divergentes en cuanto a eficacia y seguridad. Objetivo: Comparar la eficacia y seguridad de las 3 combinaciones Métodos: Revisión sistemática y metanálisis en red de ensayos clínicos con asignación aleatoria comparando dosis fijas de Tenofovir Disoproxil Fumarato/Emtricitabina (TDF/FTC), Abacavir/Lamivudina (ABC/3TC) y Zidovudina/Lamivudina (ZDV/3TC). Resultados: Siete ensayos clínicos cumplieron los criterios de elegibilidad. Los resultados sugirieron mayor eficacia con TDF/FTC vs ABC/3TC a 96 semanas y vs. ZDV/3TC a 48 semanas. Sin embargo, existe heterogeneidad clínica y estadística. Se realizó análisis de subgrupos por tercer medicamento y por nivel de carga viral previa al tratamiento, sin encontrar diferencias en control virológico. Se pudo realizar metanálisis en red con TDF/FTC vs ZDV/3TC y proporción de pacientes con respuesta virológica, sin diferencias a las 48 semanas ni 96 semanas. Las comparaciones directas evidenciaron mayor riesgo de supresión de médula ósea de ZDV/3TC vs TDF/FTC y de reacciones de hipersensibilidad de ABC/3TC vs ZDV/3TC. Conclusión: Los resultados no demostraron diferencias en efectividad entre las intervenciones; sin embargo, debido a heterogeneidad en cuanto al tercer medicamento y el tiempo de seguimiento entre los estudios incluidos, dicho resultado no es definitivo. Los resultados plantean la necesidad de realizar nuevos estudios que ayuden a mejorar las recomendaciones de tratamiento en los pacientes infectados por el VIH.

Safety and Efficacy of Ziagen (Abacavir Sulfate) in HIV-Infected Korean Patients

BACKGROUND: Abacavir is a widely-used nucleoside reverse transcriptase inhibitor for the treatment of human immunodeficiency virus (HIV) infection. Mandatory postmarketing surveillance was conducted in Korea to monitor the safety and evaluate the effectiveness of Ziagen® (abacavir sulfate 300 mg; ViiV Healthcare, Middlesex, UK). MATERIALS AND METHODS: An open-label, multi-center, non-interventional postmarketing surveillance study was conducted from June 2010 to June 2016 to monitor the safety and effectiveness of Ziagen across 12 hospitals in Korea. Subjects older than 18 years taking Ziagen according to prescribing information were enrolled. The primary outcome was defined as the occurrence of any adverse events after Ziagen administration. Secondary outcomes included the occurrence of adverse drug reactions, occurrence of serious adverse events, and effectiveness of Ziagen administration. RESULTS: A total of 669 patients were enrolled in this study, with a total observation period of 1047.8 person-years. Of these, 90.7% of patients were male. The mean age of patients was 45.8±11.9 years. One-hundred ninety-six (29.3%) patients reported 315 adverse events, and four patients reported seven serious adverse events, without any fatal events. There was one potential case of an abacavir hypersensitivity reaction. Among the 97 adverse drug reactions that were reported from 75 patients, the most frequent adverse drug reactions included diarrhea (12 events), dyspepsia (10 events), and rash (9 events). No ischemic heart disease was observed. In the effectiveness analysis, 91% of patients achieved HIV-1 RNA under 50 copies/mL after 24 months of observation with abacavir administration. CONCLUSION: Our data showed the safety and effectiveness of Ziagen in a real-world setting. During the study period, Ziagen was well-tolerated, with one incident of a clinically suspected abacavir hypersensitivity reaction. The postmarketing surveillance of Ziagen did not highlight any new safety information. These data may be helpful in understanding abacavir and the HIV treatment practices in Korea.

Abacavir-induced liver toxicity

Abstract Abacavir-induced liver toxicity is a rare event almost exclusively occurring in HLA B*5701-positive patients. Herein, we report one case of abnormal liver function tests occurring in a young HLA B*5701-negative woman on a stable nevirapine-based regimen with no history of liver problems or alcohol abuse after switching to abacavir from tenofovir. We also investigated the reasons for abacavir discontinuation in a cohort of patients treated with abacavir-lamivudine-nevirapine.

Abacavir: una revisión actualizada sobre sus propiedades y aplicaciones / Abacavir: an updated review on its properties and applications

El Plan Estratégico Nacional para la Prevención y Control de las ITS/VIH/sida, 2014-2018 en Cuba establece un grupo de acciones entre las que se encuentra la estandarización y optimización de esquemas de terapia antirretroviral, adecuación del inicio del tratamiento a las recientes recomendaciones de la Organización Mundial de la Salud, mejorar la calidad de la atención, la adherencia y la reducción del costo de los medicamentos. Para cumplir estas tareas se prevé introducir en el Cuadro Básico de Medicamentos algunos antirretrovirales genéricos cubanos para incrementar las posibles combinaciones de Terapia Antirretroviral de Alta Eficacia a disposición de los pacientes que viven con el virus de la inmunodeficiencia humana y sustituir importaciones. Se realizó una revisión bibliográfica exhaustiva para la actualización de la comunidad médica y científica; se examinaron las principales características del abacavir: propiedades químico-físicas del principio activo, sus presentaciones comerciales, mecanismo de acción, farmacocinética y resistencia, reacciones adversas e interacciones, aplicaciones terapéuticas, dosificaciones, ajustes de dosis y seguridad en el embarazo. Para ello se consultaron un total de 58 artículos que incluyeron revisiones bibliográficas, trabajos originales, fichas técnicas, libros, conferencias y reportes. El abacavir es un antirretroviral relativamente nuevo y ampliamente recomendado por las guías de tratamiento por su efectividad demostrada(AU)

The National Strategic Plan for the Prevention and Control of the IST/HIV/ aids, 2014-2018 in Cuba establishes a group of actions such as the standardization and optimization of antiretroviral therapy schedules, adaptation of the beginning of the treatment to the recent recommendations of the World Health Organization, the improvement of the quality of care, the adherence to and the reduction of the cost of medications. For the purpose of complying with these tasks, it is anticipated to introduce in the basic drug listing some Cuban generic antiretroviral drugs to increase the possible combinations of the Highly Active Antiretroviral Therapy available for patients who live with the human immunodeficiency virus and to reduce imports. An exhaustive literature review was made for the update of the medical and scientific community knowledge. This article analyzed the main characteristics of abacavir such as chemical-physical properties of the active principle, their commercial presentations, mechanism of action, pharmacokinetics and resistance, adverse reactions and interactions, therapeutic applications, dosages, dose adjustments and safety at pregnancy. To this end, a total of 58 articles were consulted including literature reviews, original papers, technical records, books, lectures and reports. Abacavir is a relatively new antiretroviral, widely recommended by treatment guidelines on account of its proven effectiveness(AU)

Implementación del estudio farmacogenético de hipersensibilidad al abacavir HLA-B*5701 en Argentina / Implementation of pharmacogenetic study HLA-B*5701 to predict abacavir hipersensitivity in Argentina

El abacavir (ABC) es un antirretroviral inhibidor de la transcriptasa reversa del virus HIV-1 que está fuertemente asociado al desarrollo de reacciones de hipersensibilidad en individuos portadores del alelo HLA-B*5701. Objetivos: determinar la prevalencia del alelo HLA-B*5701 en pacientes HIV-1 positivos y en una población control de Argentina. Materiales y métodos: desde enero de 2012 hasta octubre de 2013 se estudiaron 869 pacientes HIV-1 positivos y 63 individuos no infectados con HIV-1. La detección del alelo HLA-B*5701 se realizó mediante un ensayo in house basado en la técnica de PCR en tiempo real, diseñado en nuestro laboratorio y validado según guías internacionales. Resultados: el primero de enero se implementó el estudio farmacogenético para la detección de hipersensibilidad al ABC en los pacientes incluidos en el Programa VIH/sida de la Dirección de SIDA y ETS, y en los niños infectados con HIV-1 del Hospital Garrahan. Para ello se adoptó un protocolo de envío, recepción y procesado de las muestras, con un informe detallado de los resultados. El alelo HLA-B*5701 se detectó en 42 individuos infectados con HIV-1 y en 3 individuos no infectados. Conclusiones: la prevalencia del alejo HLA-B*5701 en la población de pacientes infectados con HIV-1 y la población control fue la misma (4,8%), lo cual sugiere que la presencia de este alelo no influye en la infección por HIV-1. Esta prevalencia fue similar a la reportada para otras poblaciones de origen caucásico...

Alopecia Areata Associated with Abacavir Therapy

Abacavir is a nucleoside reverse-transcriptase inhibitor that has been approved for use in combination with other retroviral agents in the treatment of HIV infection. Common adverse reactions include headache, fatigue, nausea, and rash. A fatal hypersensitivity reaction may occur in 5% of patients receiving abacavir; therefore, screening for HLA-B5701 should be performed before starting abacavir. Alopecia areata (AA) is infrequently reported in HIV-infected patients. Certain underlying conditions have been associated with AA, including a decreased CD4:CD8 ratio related to the progression of HIV infection, some opportunistic infections, and syphilis. Several antiretroviral drugs, such as zidovudine, indinavir, indinavir/ritonavir, lopinavir/ritonavir, and atazanavir/ritonavir have been implicated in the development of AA. At present, the occurrence of AA has not been associated with abacavir use. We cannot exclude that the use of abacavir and the development of AA could be coincidental. Nevertheless, patients given abacavir should be monitored for hair loss and the drug discontinued promptly if such signs appear.

Prevalence and Risk Factors of Low Bone Mineral Density in Korean HIV-Infected Patients: Impact of Abacavir and Zidovudine

Low bone mineral density (BMD) is common in HIV-infected patients. We aimed to describe the prevalence of low BMD and risk factors in Korean HIV-infected patients and to assess the effects of antiretroviral therapy (ART) on BMD. We retrospectively evaluated 224 HIV infected-patients. The prevalence of osteopenia and osteoporosis were 41.5% and 12.9%. These were much higher in 53 patients aged 50 yr and older (52.8% and 34.0%). Older age, lower body mass index, and ART > 3 months were independent risk factors for low BMD. Osteoporosis was more prevalent in patients on the abacavir-based regimen for or = 1 yr; however, it was more prevalent in patients on the zidovudine-based regimen for > or = 1 yr than < 1 yr (P = 0.017). Osteoporosis in patients on the abacavir-based regimen was more common in the spine than in the femur (P = 0.01). Given such a high prevalence of low BMD, close monitoring of BMD for HIV-infected patients on ART is required. The different prevalence of osteoporosis over time and affected areas between two regimens suggest they may play roles in different mechanisms in bone loss.

Analytical Method Development and Validation of Anti-HIV Drug Abacavir Sulphate.

Analytical method development and validation was useful for estimation of drugs in bulk and biological fluids. They help to improve the reliability, consistency and accuracy of analytical data. Present investigation involves development and validation of UV spectroscopic method for abacavir sulphate as per ICH guidelines. The present work describes sensitive and robust method development of abacavir sulphate by UV spectroscopic method for estimation of abacavir sulphate in bulk and pharmaceutical dosage forms using UV-1700 pharma spec (Shimadzu). The method was validated for accuracy, precision, linearity, ruggedness and robustness to check its consistency. The wavelength scan of UV spectroscopic method showed absorption maxima 249 nm obeying beers law with linearity range of 0-40μg/ml and correlation coefficient of 0.99939. Molar absorptivity and sandell’s sensitivity are found to be 1.2404472 ×10-4 and 0.0208 respectively. The accuracy was found to be 99.94%-100.2% with recovery 99.76%, 100.06%, 100.07% for 50%, 100%, 150% solutions. The obtained results indicated that the developed analytical method was sensitive, accurate, with low standard deviation values for all validation parameters and could be used in day to day regular analysis of abacavir sulphate in bulk and pharmaceutical formulations.

The First Case of Abacavir Hypersensitivity Associated with the HLA-B*57:01-Positive Allele in Korea

On the 12th day of abacavir treatment, a 39-year old HIV-infected male patient was admitted with fever, generalized rash, abdominal pain, and watery diarrhea that had persisted for five days. Results of blood tests indicated rapid progression of hepatitis and renal failure. The day after stopping anti-retroviral therapy, his fever subsided and his liver function began to normalize. He was clinically diagnosed with abacavir hypersensitivity and was found to carry the HLA-B*57:01 allele. This is the first reported case of abacavir hypersensitivity associated with the presence of the HLA-B*57:01 allele in Korea.

A Case of Hypersensitivity Reaction Induced by Abacavir in an AIDS Patient / 대한내과학회지

Abacavir is a nucleoside reverse transcriptase inhibitor that is commonly used in HIV-infected patients. A well-known and potentially life-threatening side effect of abacavir is allergic hypersensitivity reaction. A screening test for the HLA-B*5701 allele is currently used to predict the risk of hypersensitivity reaction to abacavir. This test, however, may be less useful in Korea, because of the low prevalence of HLA-B*5701. A 52-year-old male with HIV infection was referred to our hospital because of suspected side-effects of antiviral agents and lymph node enlargement of the neck. He suffered from a fever, generalized edema, skin rash of the whole body, and difficulty breathing after starting antiviral agents. Suspected as a hypersensitivity reaction resulting from drug side-effects, prescription of abacavir was stopped. The patient subsequently recovered. The presence of the HLA-B*5701 allele was confirmed by polymerase chain reaction-sequencing based typing (PCR-SBT).

HLA-B*5701 frequency in Chilean HIV-infected patients and in general population

It has been demonstrated that HLA-B*5701 screening reduces the risk for hypersensitivity reaction to abacavir in HIV-infected patients. Since B*5701 prevalence varies among different populations, it is important to determine the carrier frequency prior to its use for the screening of HIV-infected patients.The aim of this study was to determine HLA-B*5701 carrier frequency in Chilean general population and HIV-infected patients referred for B*5701 typing. For that purpose 300 blood bank donors and 492 abacavir-naïve HIV-infected patients from Chile were screened for B*5701 by a sequence specific primer PCR.We detected 14/300 (4.7 percent) B*57-positive individuals in the Chilean general population, 11 (3.7 percent) were B*5701 positive, and 3 (1 percent) had another subtype.All were heterozygous,thus a B*5701 allele frequency of 2 percent was determined.Eleven of 492 (2.2 percent) HIV-patients carried a B*5701 allele. The difference between these frequencies is probably due to slow progression of HIV infection in HLA-B*5701 carriers, thus less patients would require antiretroviral therapy and B*5701 typing. Considering the usefulness of B*5701 screening, its prevalence in the Chilean general population,and the availability of a validated method,we conclude that HLA-B*5701 typing in Chilean HIV-infected patients about to initiate abacavir treatment is strongly recommended.