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Patients in sub-Saharan Africa generally have poor anticoagulation control. We review the potential reasons for this poor control, as well as the potential solutions. Challenges include the affordability and centralisation of anticoagulation care, problems with access to medicines and international normalised ratio monitoring, the lack of locally validated standardized dosing protocols, and low levels of anticoagulation knowledge among healthcare workers and patients. Increasing numbers of patients will need anticoagulation in the future because of the increasing burden of noncommunicable disease in the region. We propose that locally developed "warfarin care bundles" which address multiple anticoagulation challenges in combination may be the most appropriate solution in this setting currently.
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Anticoagulantes , Warfarina , África del Sur del Sahara/epidemiología , Coagulación Sanguínea , Humanos , Relación Normalizada Internacional , Warfarina/efectos adversosRESUMEN
Warfarin has existed for >7 decades and has been the anticoagulant of choice for many thromboembolic disorders. The recent introduction of direct-acting oral anticoagulants (DOACs) has, however, caused a shift in preference by healthcare professionals all over the world. DOACs have been found to be at least as effective as warfarin in prevention of stroke in patients with atrial fibrillation and in treatment of venous thromboembolism. In sub-Saharan Africa, however, the widespread use of DOACs has been hampered mainly by their higher acquisition costs. As the drugs come off patent, their use in sub-Saharan Africa is likely to increase. However, very few trials have been conducted in African settings, and safety concerns will need to be addressed with further study before widespread adoption into clinical practice.
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Fibrilación Atrial , Accidente Cerebrovascular , Administración Oral , África del Sur del Sahara/epidemiología , Anticoagulantes/efectos adversos , Fibrilación Atrial/complicaciones , Fibrilación Atrial/tratamiento farmacológico , Humanos , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/epidemiología , Accidente Cerebrovascular/prevención & control , Warfarina/efectos adversosRESUMEN
BACKGROUND: The high HIV prevalence in South Africa may potentially be shaping the local adverse drug reaction (ADR) burden. We aimed to describe the prevalence and characteristics of serious ADRs at admission, and during admission, to two South African children's hospitals. METHODS: We reviewed the folders of children admitted over sequential 30-day periods in 2015 to the medical wards and intensive care units of each hospital. We identified potential ADRs using a trigger tool developed for this study. A multidisciplinary team assessed ADR causality, type, seriousness, and preventability through consensus discussion. We used multivariate logistic regression to explore associations with serious ADRs. RESULTS: Among 1050 patients (median age 11 months, 56% male, 2.8% HIV-infected) with 1106 admissions we found 40 serious ADRs (3.8 per 100 drug-exposed admissions), including 9/40 (23%) preventable serious ADRs, and 8/40 (20%) fatal or near-fatal serious ADRs. Antibacterials, corticosteroids, psycholeptics, immunosuppressants, and antivirals were the most commonly implicated drug classes. Preterm neonates and children in middle childhood (6 to 11 years) were at increased risk of serious ADRs compared to infants (under 1 year) and term neonates: adjusted odds ratio (aOR) 5.97 (95% confidence interval 1.30 to 27.3) and aOR 3.63 (1.24 to 10.6) respectively. Other risk factors for serious ADRs were HIV infection (aOR 3.87 (1.14 to 13.2) versus HIV-negative) and increasing drug count (aOR 1.08 (1.04 to 1.12) per additional drug). CONCLUSIONS: Serious ADR prevalence in our survey was similar to the prevalence found elsewhere. In our setting, serious ADRs were associated with HIV-infection and the antiviral drug class was one of the most commonly implicated. Similar to other sub-Saharan African studies, a large proportion of serious ADRs were fatal or near-fatal. Many serious ADRs were preventable.
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Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Infecciones por VIH , Niño , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Hospitalización , Humanos , Lactante , Recién Nacido , Masculino , Estudios Prospectivos , Sudáfrica/epidemiologíaRESUMEN
AIMS: Fatal adverse drug reactions (ADRs) are important causes of death, but data from resource-limited settings are scarce. We determined the proportion of deaths in South African medical inpatients attributable to ADRs, and their preventability, stratified by human immunodeficiency virus (HIV) status. METHODS: We reviewed the folders of all patients who died over a 30 day period in the medical wards of four hospitals. We identified ADR-related deaths (deaths where an ADR was 'possible', 'probable' or 'certain' using WHO-UMC criteria and where the ADR contributed to death). We determined preventability according to previously published criteria. RESULTS: ADRs contributed to the death of 2.9% of medical admissions and 56 of 357 deaths (16%) were ADR-related. Tenofovir, rifampicin and co-trimoxazole were the most commonly implicated drugs. 43% of ADRs were considered preventable. The following factors were independently associated with ADR-related death: HIV-infected patients on antiretroviral therapy (adjusted odds ratio (aOR) 4.4, 95% confidence interval (CI) 1.6, 12), exposure to more than seven drugs (aOR 2.5, 95% CI 1.3, 4.8) and increasing comorbidity score (aOR 1.3, 95% CI 1.1, 1.7). CONCLUSIONS: In our setting, where HIV and tuberculosis are highly prevalent, fatal in-hospital ADRs were more common than reported in high income settings. Most deaths were attributed to drugs used in managing HIV and tuberculosis. A large proportion of the ADRs were preventable, highlighting the need to strengthen systems for health care worker training and support.
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Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/mortalidad , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/prevención & control , Hospitales/estadística & datos numéricos , Pacientes Internos/estadística & datos numéricos , Adulto , Anciano , Estudios Transversales , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Sudáfrica/epidemiología , Adulto JovenRESUMEN
AIMS: Prior research, largely focused on US male veterans, indicates an increased risk of cardiovascular disease among individuals with post-traumatic stress disorder (PTSD). Data from other settings and populations are scarce. The objective of this study is to examine PTSD as a risk factor for incident major adverse cardiovascular events (MACEs) in South Africa. METHODS: We analysed reimbursement claims (2011-2020) of a cohort of South African medical insurance scheme beneficiaries aged 18 years or older. We calculated adjusted hazard ratios (aHRs) for associations between PTSD and MACEs using Cox proportional hazard models and calculated the effect of PTSD on MACEs using longitudinal targeted maximum likelihood estimation. RESULTS: We followed 1,009,113 beneficiaries over a median of 3.0 years (IQR 1.1-6.0). During follow-up, 12,662 (1.3%) persons were diagnosed with PTSD and 39,255 (3.9%) had a MACE. After adjustment for sex, HIV status, age, population group, substance use disorders, psychotic disorders, major depressive disorder, sleep disorders and the use of antipsychotic medication, PTSD was associated with a 16% increase in the risk of MACEs (aHR 1.16, 95% confidence interval (CI) 1.05-1.28). The risk ratio for the effect of PTSD on MACEs decreased from 1.59 (95% CI 1.49-1.68) after 1 year of follow-up to 1.14 (95% CI 1.11-1.16) after 8 years of follow-up. CONCLUSION: Our study provides empirical support for an increased risk of MACEs in males and females with PTSD from a general population sample in South Africa. These findings highlight the importance of monitoring cardiovascular risk among individuals diagnosed with PTSD.
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Enfermedades Cardiovasculares , Trastorno Depresivo Mayor , Seguro , Trastornos por Estrés Postraumático , Femenino , Humanos , Masculino , Estudios de Cohortes , Trastornos por Estrés Postraumático/epidemiología , Trastornos por Estrés Postraumático/diagnóstico , Sudáfrica/epidemiología , Trastorno Depresivo Mayor/epidemiología , Factores de Riesgo , Enfermedades Cardiovasculares/epidemiologíaRESUMEN
Warfarin dose requirements are highly variable due to clinical and genetic factors. While genetic variants influencing warfarin dose have been identified in European and East Asian populations, more work is needed to identify African-specific genetic variants to help optimize warfarin dosing. We performed genome-wide association studies (GWAS) in four African cohorts from Uganda, South Africa, and Zimbabwe, totalling 989 warfarin-treated participants who reached stable dose and had international normalized ratios within therapeutic ranges. We also included two African American cohorts recruited by the International Warfarin Pharmacogenetics Consortium (n=316) and the University of Alabama at Birmingham (n=199). Following the GWAS, we performed standard error-weighted meta-analyses and then conducted stepwise conditional analyses to account for known loci (the CYP2C cluster SNP rs12777823 and CYP2C9 in chromosome 10; VKORC1 in chromosome 16). The genome-wide significance threshold was set at P<5×10-8. The meta-analysis, comprising 1,504 participants identified 242 significant SNPs across three genomic loci, with 99.6% of these located within known loci on chromosomes 10 (top SNP: rs58800757, P=4.27×10-13) and 16 (top SNP: rs9925964, P=9.97×10-16). Adjustment for the VKORC1 SNP -1639G>A revealed an additional locus on chromosome 2 (top SNPs rs116057875/rs115254730/rs115240773, P=3.64×10-8), implicating the MALL gene, that could indirectly influence warfarin response through interactions with caveolin-1. In conclusion, our meta-analysis of six cohorts of warfarin-treated patients of African ancestry reaffirmed the importance of CYP2C9 and VKORC1 in influencing warfarin dose requirements. We also identified a new locus (MALL), that still requires direct evidence of biological plausibility.
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BACKGROUND: The quality of warfarin anticoagulation among Sub-Saharan African patients is suboptimal. This is due to several factors, including a lack of standardized dosing algorithms, difficulty in providing timely international normalized ratio (INR) results, a lack of patient feedback on their experiences with treatment, a lack of education on adherence, and inadequate knowledge and training of health care workers. Low quality of warfarin anticoagulation, expressed as time in therapeutic range (TTR), is associated with higher adverse event rates, including bleeding and thrombosis, and ultimately, increased morbidity and mortality. Processes and interventions that improve this situation are urgently needed. OBJECTIVE: This study aims to evaluate the implementation of the "warfarin bundle," a package of interventions to improve the quality of anticoagulation and thereby clinical outcomes. The primary outcome for this study is TTR over the initial 3 months of warfarin therapy. METHODS: Patients aged 18 years or older who are newly initiated on warfarin for venous thromboembolism, atrial fibrillation, or valvular heart disease will be enrolled and followed up for 3 months at clinics in Cape Town, South Africa, and Kampala, Uganda, where the warfarin bundle is implemented. A retrospective review of the clinical records of patients on warfarin treatment before implementation (controls) will be used for comparison. This study uses a mixed methods approach of the implementation of patient- and process-centered activities to improve the quality of anticoagulation. Patient-centered activities include the use of clinical dosing algorithms, adherence support, and root cause analysis, whereas process-centered activities include point-of-care INR testing, staff training, and patient education and training. We will assess the impact of these interventions by comparing the TTR and safety outcomes across the 2 groups, as well as the cost-effectiveness and acceptability of the package. RESULTS: We started recruitment in June 2021 and stopped in August 2022, having recruited 167 participants. We obtained ethics approval from the University of Cape Town Faculty of Health Sciences Human Research Ethics Committee, the Provincial Health Research Committees in South Africa, the Joint Clinical Research Centre Institutional Review Board, Kampala, and the University of Liverpool Research Ethics Committee. As of February 2023, data cleaning and formal analysis are underway. We expect to publish the full results by December 2023. CONCLUSIONS: We anticipate that the "bundle of care," which includes a clinical algorithm to guide individualized dosing of warfarin, will improve INR control and TTR of patients in Uganda and South Africa. We will use these findings to design a larger, multisite clinical trial across several Sub-Saharan African countries. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/46710.
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AIMS: The coronavirus disease 2019 (COVID-19) pandemic and ensuing restrictions have negatively affected the mental health and well-being of the general population, and there is increasing evidence suggesting that lockdowns have led to a disruption of health services. In March 2020, South Africa introduced a lockdown in response to the COVID-19 pandemic, entailing the suspension of all non-essential activities and a complete ban of tobacco and alcohol sales. We studied the effect of the lockdown on mental health care utilisation rates in private-sector care in South Africa. METHODS: We conducted an interrupted time-series analysis using insurance claims from 1 January 2017 to 1 June 2020 of beneficiaries 18 years or older from a large private sector medical insurance scheme. We calculated weekly outpatient consultation and hospital admission rates for organic mental disorders, substance use disorders, serious mental disorders, depression, anxiety, other mental disorders, any mental disorder and alcohol withdrawal syndrome. We calculated adjusted odds ratios (OR) for the effect of the lockdown on weekly outpatient consultation and hospital admission rates and the weekly change in rates during the lockdown until 1 June 2020. RESULTS: 710 367 persons were followed up for a median of 153 weeks. Hospital admission rates (OR 0.38; 95% confidence interval (CI) 0.33-0.44) and outpatient consultation rates (OR 0.74; 95% CI 0.63-0.87) for any mental disorder decreased substantially after the introduction of the lockdown and did not recover to pre-lockdown levels by 1 June 2020. Health care utilisation rates for alcohol withdrawal syndrome doubled after the introduction of the lockdown, but the statistical uncertainty around the estimates was large (OR 2.24; 95% CI 0.69-7.24). CONCLUSIONS: Mental health care utilisation rates for inpatient and outpatient services decreased substantially after the introduction of the lockdown. Hospital admissions and outpatient consultations for alcohol withdrawal syndrome increased after the introduction of the lockdown, but statistical uncertainty precludes strong conclusions about a potential unintended effect of the alcohol sales ban. Governments should integrate strategies for ensuring access and continuity of essential mental health services during lockdowns in pandemic preparedness planning.
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Alcoholismo , COVID-19 , Síndrome de Abstinencia a Sustancias , Alcoholismo/epidemiología , Control de Enfermedades Transmisibles , Humanos , Salud Mental , Pandemias , Sudáfrica/epidemiología , Síndrome de Abstinencia a Sustancias/epidemiologíaRESUMEN
Warfarin remains the most widely prescribed oral anticoagulant in sub-Saharan Africa. However, because of its narrow therapeutic index, dosing can be challenging. We have therefore (a) evaluated and compared the performance of 21 machine-learning techniques in predicting stable warfarin dose in sub-Saharan Black-African patients and (b) externally validated a previously developed Warfarin Anticoagulation in Patients in Sub-Saharan Africa (War-PATH) clinical dose-initiation algorithm. The development cohort included 364 patients recruited from eight outpatient clinics and hospital departments in Uganda and South Africa (June 2018-July 2019). Validation was conducted using an external validation cohort (270 patients recruited from August 2019 to March 2020 in 12 outpatient clinics and hospital departments). Based on the mean absolute error (MAE; mean of absolute differences between the actual and predicted doses), random forest regression (12.07 mg/week; 95% confidence interval [CI], 10.39-13.76) was the best performing machine-learning technique in the external validation cohort, whereas the worst performing technique was model trees (17.59 mg/week; 95% CI, 15.75-19.43). By comparison, the simple, commonly used regression technique (ordinary least squares) performed similarly to more complex supervised machine-learning techniques and achieved an MAE of 13.01 mg/week (95% CI, 11.45-14.58). In summary, we have demonstrated that simpler regression techniques perform similarly to more complex supervised machine-learning techniques. We have also externally validated our previously developed clinical dose-initiation algorithm, which is being prospectively tested for clinical utility.
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Anticoagulantes/administración & dosificación , Aprendizaje Automático , Warfarina/administración & dosificación , Adulto , África del Sur del Sahara , Factores de Edad , Algoritmos , Peso Corporal , Cálculo de Dosificación de Drogas , Femenino , Infecciones por VIH/epidemiología , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Modelos Biológicos , Reproducibilidad de los Resultados , Factores Sexuales , Simvastatina/administración & dosificaciónRESUMEN
Diversity in pharmacogenomic studies is poor, especially in relation to the inclusion of black African patients. Lack of funding and difficulties in recruitment, together with the requirement for large sample sizes because of the extensive genetic diversity in Africa, are amongst the factors which have hampered pharmacogenomic studies in Africa. Warfarin is widely used in sub-Saharan Africa, but as in other populations, dosing is highly variable due to genetic and non-genetic factors. In order to identify genetic factors determining warfarin response variability, we have conducted a genome-wide association study (GWAS) of plasma concentrations of warfarin enantiomers/metabolites in sub-Saharan black-Africans. This overcomes the issue of non-adherence and may have greater sensitivity at genome-wide level, to identify pharmacokinetic gene variants than focusing on mean weekly dose, the usual end-point used in previous studies. Participants recruited at 12 outpatient sites in Uganda and South Africa on stable warfarin dose were genotyped using the Illumina Infinium H3Africa Consortium Array v2. Imputation was conducted using the 1,000 Genomes Project phase III reference panel. Warfarin/metabolite plasma concentrations were determined by high-performance liquid chromatography with tandem mass spectrometry. Multivariable linear regression was undertaken, with adjustment made for five non-genetic covariates and ten principal components of genetic ancestry. After quality control procedures, 548 participants and 17,268,054 SNPs were retained. CYP2C9*8, CYP2C9*9, CYP2C9*11, and the CYP2C cluster SNP rs12777823 passed the Bonferroni-adjusted replication significance threshold (p < 3.21E-04) for warfarin/metabolite ratios. In an exploratory GWAS analysis, 373 unique SNPs in 13 genes, including CYP2C9*8, passed the Bonferroni-adjusted genome-wide significance threshold (p < 3.846E-9), with 325 (87%, all located on chromosome 10) SNPs being associated with the S-warfarin/R-warfarin outcome (top SNP rs11188082, CYP2C19 intron variant, p = 1.55E-17). Approximately 69% of these SNPs were in linkage disequilibrium (r 2 > 0.8) with CYP2C9*8 (n = 216) and rs12777823 (n = 8). Using a pharmacokinetic approach, we have shown that variants other than CYP2C9*2 and CYP2C9*3 are more important in sub-Saharan black-Africans, mainly due to the allele frequencies. In exploratory work, we conducted the first warfarin pharmacokinetics-related GWAS in sub-Saharan Africans and identified novel SNPs that will require external replication and functional characterization before they can be considered for inclusion in warfarin dosing algorithms.
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We aimed to summarize and describe the burden of serious adverse drug reactions (ADRs) in sub-Saharan Africa (SSA) in the era of antiretroviral therapy. We searched Medline, CINAHL, Africa-Wide Information, Scopus, and Web of Science, without language restriction up to March 2021. We hand-searched reference lists, conference abstracts, and dissertation databases. We included studies reporting proportions of admissions attributed to ADRs, admissions prolonged by ADRs, or in-hospital deaths attributed to ADRs. Two reviewers independently screened the studies, reviewed the study quality using a previously published tool, and extracted the data. We tested for heterogeneity using I2 -statistics and summarized the study results using medians and interquartile ranges. Subgroup analyses summarized the results by study quality, setting, methodology, and population. From 1005 unique references identified, we included 15 studies. Median study quality was 7/10; heterogeneity was very high. Median [IQR] proportion of admissions attributed to ADRs was 4.8% [1.5% to 7.0%] (14 studies) and 6.4% [4.0% to 8.4%] in nine active surveillance studies in adults. Two pediatric studies reported the proportion of admissions prolonged by ADRs (0.29% and 0.99%). Three studies reported the proportion of in-hospital deaths attributed to ADRs (2.5%, 13%, and 16%). Antiretroviral and antituberculosis drugs were often implicated in serious ADRs. Evidence of the burden of serious ADRs in SSA is patchy and heterogeneous. A few high-quality studies suggest that the burden is considerable, and that it reflects the regional impact of the HIV pandemic. Further characterization of this burden is required, ideally in studies of standardized methodology.
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Antirretrovirales/efectos adversos , Antituberculosos/efectos adversos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Adulto , África del Sur del Sahara , Antirretrovirales/administración & dosificación , Antituberculosos/administración & dosificación , Niño , Costo de Enfermedad , Hospitalización/estadística & datos numéricos , HumanosRESUMEN
INTRODUCTION: South Africa has the world's largest antiretroviral treatment programme, which may contribute to the adverse drug reaction (ADR) burden. We aimed to determine the proportion of adult non-trauma emergency unit (EU) presentations attributable to ADRs and to characterise ADR-related EU presentations, stratified according to HIV status, to determine the contribution of drugs used in management of HIV and its complications to ADR-related EU presentations, and identify factors associated with ADR-related EU presentation. METHODS: We conducted a retrospective folder review on a random 1.7% sample of presentations over a 12-month period in 2014/2015 to the EUs of two hospitals in Cape Town, South Africa. We identified potential ADRs with the help of a trigger tool. A multidisciplinary panel assessed potential ADRs for causality, severity, and preventability. RESULTS: We included 1010 EU presentations and assessed 80/1010 (7.9%) as ADR-related, including 20/239 (8.4%) presentations among HIV-positive attendees. Among HIV-positive EU attendees with ADRs 17/20 (85%) were admitted, versus 22/60 (37%) of HIV-negative/unknown EU attendees. Only 5/21 (24%) ADRs in HIV-positive EU attendees were preventable, versus 24/63 (38%) in HIV-negative/unknown EU attendees. On multivariate analysis, only increasing drug count was associated with ADR-related EU presentation (adjusted odds ratio 1.10 per additional drug, 95% confidence interval 1.03 to 1.18), adjusted for age, sex, HIV status, comorbidity, and hospital. CONCLUSIONS: ADRs caused a significant proportion of EU presentations, similar to findings from other resource-limited settings. The spectrum of ADR manifestations in our EUs reflects South Africa's colliding epidemics of infectious and non-communicable diseases. ADRs among HIV-positive EU attendees were more severe and less likely to be preventable.
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Warfarin remains the oral anticoagulant of choice in sub-Saharan Africa. However, dosing is challenging due to a highly variable clinical response for a given dose. This study aimed to develop and validate a clinical warfarin dose-initiation model in sub-Saharan Black-African patients. For the development cohort, we used data from 364 patients who were recruited from 8 outpatient clinics and hospital departments in Uganda and South Africa (June 2018-July 2019). Validation was undertaken using the International Warfarin Pharmacogenetics Consortium (IWPC) dataset (690 black patients). Four predictors (age, weight, target International Normalized Ratio range, and HIV status) were included in the final model, which achieved mean absolute errors (MAEs; mean of absolute differences between true dose and dose predicted by the model) of 11.6 (95% confidence interval (CI) 10.4-12.8) and 12.5 (95% CI 11.6-13.4) mg/week in the development and validation cohorts, respectively. Two other clinical models, IWPC and Gage, respectively, obtained MAEs of 12.5 (95% CI 11.3-13.7) and 12.7 (95% CI 11.5-13.8) mg/week in the development cohort, and 12.1 (95% CI 11.2-13.0) and 12.2 (95% CI 11.4-13.1) mg/week in the validation cohort. Compared with fixed dose-initiation, our model decreased the percentage of patients at high risk of suboptimal anticoagulation by 7.5% (1.5-13.7%) and 11.9% (7.1-16.8%) in the development and validation cohorts, respectively. The clinical utility of this model will be tested in a prospective study. Study Highlights WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC? â Warfarin dosing remains challenging due to a highly variable clinical response for a given dose. WHAT QUESTION DID THIS STUDY ADDRESS? â Can a clinical dose-initiation model be developed and validated for sub-Saharan Black-African patients? WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE? â We have developed the first warfarin dose-initiation clinical model for Black-African patients in Uganda and South Africa. HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE? â We will be implementing and validating this model in a prospective cohort to inform future large-scale implementation. More optimized dosing should improve the quality of warfarin anticoagulation in these two developing countries.
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Población Negra , Warfarina/administración & dosificación , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Peso Corporal , Niño , Estudios de Cohortes , Relación Dosis-Respuesta a Droga , Femenino , Seropositividad para VIH , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sudáfrica , Resultado del Tratamiento , Uganda , Warfarina/efectos adversos , Warfarina/uso terapéutico , Adulto JovenRESUMEN
INTRODUCTION: Warfarin is the most commonly prescribed oral anticoagulant in sub-Saharan Africa and requires ongoing monitoring. The burden of both infectious diseases and non-communicable diseases is high and medicines used to treat comorbidities may interact with warfarin. We describe service provision, patient characteristics, and anticoagulation control at selected anticoagulation clinics in Uganda and South Africa. METHODS: We evaluated two outpatient anticoagulation services in Kampala, Uganda and three in Cape Town, South Africa between 1 January and 31 July 2018. We collected information from key staff members about the clinics' service provision and extracted demographic and clinical data from a sample of patients' clinic records. We calculated time in therapeutic range (TTR) over the most recent 3-month period using the Rosendaal interpolation method. RESULTS: We included three tertiary level, one secondary level and one primary level anticoagulation service, seeing between 30 and 800 patients per month. Care was rendered by nurses, medical officers, and specialists. All healthcare facilities had on-site pharmacies; laboratory INR testing was off-site at two. Three clinics used warfarin dose-adjustment protocols; these were not validated for local use. We reviewed 229 patient clinical records. Most common indications for warfarin were venous thrombo-embolism in 112/229 (49%), atrial fibrillation in 74/229 (32%) and valvular heart disease in 30/229 (13%). Patients were generally followed up monthly. HIV prevalence was 20% and 5% at Ugandan and South African clinics respectively. Cardiovascular comorbidity predominated. Furosemide, paracetamol, enalapril, simvastatin, and tramadol were the most common concomitant drugs. Anticoagulation control was poor at all included clinics with median TTR of 41% (interquartile range 14% to 69%). CONCLUSIONS: TTR was suboptimal at all included sites, despite frequent patient follow-up. Strategies to improve INR control in sub-Saharan patients taking warfarin are needed. Locally validated warfarin dosing algorithms in Uganda and South Africa may improve INR control.
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Anticoagulantes/uso terapéutico , Fibrilación Atrial/tratamiento farmacológico , Enfermedades de las Válvulas Cardíacas/tratamiento farmacológico , Tromboembolia Venosa/tratamiento farmacológico , Warfarina/uso terapéutico , Adulto , Anciano , Atención Ambulatoria , Fibrilación Atrial/complicaciones , Estudios Transversales , Monitoreo de Drogas , Femenino , Infecciones por VIH/complicaciones , Infecciones por VIH/epidemiología , Infecciones por VIH/patología , Enfermedades de las Válvulas Cardíacas/complicaciones , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Centros de Atención Secundaria , Sudáfrica/epidemiología , Centros de Atención Terciaria , Uganda/epidemiología , Tromboembolia Venosa/complicacionesRESUMEN
INTRODUCTION: A new method to assess causality of suspected adverse drug reactions, the Liverpool Adverse Drug Reaction Causality Assessment Tool (LCAT), showed high interrater agreement when used by its developers. Our aim was to compare the interrater agreement achieved by LCAT to that achieved by another causality assessment method, the World Health Organization-Uppsala Monitoring Centre system for standardised case causality assessment (WHO-UMC system), in our setting. METHODS: Four raters independently assessed adverse drug reaction causality of 48 drug-event pairs, identified during a hospital-based survey. A randomised design ensured that no washout period was required between assessments with the two methods. We compared the methods' interrater agreement by calculating agreement proportions, kappa statistics, and the intraclass correlation coefficient. We identified potentially problematic questions in the LCAT by comparing raters' responses to individual questions. RESULTS: Overall unweighted kappa was 0.61 (95% CI 0.43 to 0.80) on the WHO-UMC system and 0.27 (95% CI 0.074 to 0.46) on the LCAT. Pairwise unweighted Cohen kappa ranged from 0.33 to 1.0 on the WHO-UMC system and from 0.094 to 0.71 on the LCAT. The intraclass correlation coefficient was 0.86 (95% CI 0.74 to 0.92) on the WHO-UMC system and 0.61 (95% CI 0.39 to 0.77) on the LCAT. Two LCAT questions were identified as significant points of disagreement. DISCUSSION: We were unable to replicate the high interrater agreement achieved by the LCAT developers and instead found its interrater agreement to be lower than that achieved when using the WHO-UMC system. We identified potential reasons for this and recommend priority areas for improving the LCAT.
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Sistemas de Registro de Reacción Adversa a Medicamentos/estadística & datos numéricos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Adulto , Algoritmos , Fármacos Anti-VIH/efectos adversos , Antituberculosos/efectos adversos , Femenino , Hospitales , Humanos , Hipoglucemiantes/efectos adversos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Admisión del Paciente , Distribución Aleatoria , Reproducibilidad de los Resultados , Sudáfrica , Encuestas y Cuestionarios , Vasodilatadores/efectos adversos , Organización Mundial de la SaludRESUMEN
INTRODUCTION: WHO recommends tenofovir, efavirenz, and lamivudine or emtricitabine for first-line antiretroviral therapy (ART) in adults, which replaced more toxic regimens using stavudine, zidovudine or nevirapine. Areas covered: We searched Pubmed to identify observational studies and randomized controlled trials reporting toxicity of these antiretrovirals published between 2011 and 2016, and hand-searched abstracts presented at major HIV conferences in 2015 and 2016, focusing on data from sub-Saharan Africa. Tenofovir's nephrotoxicity manifests as mild renal tubular dysfunction (common and of uncertain clinical significance), acute kidney injury (rare), and chronic declining glomerular filtration rate (common). African studies, which include high proportions of patients with renal dysfunction from opportunistic diseases, report population improvement in renal function after starting tenofovir-based ART. Tenofovir modestly decreases bone mineral density, and there is emerging data that this increases fracture risk. Efavirenz commonly causes early self-limiting neuropsychiatric toxicity and hypersensitivity rashes. Recent studies have highlighted its long-term neuropsychiatric effects, notably suicidality and neurocognitive impairment, and metabolic toxicities (dyslipidemia, dysglycemia, and lipoatrophy). We point out the challenges clinicians face in the recognition and attribution of adverse drug reactions. Expert commentary: Tenofovir and efavirenz are generally well tolerated, but both are associated with potentially serious toxicities. Pharmacovigilance systems in resource-limited settings with high HIV burden should be strengthened.
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Fármacos Anti-VIH/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Adulto , Alquinos , Fármacos Anti-VIH/efectos adversos , Benzoxazinas/administración & dosificación , Benzoxazinas/efectos adversos , Ciclopropanos , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Tenofovir/administración & dosificación , Tenofovir/efectos adversos , Organización Mundial de la SaludRESUMEN
INTRODUCTION: The National HIV & Tuberculosis Health Care Worker (HCW) Hotline provides advice on the management of suspected adverse drug reactions (ADRs). We describe suspected ADRs reported to the hotline by HCWs, concordance with advice, and patient outcomes. METHODS: We reviewed suspected ADRs in HIV-infected patients, patients taking antiretrovirals and patients taking anti-tuberculosis therapy reported from May 2013 to October 2014. We performed causality assessment using the World Health Organization Uppsala Monitoring Centre (WHO-UMC) criteria. We included suspected ADRs categorized as certain, probable or possible in further analysis. RESULTS: We received 772 ADR reports, of which 87/772 (11.3%) were classified as certain, 176/772 (22.8%) as probable, 361/772 (46.8%) as possible, and 148/772 (19.2%) as unlikely or unassessable. The most frequent ADRs were rash, drug-induced liver injury (DILI) and kidney injury, comprising 110/624 (17.6%), 87/624 (13.9%), and 77/624 (12.3%), respectively. The ADR was severe in 27.3% of rashes, 36.4% of kidney injury reports and 88.5% of DILI reports. Most frequently implicated drugs, either alone or in combination with other potentially causative drugs, were efavirenz (rashes), efavirenz and anti-tuberculosis drugs (DILI) and tenofovir (kidney injury). In 383 cases with HCW follow-up, 254 (66.3%) improved, 9 (2.3%) had complete resolution, 32 (8.4%) remained unchanged, 6 (1.6%) deteriorated, 10 (2.6%) died and 72 (18.8%) had unknown outcome. Advice provided was followed in 93.2% of these cases. Of 223 ADRs with preventability data, 40 (17.9%) were preventable. CONCLUSION: Queries about rashes, DILIs and kidney injuries were common. Detection and management of these ADRs should be included in HCW training. In cases with follow-up, concordance with advice was high, and HCWs reported improvement in the majority.
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Lesión Renal Aguda/epidemiología , Sistemas de Registro de Reacción Adversa a Medicamentos/estadística & datos numéricos , Fármacos Anti-VIH/efectos adversos , Antituberculosos/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/epidemiología , Lesión Renal Aguda/etiología , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/uso terapéutico , Antituberculosos/administración & dosificación , Antituberculosos/uso terapéutico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/etiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/epidemiología , Humanos , Estudios Prospectivos , Tuberculosis/tratamiento farmacológico , Tuberculosis/epidemiologíaRESUMEN
Limited data exist on the burden of serious adverse drug reactions (ADRs) in sub-Saharan Africa, which has high HIV and tuberculosis prevalence. We determined the proportion of adult admissions attributable to ADRs at 4 hospitals in South Africa. We characterized drugs implicated in, risk factors for, and the preventability of ADR-related admissions.We prospectively followed patients admitted to 4 hospitals' medical wards over sequential 30-day periods in 2013 and identified suspected ADRs with the aid of a trigger tool. A multidisciplinary team performed causality, preventability, and severity assessment using published criteria. We categorized an admission as ADR-related if the ADR was the primary reason for admission.There were 1951 admissions involving 1904 patients: median age was 50 years (interquartile range 34-65), 1057 of 1904 (56%) were female, 559 of 1904 (29%) were HIV-infected, and 183 of 1904 (10%) were on antituberculosis therapy (ATT). There were 164 of 1951 (8.4%) ADR-related admissions. After adjustment for age and ATT, ADR-related admission was independently associated (Pâ≤â0.02) with female sex (adjusted odds ratio [aOR] 1.51, 95% confidence interval [95% CI] 1.06-2.14), increasing drug count (aOR 1.14 per additional drug, 95% CI 1.09-1.20), increasing comorbidity score (aOR 1.23 per additional point, 95% CI 1.07-1.41), and use of antiretroviral therapy (ART) if HIV-infected (aOR 1.92 compared with HIV-negative/unknown, 95% CI 1.17-3.14). The most common ADRs were renal impairment, hypoglycemia, liver injury, and hemorrhage. Tenofovir disoproxil fumarate, insulin, rifampicin, and warfarin were most commonly implicated, respectively, in these 4 ADRs. ART, ATT, and/or co-trimoxazole were implicated in 56 of 164 (34%) ADR-related admissions. Seventy-three of 164 (45%) ADRs were assessed as preventable.In our survey, approximately 1 in 12 admissions was because of an ADR. The range of ADRs and implicated drugs reflect South Africa's high HIV and tuberculosis burden. Identification and management of these ADRs should be considered in HIV and tuberculosis care and treatment programs and should be emphasized in health care worker training programmes.