Ushma Mehta
University of Cape Town
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Publication
Featured researches published by Ushma Mehta.
Lancet Infectious Diseases | 2007
Ushma Mehta; Gary Maartens
The non-nucleoside reverse transcriptase inhibitors (NNRTIs) efavirenz and nevirapine are chemically distinct, but both may cause cutaneous hypersensitivity and hepatotoxicity. We reviewed the literature to assess the evidence for cross-reactivity between nevirapine and efavirenz. All papers, abstracts, or presentations, regardless of study design, that made reference to the response of patients who were switched from one NNRTI to another as a result of an adverse drug reaction were included. Most of the studies were retrospective. Recurrent reactions occurred in 30 (12.6%) of 239 reported patients with rash who were switched from nevirapine to efavirenz, compared with eight (50%) of 16 patients switched from efavirenz to nevirapine. Hepatitis did not recur in either the 11 reported patients switched from nevirapine to efavirenz, or in the single reported patient who was switched from efavirenz to nevirapine. Substituting efavirenz for nevirapine following hepatotoxicity or cutaneous hypersensitivity appears to be reasonable, providing that the adverse reaction to nevirapine was not life-threatening. There is insufficient evidence to recommend substituting nevirapine for efavirenz following either hepatotoxicity or cutaneous hypersensitivity.
Drug Safety | 2008
Esperança Sevene; Alda Mariano; Ushma Mehta; Maria Jose Pires Machai; Alexander Dodoo; David Vilardell; Sam Patel; Karen I. Barnes; Xavier Carné
AbstractBackground: The roll out of various public health programmes involving mass administration of medicines calls for the deployment of responsive pharmacovigilance systems to permit identification of signals of rare or even common adverse reactions. In developing countries in Africa, these systems are mostly absent and their performance under any circumstance is difficult to predict given the known shortage of human, financial and technical resources. Nevertheless, the importance of such systems in all countries is not in doubt, and research to identify problems, with the aim of offering pragmatic solutions, is urgently needed. Objective: To examine the impact of training and monitoring of healthcare workers, making supervisory visits and the availability of telecommunication and transport facilities on the implementation of a pharmacovigilance system in Mozambique. Methods: This was a descriptive study enumerating the lessons learnt and challenges faced in implementing a spontaneous reporting system in two rural districts of Mozambique — Namaacha and Matutuine — where remote location, poor telecommunication services and a low level of education of health professionals are ongoing challenges. A ’yellow card’ system for spontaneous reporting of adverse drug reactions (ADRs) was instituted following training of health workers in the selected districts. Thirty-five health professionals (3 medical doctors, 2 technicians, 24 nurses, 4 basic healthcare agents and 2 pharmacy agents) in these districts were trained to diagnose, treat and report ADRs to all medicines using a standardized yellow card system. There were routine site visits to identify and clarify any problems in filling in and sending the forms. One focal person was identified in each district to facilitate communication between the health professionals and the National Pharmacovigilance Unit (NPU). The report form was assessed for quality and causality. The availability of telecommunications and transport was assessed. Results: Fourteen months after the first training, 67 ADR reports involving 74 adverse events were received by the NPU involving 25 separate drugs, 16 of which were causally (certainly, probably or possibly) linked to the reaction. Most reported ADRs were dermatological reactions (83.1%). Antimalarial drugs (chloroquine, amodiaquine, quinine, artesunate and sulfadoxine/pyrimethamine) were mentioned in 33 (50.8%) of the reports. There were 14 reactions classified as serious and no fatal reactions were reported. There were differences in telecommunications and transport facilities between the districts that might have contributed to the different number of reports. Conclusion: Health professionals of all levels of education (including basic training) from rural areas could contribute to ADR spontaneous reporting systems. Training, quality-assurance visits and the ongoing presence of focal persons can promote reporting and improve the quality of reports submitted.
Tropical Medicine & International Health | 2007
Ushma Mehta; David N. Durrheim; Lucille Blumberg; S. Donohue; F. Hansford; Aaron Mabuza; Philip Kruger; J. K. Gumede; E. Immelman; A. Sánchez Canal; J. J. Hugo; G. Swart; Karen I. Barnes
Objectives To identify case management, health system and antimalarial drug factors contributing to malaria deaths.
Drug Safety | 2007
Ushma Mehta; David N. Durrheim; Aaron Mabuza; Lucille Blumberg; Elizabeth Allen; Karen I. Barnes
Abstractp ]Background and objectives: Prior to the introduction of artemisinin-based combination antimalarial therapy in Mpumalanga province, South Africa, a pharmacovigilance strategy was developed to pilot locally relevant surveillance methods for detecting serious adverse drug reactions (ADRs) and signals related to artesunate plus sulfadoxine/pyrimethamine. Study design: From 1 March 2002 to 30 June 2004, five methods for detecting ADRs in patients receiving antimalarials were piloted in the rural communities of Mpumalanga province in South Africa: (i) home follow-up of patients by malaria control staff; (ii) enhanced spontaneous reporting of suspected ADRs by health professionals at clinics and hospitals; (iii) active hospital surveillance for malaria-related admissions and patients recently treated for malaria; (iv) a confidential enquiry into malaria-related deaths; and (v) adverse events monitoring during two therapeutic efficacy studies conducted in 2002 and 2004. Results: During the study period, the malaria control programme was notified of 4778 cases of malaria while sulfadoxine/pyrimethamine monotherapy was the recommended treatment and 7692 cases after the introduction of artesunate plus sulfadoxine/pyrimethamine in January 2003. Of 2393 home follow-up visits of reported cases of malaria, three fatal adverse events were identified where recent use of artesunate plus sulfadoxine/pyrimethamine treatment was reported. Two cases were attributed to poor response to treatment, while one case was considered possibly related to artesunate plus sulfadoxine/pyrimethamine treatment. Clinic and hospital surveillance reported six ADRs in association with sulfadoxine/pyrimethamine treatment, five being treatment failures and one being a non-serious rash. During active hospital surveillance, 38 inpatients exposed to sulfadoxine/pyrimethamine were identified, including one child who experienced pancytopenia following treatment with sulfadoxine/pyrimethamine 11 days before admission; this adverse effect was considered to be possibly due to sulfadoxine/pyrimethamine treatment. The confidential enquiry into malaria- 900 related deaths identified three adverse events, including a death where the contribution of treatment could not be excluded. A therapeutic efficacy study of 95 patients followed over 42 days identified one case of repeated vomiting possibly associated with artesunate plus sulfadoxine/pyrimethamine. Conclusion: Multifaceted monitoring throughout the malaria patient journey is necessary in developing countries implementing new treatments to safeguard against missing serious complications associated with malaria treatment.
BMC Pregnancy and Childbirth | 2012
Ushma Mehta; Christine Clerk; Elizabeth Allen; Mackensie Yore; Esperança Sevene; Jan Singlovic; Max Petzold; Viviana Mangiaterra; Elizabeth Elefant; Frank M. Sullivan; Lewis B. Holmes; Melba Gomes
BackgroundThe absence of robust evidence of safety of medicines in pregnancy, particularly those for major diseases provided by public health programmes in developing countries, has resulted in cautious recommendations on their use. We describe a protocol for a Pregnancy Registry adapted to resource-limited settings aimed at providing evidence on the safety of medicines in pregnancy.Methods/DesignSentinel health facilities are chosen where women come for prenatal care and are likely to come for delivery. Staff capacity is improved to provide better care during the pregnancy, to identify visible birth defects at delivery and refer infants with major anomalies for surgical or clinical evaluation and treatment. Consenting women are enrolled at their first antenatal visit and careful medical, obstetric and drug-exposure histories taken; medical record linkage is encouraged. Enrolled women are followed up prospectively and their histories are updated at each subsequent visit. The enrolled woman is encouraged to deliver at the facility, where she and her baby can be assessed.DiscussionIn addition to data pooling into a common WHO database, the WHO Pregnancy Registry has three important features: First is the inclusion of pregnant women coming for antenatal care, enabling comparison of birth outcomes of women who have been exposed to a medicine with those who have not. Second is its applicability to resource-poor settings regardless of drug or disease. Third is improvement of reproductive health care during pregnancies and at delivery. Facility delivery enables better health outcomes, timely evaluation and management of the newborn, and the collection of reliable clinical data. The Registry aims to improve maternal and neonatal care and also provide much needed information on the safety of medicines in pregnancy.
Medicine | 2016
Johannes P. Mouton; Christine Njuguna; Nicole Kramer; Annemie Stewart; Ushma Mehta; Marc Blockman; Melony Fortuin-de Smidt; Reneé de Waal; Andy Parrish; Douglas Wilson; Ehimario U. Igumbor; Getahun Aynalem; Mukesh Dheda; Gary Maartens; Karen Cohen
AbstractLimited 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 (P ⩽ 0.02) 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 Africas 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.
South African Medical Journal | 2013
Ushma Mehta; Mukesh Dheda; Gavin Steel; Marc Blockman; Augustin Ntilivamunda; Gary Maartens; Yogan Pillay; Karen Cohen
This report outlines findings and recommendations of a national pharmacovigilance workshop held in August 2012 in South Africa (SA). A survey of current pharmacovigilance activities, conducted in preparation for the meeting, identified multiple programmes collecting drug safety data in SA, with limited co-ordination at national level. The meeting resolved that existing pharmacovigilance programmes need to be strengthened and consolidated to ensure that important local safety issues are addressed, data can be pooled and compared and outputs shared more widely. Pharmacovigilance activities should inform treatment guidelines with the goal of improving patient care. A variety of pharmaco-epidemiological approaches should be employed, including nesting drug safety studies within existing sentinel cohorts and the creation of a pregnancy exposure registry. The attendees agreed on key principles that will inform a national pharmacovigilance plan and compiled a list of priority pharmacovigilance issues facing public health programmes in SA.
BMC Medical Research Methodology | 2013
Elizabeth Allen; Adiel K Mushi; Isolide S Massawe; Lasse S. Vestergaard; Martha M. Lemnge; Sarah G. Staedke; Ushma Mehta; Karen I. Barnes; Clare Chandler
BackgroundAccurately characterizing a drug’s safety profile is essential. Trial harm and tolerability assessments rely, in part, on participants’ reports of medical histories, adverse events (AEs), and concomitant medications. Optimal methods for questioning participants are unclear, but different methods giving different results can undermine meta-analyses. This study compared methods for eliciting such data and explored reasons for dissimilar participant responses.MethodsParticipants from open-label antimalarial and antiretroviral interaction trials in two distinct sites (South Africa, n = 18 [all HIV positive]; Tanzania, n = 80 [86% HIV positive]) were asked about ill health and treatment use by sequential use of (1) general enquiries without reference to particular conditions, body systems or treatments, (2) checklists of potential health issues and treatments, (3) in-depth interviews. Participants’ experiences of illness and treatment and their reporting behaviour were explored qualitatively, as were trial clinicians’ experiences with obtaining participant reports. Outcomes were the number and nature of data by questioning method, themes from qualitative analyses and a theoretical interpretation of participants’ experiences.ResultsThere was an overall cumulative increase in the number of reports from general enquiry through checklists to in-depth interview; in South Africa, an additional 12 medical histories, 21 AEs and 27 medications; in Tanzania an additional 260 medical histories, 1 AE and 11 medications. Checklists and interviews facilitated recognition of health issues and treatments, and consideration of what to report. Information was sometimes not reported because participants forgot, it was considered irrelevant or insignificant, or they feared reporting. Some medicine names were not known and answers to questions were considered inferior to blood tests for detecting ill health. South African inpatient volunteers exhibited a “trial citizenship”, working to achieve researchers’ goals, while Tanzanian outpatients sometimes deferred responsibility for identifying items to report to trial clinicians.ConclusionsQuestioning methods and trial contexts influence the detection of adverse events, medical histories and concomitant medications. There should be further methodological work to investigate these influences and find appropriate questioning methods.
PLOS ONE | 2017
Johannes P. Mouton; Ushma Mehta; Dawn P. Rossiter; Gary Maartens; Karen Cohen
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.
Malaria Journal | 2013
Elizabeth Allen; Clare Chandler; Nyaradzo Mandimika; Cheryl Pace; Ushma Mehta; Karen I. Barnes
BackgroundParticipant reports of medical histories, adverse events (AE) and non-study drugs are integral to evaluating harm in clinical research. However, interpreting or synthesizing results is complicated if studies use different methods for ascertaining and assessing these data. To explore how these data are obtained in malaria drug studies, a descriptive online survey of clinical researchers was conducted during 2012 and 2013.MethodsThe survey was advertised through e-mails, collaborators and at conferences. Questions aimed to capture the detail, rationale and application of methods used to obtain relevant data within various study designs and populations. Closed responses were analysed using proportions, open responses through identifying repeating ideas and underlying concepts.ResultsOf fifty-two respondents from 25 counties, 87% worked at an investigational site and 75% reported about an interventional study. Studies employed a range of methods to elicit, assess and record participant-reported AEs and related data. Questioning about AEs in 31% of interventional studies was a combination of general (open questions about health) and structured (reference to specific health-related items), 26% used structured only and 18% general only. No observational studies used general questioning alone. A minority incorporated pictorial tools. Rationales for the questioning approach included: standardization of assessment or data capture, specificity or comprehensiveness of data sought, avoidance of suggestion, feasibility, and understanding participants’ perceptions. Most respondents considered the approach they reported was optimal, though several reconsidered this. Four AE grading, and three causality assessment approaches were reported. Combining general and structured questions about non-study drug use were considered useful for revealing and identifying specific medicines, while pictures could enhance reports, particularly in areas of low literacy.ConclusionsIt is critical to evaluate the safety of anti-malarial drugs being deployed in large, diverse populations. Many studies would be suitable for contributing to a larger body of evidence for answering questions on harm. However this survey showed that various methods are used to obtain relevant data, which could influence study results. As the best practices for obtaining such data are unclear, anti-malarial clinical researchers should work towards consensus about the selection and/or design of optimal methods.