Browsing by Author "Blockman, Marc"

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    Open Access
    AGREE to disagree: critical appraisal and the publication of practice guidelines
    (2014) Wiseman, Roger; Cohen, Karen; Gray, Andy; Jamaloodien, Khadija; Kredo, Tamara; Miot, Jacqui; Parrish, Andy; Taylor, Bettina; Blockman, Marc
    Faced by an explosion in available evidence for multiple new treatments, busy clinicians value guidelines that are clear, reliable, unbiased and locally applicable. Finding them can be difficult, however. The science of guideline development has moved rapidly in the past decade, resulting in a more robust and systematic process. However, just as the language of evidence-based medicine can be subverted to sound convincing while hiding errors and biases, so too guidelines may look convincing but lack many of the elements needed to ensure quality of care. In particular, the pharmaceutical and health technology industries are intensely aware of the marketing potential offered by widely disseminated and ostensibly neutral documents that ultimately influence medical practice.
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    Cases of antiretroviral-associated gynaecomastia reported to the National HIV & Tuberculosis Health Care Worker Hotline in South Africa
    (BioMed Central, 2016-11-16) Njuguna, Christine; Swart, Annoesjka; Blockman, Marc; Maartens, Gary; Chisholm, Briony; Stewart, Annemie; Uys, Anri; Cohen, Karen
    Background: Gynaecomastia is associated with exposure to antiretroviral therapy (ART), in particular efavirenz. There is limited data on clinical characteristics of patients with ART-associated gynaecomastia in resource-limited settings and little guidance on the optimal management of this adverse drug reaction (ADR). We describe the clinical characteristics, management and outcomes of gynaecomastia cases reported to the National HIV & Tuberculosis Health Care Worker Hotline in South Africa. Methods: We identified all gynaecomastia cases in adolescent boys and men on ART reported to the hotline between June 2013 and July 2014. We collected follow up data telephonically at monthly intervals to document clinical management and outcomes. Results: We received 51 reports of gynaecomastia between June 2013 and July 2014; 11% of the 475 patient-specific ADR queries to the hotline. All patients were on efavirenz-based ART. Mean age was 34 years (standard deviation 12) and seven were adolescents. The median onset of gynaecomastia was 15 months after efavirenz initiation (interquartile range 6–42). Gynaecomastia was bilateral in 29 patients (57%) and unilateral in 16 (31%). Serum testosterone was quantified in 25 of 35 patients with follow up data, and was low in 2 (8%). Efavirenz was replaced with an alternative antiretroviral in 29/35 patients (83%) and gynaecomastia improved in 20/29 (69%). Conclusions: Gynaecomastia was a frequently reported ADR in our setting, occurring with prolonged efavirenz exposure. Testosterone was low in the minority of tested cases. Most clinicians elected to switch patients off efavirenz, and gynaecomastia improved in the majority.
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    Open Access
    The impact of the National HIV Health Care Worker Hotline on patient care in South Africa
    (BioMed Central Ltd, 2011) Chisholm, Briony; Cohen, Karen; Blockman, Marc; Kinkel, Hans-Friedemann; Kredo, Tamara; Swart, Annoesjka
    BACKGROUND:South Africa has a huge burden of illness due to HIV infection. Many health care workers managing HIV infected patients, particularly those in rural areas and primary care health facilities, have minimal access to information resources and to advice and support from experienced clinicians. The Medicines Information Centre, based in the Division of Clinical Pharmacology at the University of Cape Town, has been running the National HIV Health Care Worker (HCW) Hotline since 2008, providing free information for HIV treatment-related queries via telephone, fax and e-mail. RESULTS: A questionnaire-based study showed that 224 (44%) of the 511 calls that were received by the hotline during the 2-month study period were patient-specific. Ninety-four completed questionnaires were included in the analysis. Of these, 72 (77%) were from doctors, 13 (14%) from pharmacists and 9 (10%) from nurses. 96% of the callers surveyed took an action based on the advice received from the National HIV HCW Hotline. The majority of actions concerned the start, dose adaption, change, or discontinuation of medicines. Less frequent actions taken were adherence and lifestyle counselling, further investigations, referring or admission of patients. CONCLUSIONS: The information provided by the National HIV HCW Hotline on patient-specific requests has a direct impact on the management of patients.
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    Leaving the party - withdrawal of South African essential medicines
    (2005) Wilmshurst, Jo M; Blockman, Marc; Argent, Andrew; Gordon-Graham, Eugenie; Thomas, Jenny; Whitelaw, Andrew; McCulloch, Mignon; Ramiah, Malitha; Dyeshana, H; Ireland, Joe
    In August 2004 pharmacies and drug depots were advised that the sole supplier of parenteral phenobarbitone in South Africa, essential for the management of status epilepticus in children, was stopping production at the end of the same year. Alternative protocols for the management of status epilepticus resulted in more children requiring intensive care intervention (N = 9) at the Red Cross Children’s Hospital, over a 2-month period, than had occurred in any 12-month period since 2000 (2000 N = 3, 2001 N = 1, 2002 N = 1, 2003 N = 2, 2004 N = 7). Other agents that have suffered or are at risk of the same fate are sodium nitroprusside, labetalol and esmolol. Sodium nitroprusside is used extensively in the peri-operative period in cardiac patients requiring after-load reduction. There are no other nitrates with equivalent efficacy. Supply was stopped in 2005 and only reinstated after the pharmaceutical company was contacted directly. Supply of labetalol and esmolol was stopped without warning. Without access to these products it is necessary to resort to agents that are not appropriate for paediatric use. Acetylcysteine (Parvolex), used in the management of acetaminophen overdose, also became unavailable and the supply was re-established only after direct communication with the pharmaceutical company.
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    Poor anticoagulation control in patients taking warfarin at a tertiary and district-level prothrombin clinic in Cape Town, South Africa
    (2018) Ebrahim, Ismaeel; Blockman, Marc; Bryer, Alan
    Background. Warfarin is the most commonly used anticoagulant for both primary and secondary prevention of thromboembolism. For anticoagulation efficacy, the international normalised ratio (INR) needs to be within the therapeutic range for at least 65% of time on warfarin. Objectives. To describe INR control in patients on long-term warfarin and identified predictors of good INR control at two dedicated warfarin follow-up clinics in Cape Town, South Africa (SA). Methods. We reviewed clinical records of patients in care at the INR clinics at Mitchell’s Plain Community Health Centre and Groote Schuur Hospital. We included patients who had been on warfarin therapy for at least 27 months and excluded patients with <6 months of INR monitoring data or a >70-day gap between INR tests in the calculation period, and if >25% of follow-up time was at an alternative site. The time in therapeutic range (TTR) over 180 days using the Rosendaal method was calculated, and we categorised INR control as good if the TTR was ≥65%. We constructed a multivariate logistic regression model to identify associations with good INR control. Results. We included 363 patients, with a median age of 55 years (interquartile range (IQR) 44 - 64), of whom 65.6% were women. The most common indications for warfarin were valvular heart disease (45.7%) and atrial fibrillation (25.1%). The mean TTR was 47%, with only 91/363 patients having good INR control. In a multivariate model adjusted for age, sex, clinic and target INR, patients aged ≥55 years were more likely to have good INR control than younger patients (adjusted odds ratio 1.69, 95% confidence interval 1.03 - 2.79). Poorly controlled patients had more frequent INR monitoring than those with good INR control, with a median of 8 INRs (IQR 6 - 10) v. 6 INRs (IQR 5 - 8) in the 180-day period (p<0.0001). Conclusion. Only 25.1% of patients in our study achieved good INR control, despite regular INR monitoring. There is an urgent need to improve anticoagulation control of patients receiving warfarin in SA. Validated dosing algorithms are required, and access to lower warfarin dosage formulations may optimise individual dose titration. Advocacy for these formulations is advised.
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    Prevalence and risk factors of chronic diseases of lifestyles in endurance runners
    (2018) Language, Sarah; Burgess, Theresa; Blockman, Marc
    Background: Chronic diseases of lifestyle (CDL) are associated with high rates of morbidity and mortality in South Africa. Although prevalence of CDL has been established in the general population, there is limited research regarding the prevalence and risk factors for CDL in individuals taking part in regular physical activity. Endurance running is a popular sport, with growing levels of participation. Anecdotally, many individuals who participate in endurance running do not undergo formal pre-participation cardiovascular screening. It is also unclear if endurance runners are meeting the World Health Organisation’s recommended weekly moderate to vigorous intensity physical activity hours, or if they have other risk factors for CDL. It is therefore important to establish the prevalence and risk factors of CDL in this active population. Aim and Objectives: The aim of this study was to determine the prevalence of CDL and the associated risk factors in endurance runners in South Africa. The specific objectives of the study were: (a) to determine the presence of risk factors for the development of chronic diseases of lifestyle, including body mass index (BMI), waist circumference, body fat percentage, blood pressure, blood glucose, blood cholesterol, smoking history, dietary intake and weekly physical activity time in South African endurance runners; (b) to determine the presence of non-modifiable risk factors to the development of CDL, namely age and income, in South African endurance runners; (c) to determine whether South African endurance runners are fulfilling the World Health Organization’s recommended weekly moderate to vigorous intensity physical activity hours; and (d) to assess whether there are any relationships between the running characteristics, namely weekly training hours, running speed and level of competition; and the risk factors for chronic diseases of lifestyle. Methods: This study had an analytical, cross-sectional design. Two hundred participants between the ages of 18 to 69 years old, who reported endurance running as their main sport, and ran at least three kilometres twice a week for the past year were included in the study. Participants were excluded if they were pregnant or within six months post-partum, had an injury that required a minimum of two weeks rest or did not complete the questionnaire or physical testing component of the testing process. Participants were recruited through local running clubs and running races in the areas of Nelspruit, Mpumalanga and Cape Town, Western Cape. All participants gave written informed consent, and completed a questionnaire including socio-demographic characteristics, running training characteristics, the International Physical Activity Questionnaire short questionnaire, the modified Borg scale of perceived exertion, and the five-a-day community evaluation tool. Body mass, stature, skin folds and waist circumference were assessed. Blood pressure was measured using an automatic blood pressure monitor. A finger prick test was used to determine random blood glucose and cholesterol concentrations. Participants were requested to fast for three hours prior to testing to standardise the test in a non-fasted state (20). Results: One hundred and twenty four (62%) participants were found to have at least one risk factor for CDL. A high BMI was the most common risk factor for CDL (n=90; 45%). Nineteen participants (9.5%) did not meet the recommended duration of 150 minutes of physical activity per week. Seven percent of female participants (n=7) smoked, which is equivalent to the female population average of South Africa. Multiple risk factors were identified in fifty seven (28.5%) participants, ranging from two risk factors (n=37; 18.5%) to six risk factors (n=1; 0.5%). The majority of participants had no prior medical diagnosis of CDL or risk factors for CDL. The overall self-reported prevalence of a medically diagnosed CDL was 5.5% (n=11). Type 2 diabetes was the most commonly diagnosed CDL (n=6; 3%). Waist circumference, systolic blood pressure and cholesterol were significantly elevated in the older age group. There were no significant differences in risk factors for CDL according to income status. Female runners had significantly higher average sitting times compared to male runners. In addition, participants with a BMI ≥ 25 kg.m-2 had significantly slower 10 km running speeds and lower average weekly training distance, compared to participants with BMI within normal ranges. Conclusion: A high prevalence of risk factors for CDL was identified in South African endurance runners. The majority of endurance runners included in this sample are fulfilling the World Health Organisation’s recommended weekly moderate to vigorous intensity hours. However, the endurance runners in this study remain at risk for developing a CDL due to the presence of other risk factors for CDL. The knowledge and awareness of risk factors for CDL among South African endurance runners needs to be further investigated. Health care professionals are required to improve the prevention and management of risk factors of CDL through education and promotion of healthy lifestyles. A stronger emphasis on the prevention of risk factors for CDL in South African endurance runners is needed.
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    A rising-dose tolerance study in health human subjects, examining increasing doses of chlorproguanil with a constant dose of dapsone
    (2002) Blockman, Marc; Smith, Pete
    Includes bibliographical references.
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    A school-based intervention for improving malaria-related knowledge and practices in Maputo Province, Mozambique : a randomised controlled trial
    (2008) Machai, Maria José Pires; Barnes, Karen I.; Blockman, Marc
    The aim of the study was to evaluate the impact of a school-based malaria education intervention and its effectiveness in the changing knowledge and practices related to malaria at randomly selected schools in Maputo Province.
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    Self-Reported Antenatal Medicines Use Among Women Living with and Without HIV in Western Cape, South Africa: A Sub-Analysis of the B Positive Cohort Study
    (2022) Elzouki, Zaineb; Mehta, Ushma; Blockman, Marc
    Globally, innumerable women take medication while they are pregnant, and this trend is growing. The pipeline of medicines targeting maternal comorbidities is expanding. However, for most medicines, there is insufficient data on their safety in pregnancy. In addition, women may be taking medication for chronic or acute conditions before they recognize that they are pregnant. This study compared the self-reported pattern of medicine use during the course of pregnancy in a cohort of pregnant women either living with or without HIV; seeking care at Gugulethu primary health care obstetric clinic in Western Cape, South Africa. Data on medicine use was collected over 3 antenatal visits. Medications reported were manually classified and coded by a clinical pharmacist and medical doctor. Structured interviews using a detailed questionnaire on medication use were administered to n=989 pregnant women. Women who had an ectopic pregnancy or an elective termination of pregnancy (TOP) were excluded from the analysis. 982 of these women were included in our analysis (n=507 HIV-negative and n=475 HIV positive). Of these, 39 (4.0%) did not report taking any medicine during pregnancy. Most 907 (92.3%) pregnant women reported using at least one over-the-counter medicine (OTC) and the majority, 601 (61.2%), at least one prescription medicine. A total of 36 (3.7%) reported using at least one herbal or traditional medicine over the course of the pregnancy. Pregnant women living with HIV were significantly less likely to report use of OTC medicine (56.2% vs 77.7%, p=<0.001). Pregnant women living with HIV also reported less herbal medicine use (2.9% vs 4.7%, p=0.07) compared to pregnant women living without HIV, though the effect was non-significant within this sample. Excluding antiretroviral medicines, prescription medicine use was essentially the same among pregnant women living with and without HIV (30.5% vs 30.2%, p=0.96). Exposure to medicines known to be potentially teratogenic or unsafe in pregnancy was reported in 300 (30.65%) pregnant women, with aspirin 238 (24.2%) and nonsteroidal anti-inflammatory medicines 46 (4.7%) medicines being the most reported. This study provides valuable information on self-reported medication use among pregnant women living with and without HIV in a South African primary healthcare setting. Medicine use was widespread in the study cohort, particularly OTC, with high prevalence of potentially unsafe medicines used during pregnancy. Our finding highlights the urgent need to build awareness around rational and safe medicine use among antenatal staff; pharmacists; and women of child-bearing age in South Africa, encouraging the taking of a thorough history of medicine exposure throughout the antenatal period.
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    A survey of hypertensive practices at two community health centres in Cape Town
    (Health and Medical Publishing Group, 2007) Rayner, Brian; Blockman, Marc; Baines, Donette; Trinder, Trinder
    Background: Control of hypertension remains an elusive goal, but doctors' non-compliance with guidelines, patient attitudes and adherence to treatment, and poor delivery of care at clinics are important contributing factors. Objectives: To determine the overall quality of hypertensive care, and compliance with current hypertension guidelines at community health centres (CHCs) in the Western Cape. Methods. Consecutive patients attending hypertension clinics at two CHCs were selected to participate. A questionnaire was designed to determine patient demographics, doctors' compliance with hypertension guidelines, factors leading to treatment non-adherence, and delivery of care. Accuracy of blood pressure (BP) recording was evaluated by comparing the clinic BP with that measured using an approved manometer. Results: One hundred and sixty-one patients were evaluated, 100 from CHC 1 and 61 from CHC 2. There was no difference in both control systolic and diastolic BP measured by the hypertension nurse (147.9 v. 144.8 mmHg, p = 0.45, and 89.3 v. 85.6 mmHg, p = 0.14) respectively. All clinic BP readings were recorded to the nearest 10 mmHg mercury. The difference in both systolic and diastolic BP > 10 mmHg between the clinic and control BP was significantly greater at CHC 2 than CHC 1 (28% v. 56%, p = 0.005, and 43% v. 64%, p = 0.007) respectively. Overall, 39.8% of patients had a systolic and diastolic BP < 140 and < 90 mmHg. The mean number of antihypertensive drugs was 2.4 per patient. The use of non-steroidal antiinflammatory drugs (NSAIDs) and tricyclic antidepressants was high at both centres, and few patients underwent basic investigations, lifestyle interventions, risk stratification or global cardiovascular risk reduction. Conclusions: 39.8% of patients achieved a BP < 140/90 mmHg. There is significant scope for improvement in prescription of medication, application of uniform lifestyle changes, and avoidance of NSAIDs and tricyclic antidepressants. Major deficiencies were identified in BP measurement, assessment of target organ damage, risk stratification and the reduction of overall cardiovascular risk.