DLitt et Phil, PhD, MSc, CChem, CBiol, MSB, CSci, MICR F
Mulungushi University, Zambia
Livingstone, Southern | Zambia
Main Specialties: Chemical Pathology, Medical Toxicology, Pharmacology
Additional Specialties: Pharmacology; Health Professions Education
A professional Pharmacologist and Clinical Chemist with keen interest in Health Professions Education. I have a passion for innovation and creativity.
Primary Affiliation: Mulungushi University, Zambia - Livingstone, Southern , Zambia
3PubMed Central Citations
Journal of Educational Evaluation for the Health Professions. 2020;17:8.
Journal of Educational Evaluation for the Health Professions
Purpose: This study was conducted to determine whether a computer simulation of practical exercises in undergraduate medical pharmacology led to the realization of the intended learning outcomes. Methods: The study was a descriptive analysis of laboratory classes carried out using computer simulation programs. Five programs were used to teach practical pharmacology to undergraduate medical students at the Mulungushi University School of Medicine and Health Sciences. The study period was January 2018 to December 2019. The computer programs included a pharmacokinetics simulator (CyberPatient), organ bath simulator (OBSim), AutonomiCAL for simulating autonomic pharmacology, and Virtual Cat and Virtual Rat (RatCVS) for simulating cardiovascular pharmacology. Students utilized these programs during their pharmacology laboratory classes, wrote reports, and answered relevant clinical questions. Results: The 5 programs provided easy and precise platforms for students to explore concepts and demonstrate knowledge of pharmacokinetics, pharmacodynamics, autonomic and cardiovascular pharmacology, and their clinical applications. Conclusion: The programs were effective learning tools. Students’ learning was easily assessed based on their laboratory reports. Although the computer programs met medical students’ learning needs, wet laboratory exercises are also needed to meet the needs of students who require practical laboratory skills.
Med J Zambia. 2019; 46 (3):228–237
Medical Journal of Zambia
ABSTRACT Helicobacter pylori is associated with many clinical conditions including gastric and extra-gastric pathologies. Prevalence is high in most Sub-Saharan African countries where data is available. Its association with diseases is not fully established in the region. Due to emergence of antibiotic resistance, the conventional triple and quadruple therapies using proton pump inhibitors and antimicrobial agents are now obsolete. Many Western countries have revised their therapeutic guidelines with a common recommendation to determine prior patient exposure to antibiotics, determine local drug resistance patterns and eradication rates, use higher doses of proton pump inhibitors, and include bismuth sub-citrate if clarithromycin resistance is suspected. Sub-Saharan African countries lack data on these making it difficult to apply these recommendations. The countries in Sub-Saharan Africa need to recognize the growing clinical importance of H. pylori and initiate programs to determine its local epidemiology, drug resistance, and its association with diseases in the region. Collaborative effort is required to achieve these goals and establishment of regional reference laboratories for monitoring drug resistance may be helpful. Key Words: Antibiotic resistance, global perspectives, H. pylori, prevalence, Sub-Saharan Africa, therapeutic guidelines INTRODUCTION Helicobacter pylori, a gram-negative organism that infects the gastric mucosa, is associated with several gut disorders such as peptic ulcer disease, chronic gastritis, and gastric cancers1-5. Its discovery led to dramatic changes in the management of peptic ulcer disease globally, and many countries recorded significant decreases in peptic ulcer incidence6. The records notwithstanding, in many developing countries, the prevalence of Helicobacter pylori infection remains high, while the actual values in most Sub-Saharan African countries are unknown. Available data from some of the African countries indicate very high prevalence values7, 8. To a large extent, this infection is neglected in the region9, and the extent of its contribution to diseases in Africa is not clear. Helicobacter pylori infection is commonly managed with a combination of antibiotics and gastric acid lowering drugs. Therapeutic guidelines in most countries recommend either triple therapy using two antibiotics plus a proton pump inhibitor such as omeprazole or two antibiotics plus H2-receptor blocker such as ranitidine and cimetidine. Quadruple therapy involving the use of three antimicrobials and an acid reducing agent may be used in cases of failure with triple therapy. However, the effectiveness of these regimens is complicated by the emergence of drug resistance to most recommended antibiotics10-14. To this effect, most regions of the world, apart from Sub-Saharan Africa, have revised their treatment guidelines for H. pylori associated diseases. The objectives of this article are to present the current global perspectives on H. pylori treatment in the presence of emerging antibiotic resistance, and to highlight the issues and challenges associated with the pharmacotherapy of H. pylori in Africa. EPIDEMIOLOGY The global prevalence of H. pylori infections is estimated to be more than 50 %15-17. There exists great disparity in regional prevalence however18, with the advanced countries such as Switzerland and Denmark having values below 30 % while developing countries like Pakistan, Nepal, and Libya have values exceeding 75 %15. Countries in Oceania (such as Australia and New Zealand) appear to have the least prevalence values. Significant intra-regional variations also occur. Sub-Saharan African countries have the greatest burden of H. pylori infections, with many countries recording prevalence values higher than 70 %. For example, reported prevalence for the Republic of South Africa range from 51 % to 77.6 %15, 19, Nigeria 83 % – 92 %, Benin 70 % – 81 %, and Democratic Republic of the Congo 70 % – 81 %15. Eusebi and others20 recently presented a comprehensive review of the global prevalence of H. pylori infections. Most H. pylori infections are acquired in childhood21. The social determinants of this infection are similar to those associated with other neglected tropical diseases and other endemic diseases of poverty. These include poor personal and environmental hygiene, poor drinking water quality, and overcrowded accommodation22. The precise routes of disease transmission are not certain, but evidence suggests that acquisition is usually via the oral-oral or fecal-oral transmission, drinking water and often perpetuates within the family circle23-27. Although H. pylori infection has ostensibly been identified as risk factor for gastro-duodenal ulcer, chronic gastritis, and gastric cancer, the association between these disease and H. pylori infection is unpredictable: only a small proportion of H. pylori infected individuals develop disease, and manifestation of disease as a result of infection appears to be determined by multiple factors including a geographical component28-33. For example, Aitila and colleagues22 studied children with gastrointestinal complaints in Western Uganda and observed a H. pylori prevalence of 23.4 % compared to 44.3 % in another similar study in the general population in Kampala. The phenomenon initially described as the “African enigma,” whereby seropositivity does not correlate with disease burden, has now been observed in other areas of the world34-37. This has been attributed to existence of strain to strain variation in the presence of certain pathogenicity factors. PATHOGENICITY The currentknowledge of the spectrum of diseases caused by H. pylori infection has expanded. Emerging evidence shows that, inaddition to well established association between H. Pylori infection and gastrointestinal diseases such as chronicgastritis and duodenitis, gastric and duodenal ulcers, and gastricmucosa-associated lymphoid tissue (MALT) lymphoma38, 39, H. pylori is now known to be associatedwith several extra-gastric diseases such as cardiovascular, respiratory,neural, autoimmune, and metabolic diseases40-48. Several articlespresent comprehensive reviews on this topic49-52. The pathogenicity of H pylori has been linked to the presence of two genes, cagA and vacA53,55. The cagA gene is a member of the cag pathogenicity island (PAI) which encodes the CagA protein responsible for induction of interleukins and nuclear factors associated with H. pylori induced diseases3, 56, 57. The vacA gene encodes the vacoulating cytotoxin, VacA. VacA also has strong association with H. pylori pathogenicity58-60. PHARMACOTHERAPY AND DRUG RESISTANCE The conventional treatments for H. pylori infections comprise a proton pump inhibitor in combination with antibiotics. Most guidelines recommend triple therapy with Clarithromycin, metronidazole, and/or amoxicillin, with a proton pump inhibitor as first line treatment. A quadruple therapy incorporating a fourth agent such as Bismuth compounds is also highly recommended in cases of therapeutic failure. Reduction of gastric acidity is well accepted practice in the treatment of H. pylori infections. Not only is this desirable for the healing of any ulcers, but the higher gastric pH has been reported to reduce H. pylori load and increase the susceptibility of the organism to antibiotics61. The proton pump inhibitors take the lead in this respect and a higher dosage (twice daily) regiment is reported to be more effective than the standard (once daily) regiment. Recommended proton pump inhibitors include omeprazole (20 mg), rabeprazole (20 mg), lansoprazole (30 mg), esmoprazole (40 mg), and pantoprazole (40 mg). However, genetic differences may affect individual response to proton pump inhibitors61, and chronic use of proton pump inhibitors is associated with risk of gastritis and gastric cancer62-66. Histamine (H2) receptor blockers may be used as alternatives to proton pump inhibitors but their efficacy has been reported to be less than those of proton pump inhibitors67. Another class of gastric acid suppressants, potassium-competitive acid blockers exemplified by Vonoprazan, has been recommended as substitute to proton pump inhibitors for H. pylori treatment68. Vonoprazan (1-[5-(2-Fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]-N-methylmethanamine Monofumarate (TAK-438), C17H16FN3O2S), competitively and reversibly block H+/K+ ATPase. Its efficacy in the treatment of H. pylori associated conditions is reported to equal those of proton pump inhibitors, but it has its own set of adverse effects69. Clarithromycin occupies a first-line position in the antimicrobial treatment of H. pylori infections. Triple or quadruple therapies that are clarithromycin-based have demonstrated high efficacies in the eradication of H. pylori infections, especially when metronidazole is included70, 71. However, the emergence of clarithromycin resistant H. pylori strains is now a global phenomenon that challenges the a priori established therapeutic guidelines for the clinical management H. pylori infections72-74. Resistance to other recommended antibiotics such as metronidazole, levofloxacin, and amoxicillin, are now commonly reported across the globe75-77. Bismuth subcitrate is increasingly recommended for inclusion as part of first line, second line, or rescue therapy in cases of demonstrated drug resistance and shows significant improvement in eradication rates78-82. The global emergence of H. pylori resistant strains has resulted in revisions of standard therapeutic guideline for its eradication. These modifications include the ‘Kyoto Global Consensus on Helicobacter pylori gastritis’ which presented comprehensive guide for the clinical management of H. pylori gastritis83, the ‘Toronto Consensus for the Treatment of Helicobacter pylori Infection in Adults’84, and the ‘Guidelines for the management of Helicobacter pylori infection in Italy: The III Working Group Consensus Report 2015’85. These consensus statements have many things in common which include the need to determine previous antibiotic exposure, knowledge of local/regional H. pylori drug resistance patterns and eradication rates, and the inclusion of bismuth sub-citrate in therapeutic regimens if clarithromycin resistance is suspected. The consensus statements also recommended using higher doses of proton pump inhibitors e.g. twice daily dosing instead of the usual once daily dosing and avoiding repeating the same regimen that failed. Table 1 presents a summary of these consensus statements. Other therapeutic regimens have also emerged such as sequential and concomitant therapy86. In a typical sequential therapy, rabeprazole (a proton pump inhibitor) and amoxicillin were initially given for 5-7 days followed by rabeprazole, clarithromycin and metronidazole for a further 5-7 days. Concomitant therapy utilized rabeprazole, amoxicillin, clarithromycin, and metronidazole for 14 days. These recommendations are appropriate for western developed countries that have ample information on H. pylori drug resistance, and where use of the relevant antibiotics is well regulated and documented. In sub-Saharan African, antibiotics use is not stringently regulated partly because of the many cases of bacterial infections. In a recent review, Tadasse and colleagues noted the lack of recent antimicrobial resistance data in many Sub-Saharan African countries. Data from few studies indicated high levels of resistance to antimicrobial agents87. Specific H. pylori drug resistance data are also not widely available for many Sub-Saharan African countries. The few available data show alarming high rates of H. pylori resistance to recommended antibiotics13, 77, 88. In a systematic review of reports from Africa, Jaka and colleagues reported 29.2 % resistance to clarithromycin, 75.8 % resistance to metronidazole, and 72.6 % resistance to amoxicillin88. Table 1. Summary of Current Consensus Statements on H. pylori Treatment 1 Prior antibiotic exposure should be determined before initiating H pylori treatment 2. Choice of first-line antibiotic therapy should consider regional H pylori drug resistance pattern and eradication rates 3. In regions with low resistance to clarithromycin (i.e. < 15 %), first-line therapeutic regimen (triple therapy) that includes clarithromycin may be effective 4. Bismuth based quadruple therapy is highly recommended in areas with high clarithromycin resistance (i.e. > 15 %) 5. Triple, quadruple, sequential, or concomitant therapy should extend to 14 days for optimal efficacy CONCLUSION AND RECOMMENDATIONS Sub-Saharan Africa lacks reliable data on the regional and intra-country prevalence of H. pylori infections. The association between H. pylori positivity and disease is not fully established in the region. There is also no current report on the appraisal of the efficacy of the triple and quadruple therapeutic strategies adopted by many countries. Information on drug resistance is scanty. The few available reports suggest a high rate of drug resistance. For these reasons, recommending evidence-based therapeutic strategies is difficult. The way forward for Africa is to recognize the clinical importance of this neglected pathogen in the region. More studies are needed to provide national and regional epidemiological data including data on drug resistance and disease association with H pylori infection in Sub-Saharan Africa. Regional diagnostic laboratories should be established to test H pylori susceptibility. A Pan-African conference on Helicobacter pylori could provide opportunity to brain-storm on H pylori pathogenicity, prevalence and drug resistance in Africa. REFERENCES
J Educ Eval Health Prof 2013 23;10. Epub 2013 Oct 23.
Department of Health Science, College of Medicine, Nursing and Health Sciences, Fiji National University, Suva, Fiji.
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Ann Med Health Sci Res 2013;3(3):376-379
Annals of Medical and Health Sciences Research
Background: Many manuscripts submitted to biomedical journals are rejected for reasons that include low-quality of the manuscripts. Aim: The aim of this study is to identify and characterize the common errors in manuscripts submitted to medical journals based in Africa and Asia. Materials and Methods: Reviewers’ reports on 42 manuscripts were analyzed qualitatively using deductive coding, and quantitatively to determine the errors by sections of the manuscripts. The study included only reviews on full length original research articles. Results: Results showed that 66.7% (28/42) of the manuscripts had flaws in the introduction, 85.7% (36/42) in materials and methods, 66.7% (28/42) in the results, 71.4% (30/42) in discussion, 69.0% (29/42) in references, and 81.1% (34/42) in the general sections. Qualitative analysis of the reviews revealed 22 themes. Most common flaws identified were improper review of literature, provision of insufficient detailed methodology, unsystematic or illogical presentation of results, and unsupported conclusions. Others were inconsistent or nonconforming citations, and lack of good grammatical writing. Conclusions: The results show that many of the manuscripts had remarkable errors and demonstrate the need for attention to detail in study design and manuscript preparation and for further training of medical scientists in the techniques of manuscript writing for journal publication.
PHD 2012; 18(2):142-145
Pacific Health Dialog
Cent Afr J Med 1994 Aug;40(8):226-9
Department of Radiation Medicine, University of Nigeria Teaching Hospital, Enugu.
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