/pdf/annual-review-of-biophysics-and-biomolecular-structure-3z5o3wd5xs.pdf

Annual review of biophysics and biomolecular structure

Purpose. —To resolve discrepancies in previous systematic overviews and provide estimates of the effect of stress ulcer prophylaxis on gastrointestinal bleeding, pneumonia, and mortality in critically ill patients. Data Identification. —Computerized search of published and unpublished research, bibliographies, pharmaceutical and personal files, and conference abstract reports. Study Selection. —Independent review of 269 articles identified 63 relevant randomized trials for inclusion. Data Abstraction. —We made independent, duplicate assessment of the methodologic quality, population, intervention, and outcomes of each trial. Results. —The source of discrepancies between prior meta-analyses included incomplete identification of relevant studies, differential inclusion of non—English language and nonrandomized trials, different definitions of bleeding, provision of additional information through direct correspondence with authors, and different statistical methods. The current overview demonstrates that prophylaxis with histamine2-receptor antagonists decreases the incidence of overt gastrointestinal bleeding (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.42 to 0.79) and clinically important bleeding (OR, 0.44; 95% CI, 0.22 to 0.88). There is a trend toward decreased overt bleeding when antacids are compared with no therapy (OR, 0.66; 95% CI, 0.37 to 1.17). Histamine2-receptor antagonists and antacids are associated with a trend toward lower clinically important bleeding rates than sucralfate is. There is a trend toward an increased risk of pneumonia associated with histamine2-receptor antagonists as compared with no prophylaxis (OR, 1.25; 95% CI, 0.78 to 2.00). Sucralfate is associated with a lower incidence of nosocomial pneumonia when compared with antacids (OR, 0.80; 95% CI, 0.56 to 1.15) and histamine2-receptor antagonists (OR, 0.77; 95% CI, 0.60 to 1.01). Sucralfate is also associated with a reduced mortality rate (OR, 0.73; 95% CI, 0.54 to 0.97) relative to antacids and to histamine2-receptor antagonists (OR, 0.83; 95% CI, 0.63 to 1.09). Conclusions. —Our results emphasize the need for registries to include all randomized trials and demonstrate the importance of explicit methodology for systematic reviews. There is strong evidence of reduced clinically important gastrointestinal bleeding with histamine2-receptor antagonists. Sucralfate may be as effective in reducing bleeding as gastric pH—altering drugs and is associated with lower rates of pneumonia and mortality. However, the data are insufficient to determine the net effect of sucralfate compared with no prophylaxis. (JAMA. 1996;275:308-314)

Stress Ulcer Prophylaxis in Critically Ill Patients Resolving Discordant Meta-Analyses

Importance Substandard and falsified medicines burden health systems by diverting resources to ineffective or harmful therapies, causing medical complications and prolonging illnesses. However, the prevalence and economic impact of poor-quality medicines is unclear. Objective To conduct a systematic review and meta-analysis to assess the prevalence and estimated economic burden of substandard and falsified essential medicines in low- and middle-income countries. Data Sources Five databases (PubMed, EconLit, Global Health, Embase, and Scopus) were searched from inception until November 3, 2017. Study Selection Publications were assessed to determine whether they examined medicine quality and the prevalence and/or economic burden of substandard and falsified medicines in low- and middle-income countries. Studies with a sample size of 50 or more were included in the meta-analysis. Data Extraction and Synthesis The study is registered in PROSPERO and reported via the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Study quality was assessed using an adapted Medicine Quality Assessment Reporting Guidelines scoring metric. Multiple reviewers conducted the data extraction and quality assessment independently. Main Outcomes and Measures Prevalence and/or estimated economic impact of substandard and falsified medicines. Results Two hundred sixty-five studies that estimated the prevalence of poor-quality essential medicines in low- and middle-income countries were identified. Among 96 studies that tested 50 samples or more (67 839 total drug samples), overall prevalence of poor-quality medicines was 13.6% (95% CI, 11.0%-16.3%), with regional prevalence of 18.7% in Africa (95% CI, 12.9%-24.5%) and 13.7% in Asia (95% CI, 8.2%-19.1%). Of studies included in the meta-analysis, 19.1% (95% CI, 15.0%-23.3%) of antimalarials and 12.4% (95% CI, 7.1%-17.7%) of antibiotics were substandard or falsified. Eight approximations of the economic impact, focused primarily on market size, with poor or undisclosed methods in estimation were identified, ranging from $10 billion to $200 billion. Conclusions and Relevance Poor-quality essential medicines are a substantial and understudied problem. Methodological standards for prevalence and rigorous economic studies estimating the burden beyond market size are needed to accurately assess the scope of the issue and inform efforts to address it. Global collaborative efforts are needed to improve supply-chain management, surveillance, and regulatory capacity in low- and middle-income countries to reduce the threat of poor-quality medicines. Trial Registration PROSPERO Identifier:CRD42017080266

/pdf/prevalence-and-estimated-economic-burden-of-substandard-and-45ba4x47vl.pdf

Prevalence and Estimated Economic Burden of Substandard and Falsified Medicines in Low- and Middle-Income Countries: A Systematic Review and Meta-analysis.

The presence of mycotoxins in herbal medicines is an established problem throughout the entire world. The sensitive and accurate analysis of mycotoxin in complicated matrices (e.g., herbs) typically involves challenging sample pretreatment procedures and an efficient detection instrument. However, although numerous reviews have been published regarding the occurrence of mycotoxins in herbal medicines, few of them provided a detailed summary of related analytical methods for mycotoxin determination. This review focuses on analytical techniques including sampling, extraction, cleanup, and detection for mycotoxin determination in herbal medicines established within the past ten years. Dedicated sections of this article address the significant developments in sample preparation, and highlight the importance of this procedure in the analytical technology. This review also summarizes conventional chromatographic techniques for mycotoxin qualification or quantitation, as well as recent studies regarding the development and application of screening assays such as enzyme-linked immunosorbent assays, lateral flow immunoassays, aptamer-based lateral flow assays, and cytometric bead arrays. The present work provides a good insight regarding the advanced research that has been done and closes with an indication of future demand for the emerging technologies.

A Review of Current Methods for Analysis of Mycotoxins in Herbal Medicines.

Current status of major mycotoxins contamination in food and feed in Africa

Utilization of herbal products is a major concern due to the possibility of contamination by toxigenic fungi that are mycotoxin producers such as Aspergillus species during processing and packaging. Research was carried out to determine the presence of aflatoxins and fumonisins in herbal medicinal products sold in Eldoret and Mombasa towns in Kenya. The study employed both exploratory and laboratory experimental design. The herbal products were purchased from the market and transported to Kenya Medical Research Institute for processing and analysis. Fungal contaminants were determined according to Pharmacopoeia specifications. The toxins were quantified using ELISA based technique. The genus Aspergillus was the most dominant followed by Penicillium. Fungal counts ranged between 1 CFU/g and >1000 cfu/g. Analysis of variance showed that the rate of fungal contaminants for Eldoret and Mombasa samples had significant association (). Aflatoxin levels ranged from 1 to 24 ppb, while fumonisin levels ranged from 1 to >20 ppb. Only 31% of samples met the standards for microbial limits as specified in Pharmacopoeia. There is need for product microbial quality improvement through proper harvesting, processing, storage, and marketing. It is recommended that a policy be enacted to enable regulation of herbal products in Kenya.

/pdf/risk-of-fungi-associated-with-aflatoxin-and-fumonisin-in-4f3qofsrld.pdf

Risk of Fungi Associated with Aflatoxin and Fumonisin in Medicinal Herbal Products in the Kenyan Market

Herbal products are used worldwide for the treatment and prevention of various diseases and currently represent a substantial proportion of the global drug market. However, these products have the potential of being contaminated by different microorganisms due to poor hygienic practices during handling, processing and packaging. The main aim of this study was to evaluate microbial quality of herbal products marketed to the general population in Eldoret and Mombasa, Kenya. The study employed an exploratory as well as laboratory based experimental design. The herbal products were purchased from the markets and transported to Kenya Medical Research Institute laboratories for processing and analysis. Microbial contaminants were determined according to Pharmacopoeias and World Health Organization standards. Microbial pathogens were isolated, identified and drug susceptibility test was done as per National Laboratory Standards Institute protocol. The herbal products were in-form of powders, liquids, tablets, oils and capsules. Bacterial contamination was observed in 90% of the total samples and those with >1000×104cfu/gm or ml was 20% for Eldoret and 46% for Mombasa samples. Analysis of variance showed that the rate of microbial contaminants for Eldoret and Mombasa samples had no significant association (p = 0.084). Bacteria belonging to seven genera were isolated and antibiotic susceptibility test showed that 13.2% of the bacteria isolates were resistant. Multidrug resistance was observed with Klebsiella pneumonia, Shigella sonnei, Serratia erwinia, Serratia liquefaciens and Proteus penneri. These findings imply that conditions during harvest or postharvest processing of herbal products were unsanitary. Proper handling and storage of herbs should be observed in order to reduce the amount of microbial contaminants. Only 16% of herbal product samples evaluated met the standards for microbial limits as specified in Pharmacopoeias. Thus, emphasis on improvement of plant material quality and establishing better hygienic conditions during production of herbal medicines is recommended.

Bacteria Contaminants and their Antibiotic Sensitivity from Selected Herbal Medicinal Products from Eldoret and Mombasa, Kenya

Two sterols, β-sitosterol and stigmasterol, were isolated from the stem bark of Combretum fragrans . The identity of these compounds was established by spectral analysis.

Phytosterols from the stem bark of Combretum fragrans

Background: Prescribing is said to be irrational if it does not conform to good standards of treatment. Irrational prescribing leads to increased cost of drug therapy, increased risk for adverse drug reactions and emergence of drug resistance. Objective: The study objective was to determine the quality and patterns of prescribing in Makueni County Referral Hospital, Kenya, using World Health Organization prescribing indicators. Methodology: The design was a descriptive retrospective cross-sectional study. Data was abstracted from 824 patient encounters selected through quasi-random sampling. Data was collected from the sampled prescriptions using a pre-tested data collection form, entered into and analyzed using Stata version 10.0 software. Results: The mean number of drugs per patient encounter was 2.7. Only 45.5% of the total drugs were prescribed using generic names. Antibiotics and injections were prescribed in 74% and 13.2% of the prescriptions surveyed respectively. Discussion: On average, inpatients received a higher number of drugs per encounter compared to outpatients, probably because they usually have more severe disease than outpatients which may require management with more drugs. Conclusion: The results showed a trend towards irrational prescribing, particularly polypharmacy, underuse of generic names and over-prescription of antibiotics. Relevant educational, managerial and regulatory interventions are recommended to remedy the problems. Keywords: Irrational prescribing, prescribing indicators, polypharmacy

/pdf/patterns-of-prescribing-practices-in-makueni-county-referral-2heuom9ufr.pdf

Patterns of Prescribing Practices in Makueni County Referral Hospital, Kenya

Malaria is a major health problem in sub-Saharan Africa where over 90% of the world’s malaria cases occur Artemisinin-based combination therapy (ACT) is recommended by the World Health Organization as first-line and second-line treatments for uncomplicated falciparum malaria However, there are a growing number of reports of sub-standard and falsified anti-malarial medicines in sub-Saharan Africa A cross-sectional study was conducted in Embu County, Kenya on the quality of anti-malarial medicines available in public and private facilities Sampling of anti-malarial medicines from public and private hospitals, health centers and pharmacies was conducted between May and June 2014 Quality control tests were performed at the Drug Analysis and Research Unit, University of Nairobi, using ultraviolet spectrophotometry and high-performance liquid chromatography A test for microbial load was also conducted for suspension formulations A total of 39 samples were collected from public and private facilities across the Embu County A visual inspection of the medicines showed no signs of sub-standard or falsification All ACT passed identification, assay and dissolution tests Of 11 suspension samples collected, none failed the microbial load test although one sample had 50 colony forming units (cfu) No oral artemisinin monotherapy medicines were encountered during the survey Amodiaquine and chloroquine monotherapy products accounted for 5% of the collected samples, despite their ban in Kenya Two herbal anti-malarial formulations were collected during the survey Sulfadoxine/pyrimethamine (SP) was also found to be available use for malaria treatment, not in accordance with malaria treatment guidelines All the anti-malarial drugs analysed in this study passed the quality control tests This is encouraging given the high malaria burden in Kenya Regulatory actions are required to counter SP and herbal products for malaria treatment

/pdf/the-quality-of-anti-malarial-medicines-in-embu-county-kenya-2cnkw52z4t.pdf

S.N. Ndwigah

Papers

Risk of Fungi Associated with Aflatoxin and Fumonisin in Medicinal Herbal Products in the Kenyan Market

Bacteria Contaminants and their Antibiotic Sensitivity from Selected Herbal Medicinal Products from Eldoret and Mombasa, Kenya

Phytosterols from the stem bark of Combretum fragrans

Patterns of Prescribing Practices in Makueni County Referral Hospital, Kenya

The quality of anti-malarial medicines in Embu County, Kenya