Analysis of macrolide antibiotics

The following macrolide antibiotics have been covered in this review: erythromycin and its related substances, azithromycin, clarithromycin, dirithromycin, roxithromycin, flurithromycin, josamycin, rokitamycin, kitasamycin, mycinamycin, mirosamycin, oleandomycin, rosaramicin, spiramycin and tylosin. The application of various thin-layer chromatography, paper chromatography, gas chromatography, high-performance liquid chromatography and capillary zone electrophoresis procedures for their analysis are described. These techniques have been applied to the separation and quantitative analysis of the macrolides in fermentation media, purity assessment of raw materials, assay of pharmaceutical dosage forms and the measurement of clinically useful macrolide antibiotics in biological samples such as blood, plasma, serum, urine and tissues. Data relating to the chromatographic behaviour of some macrolide antibiotics as well as the various detection methods used, such as bioautography, UV spectrophotometry, fluorometry, electrochemical detection, chemiluminescence and mass spectrometry techniques are also included

Reply: Methotrexate neurotoxicity due to drug interactions: an inadequate folinic acid effect

No abstract available

Drug interactions may be important risk factors for methotrexate neurotoxicity, particularly in pediatric leukemia patients

Purpose: Methotrexate administration is associated with frequent adverse neurological events during treatment for childhood acute lymphoblastic leukemia. Here, we present evidence to support the role of common drug interactions and low vitamin B12 levels in potentiating methotrexate neurotoxicity. Methods: We review the published evidence and highlight key potential drug interactions as well as present clinical evidence of severe methotrexate neurotoxicity in conjunction with nitrous oxide anesthesia and measurements of vitamin B12 levels among pediatric leukemia patients during therapy. Results: We describe a very plausible mechanism for methotrexate neurotoxicity in pediatric leukemia patients involving reduction in methionine and consequential disruption of myelin production. We provide evidence that a number of commonly prescribed drugs in pediatric leukemia management interact with the same folate biosynthetic pathways and/or reduce functional vitamin B12 levels and hence are likely to increase the toxicity of methotrexate in these patients. We also present a brief case study supporting out hypothesis that nitrous oxide contributes to methotrexate neurotoxicity and a nutritional study, showing that patients. Conclusions: Use of nitrous oxide in pediatric leukemia patients at the same time as methotrexate use should be avoided especially as many suitable alternative anesthetic agents exist. Clinicians should consider monitoring levels of vitamin B12 in patients suspected of having methotrexate- induced neurotoxic effects

Consensus definitions of 14 severe acute toxic effects for childhood lymphoblastic leukaemia treatment: a Delphi consensus

Although there are high survival rates for children with acute lymphoblastic leukaemia, their outcome is often counterbalanced by the burden of toxic effects. This is because reported frequencies vary widely across studies, partly because of diverse definitions of toxic effects. Using the Delphi method, 15 international childhood acute lymphoblastic leukaemia study groups assessed acute lymphoblastic leukaemia protocols to address toxic effects that were to be considered by the Ponte di Legno working group. 14 acute toxic effects (hypersensitivity to asparaginase, hyperlipidaemia, osteonecrosis, asparaginase-associated pancreatitis, arterial hypertension, posterior reversible encephalopathy syndrome, seizures, depressed level of consciousness, methotrexate-related stroke-like syndrome, peripheral neuropathy, high-dose methotrexate-related nephrotoxicity, sinusoidal obstructive syndrome, thromboembolism, and Pneumocystis jirovecii pneumonia) that are serious but too rare to be addressed comprehensively within any single group, or are deemed to need consensus definitions for reliable incidence comparisons, were selected for assessment. Our results showed that none of the protocols addressed all 14 toxic effects, that no two protocols shared identical definitions of all toxic effects, and that no toxic effect definition was shared by all protocols. Using the Delphi method over three face-to-face plenary meetings, consensus definitions were obtained for all 14 toxic effects. In the overall assessment of outcome of acute lymphoblastic leukaemia treatment, these expert opinion-based definitions will allow reliable comparisons of frequencies and severities of acute toxic effects across treatment protocols, and facilitate international research on cause, guidelines for treatment adaptation, preventive strategies, and development of consensus algorithms for reporting on acute lymphoblastic leukaemia treatment

Identifying and exploring the self-management strategies used by childhood cancer survivors.

PurposeChildhood cancer survivors (CCSs) are at increased risk of chronic health problems.Effective self-management could help CCSs cope with the challenges that accompanysurvivorship, and reduce their risk of developing further health problems. There is littleevidence about the extent to which CCSs engage with self-management and thespecific strategies they use. This study aimed to identify and explore the strategies thatCCSs use to manage the consequences of cancer.MethodsTwenty-four CCSs were recruited via follow-up clinics. Participants completed a semi-structured interview which was audio-recorded and transcribed. Directed contentanalysis was used to identify self-reported self-management strategies and categorisethem into main self-management types.ResultsCCSs reported 118 specific self-management strategies which fell under 20 main self-management strategy types. All CCSs reported using several main self-managementstrategy types and specific self-management strategies. Main strategy types used byall CCSs were: ‘adopting a healthy lifestyle’, ‘self-motivating’, ‘using support’, a ‘reasoned decision making’ and ‘creating a healthy environment’. The most commonspecific self-management strategies were: ‘receiving family support’ (n=20) and‘attending follow-up and screening appointments’ (n=20).ConclusionsThis is the first study which has enabled CCSs to self-report the numerous strategiesthey employ to look after their health and wellbeing, contributing to a morecomprehensive picture of self-management in CCSs.Implications for Cancer SurvivorsThese findings may increase healthcare professionals’ awareness of the many ways inwhich CCSs manage their health and is a valuable first step in the development of asupported self-management intervention for CCSs in follow-up car

Recommendations for gonadotoxicity surveillance in male childhood, adolescent, and young adult cancer survivors : a report from the International Late Effects of Childhood Cancer Guideline Harmonization Group in collaboration with the PanCareSurFup Consortium

Treatment with chemotherapy, radiotherapy, or surgery that involves reproductive organs can cause impaired spermatogenesis, testosterone deficiency, and physical sexual dysfunction in male pubertal, adolescent, and young adult cancer survivors. Guidelines for surveillance and management of potential adverse effects could improve cancer survivors' health and quality of life. Surveillance recommendations vary considerably, causing uncertainty about optimum screening practices. This clinical practice guideline recommended by the International Late Effects of Childhood Cancer Guideline Harmonization Group in collaboration with the PanCareSurFup Consortium, developed using evidence-based methodology, critically synthesises surveillance recommendations for gonadotoxicity in male childhood, adolescent, and young adult (CAYA) cancer survivors. The recommendations were developed by an international multidisciplinary panel including 25 experts in relevant medical specialties, using a consistent and transparent process. Recommendations were graded according to the strength of underlying evidence and potential benefit gained by early detection and appropriate management. The aim of the recommendations is to enhance evidence-based care for male CAYA cancer survivors. The guidelines reveal the paucity of high-quality evidence, highlighting the need for further targeted research.Peer reviewe

Bioequivalence assessment of generic products an innovative South African approach

Concurrent with the implementation of new legislation mandating Generic Substitution in South Africa, a new set of guidelines for bioavailability and bioequivalence have been published. Since one of the main objectives of the new legislation in South Africa relating to Generic Substitution is to ensure that medicines of high quality, safety, and efficacy are made more accessible and more affordable to the wider public, the need to speed up approval of such multi-source products has become a regulatory priority. In order to facilitate this process, various bioequivalence issues have been addressed including important issues such as the acceptance criteria and associated bioequivalence intervals, use of a foreign reference product and the issue of assessing highly variable drugs (HVDs). In addition, dispensations have been made with respect to food effect assessment and variability relating to genetic polymorphism in drug metabolism (genotyping/phenotyping). Furthermore, the use of “old” biostudies submitted in support of an application is subject to expiry date. Acceptance of appropriate data requires that specific criteria such as Cmax and AUC, in addition to the usual considerations, also meet the limits specified by the particular registration authority of the country where such products are intended to be marketed. Generally, these limits require that the 90% confidence interval (CI) for AUC and Cmax test/reference ratios lies within the acceptance interval of 0.80–1.25 calculated using log-transformed data. While such acceptance criteria are, in general, ubiquitous, some differences in acceptance criteria do exist between various countries. The new guidelines for bioavailability/bioequivalence studies developed by the South African regulatory authority, the Medicines Control Council (MCC), makes provision for highly variable drugs and the use of a non-South African reference product. The MCC requires that the acceptance criterion for Cmax ratios be set at 0.75–1.33 while maintaining AUC ratios at 0.80–1.25 using a 90% CI. Furthermore, provision is made to apply scaling based on average bioequivalence assessment and, as an interim measure, consideration has also been given to the use of a foreign reference product provided that equivalence between that product and the innovator product currently available on the South African market can be shown using in vitro testing