Time filter

Source Type

Hait S.S.E.,University of Sydney | Chaar B.,University of Sydney | McLachlan A.J.,University of Sydney | McLachlan A.J.,Center for Research and Education on Ageing | And 3 more authors.
Jordan Journal of Pharmaceutical Sciences | Year: 2015

The aim of the study was to examine the feasibility of pharmacist-led diabetes educational programme on disease control and health-related quality of life in Arabic-speaking Type 2 diabetes patients in Australia. Participants’ HbA1c values improved over the three months period, decreasing from 8.86% to 8.34%, weight decreased from 84.78 kg to 83.88 kg and diastolic blood pressure decreased from 75.40 mm Hg to 72.40 mm Hg. Mean waist circumference of the participants improved from average mean 107.40 cm to 105.88 cm. Goals included the following: quitting or reducing the number of cigarettes per day, choosing healthy food, exercise, reducing weight, and monitoring glucose levels. At the end of the three months period, participants demonstrated clear achievements of goals set. For a feasibility study, the information gathered was valuable for developing future studies in this area. Results from this study indicate that a pharmacist-led diabetes education addressing the spiritual, cultural, lifestyle and educational needs of Arabic speaking people with diabetes when successfully implemented has the potential to improve health related outcomes. In summary, participants in this research did have clear improvements in clinical measures following the intervention. © 2015 DAR Publishers/The University of Jordan. All Rights Reserved.

Perera V.,University of Sydney | Perera V.,Center for Research and Education on Ageing | Gross A.S.,University of Sydney | Gross A.S.,Glaxosmithkline | And 2 more authors.
Current Drug Metabolism | Year: 2012

The drug metabolising enzyme CYP1A2 contributes to the metabolism of a number of medicines including clozapine, olanzapine and theophylline. These medicines display a high degree of inter-individual variability in pharmacokinetics and response. Measuring CYP1A2 activity in vivo can be an important tool to identify the factors that influence variability in drug pharmacokinetics and inform dose selection. Caffeine is the only currently accepted probe to conduct in vivo phenotyping of CYP1A2. Despite the number of proposed matrices (biological fluid containing the drug and/or metabolite/s of interest) and metrics (mathematical formula relating the drug and/or metabolite/s to enzyme activity) proposed to measure CYP1A2 activity using caffeine, many of these are compromised by factors related to the specific metabolic pathway studied or pharmacokinetic characteristics of caffeine and its metabolites. Furthermore, questions regarding the appropriate study design and methodology to conduct studies to evaluate CYP1A2 activity have often been overlooked. These issues include the potential influence of a methylxanthine abstinence period prior to caffeine CYP1A2 phenotyping and the impact of caffeine formulation on determining CYP1A2 activity. This review aims to discuss the various CYP1A2 matrices and metrics with a particular focus on unresolved methodological issues. © 2012 Bentham Science Publishers.

Perera V.,University of Sydney | Perera V.,Center for Research and Education on Ageing | Gross A.S.,University of Sydney | Gross A.S.,Glaxosmithkline | And 2 more authors.
Biomedical Chromatography | Year: 2010

Caffeine has been extensively used as a probe to measure CYP1A2 activity in humans with caffeine clearance or the paraxanthine (major metabolite of caffeine) to caffeine concentration ratio being regarded as the preferred metric. A simple reverse-phased C18 HPLC assay using ethyl acetate liquid-liquid extraction was developed to quantitate caffeine and paraxanthine concentrations in saliva and plasma. The mobile phase consisted of acetonitrile-acetic acid-H2O (100:1:899) and analytes were quantitated with UV detection at 280 nm. The extraction recovery for paraxanthine and caffeine was approximately 70% in both saliva and plasma. The assay was linear over the concentration ranges 0.05-2.50 and 0.05-5.00 μg/mL, for paraxanthine and caffeine, respectively, in saliva. In plasma the assay was linear over the ranges 0.025-2.50 and 0.025-5.00 μg/mL for paraxanthine and caffeine, respectively. Intra- and inter-assay precision and accuracy were less than 15%. Detection limits were 0.015 μg/mL for paraxanthine and caffeine in saliva, while it was 0.005 μg/mL for paraxanthine and caffeine in plasma. Utility was established in samples collected from two healthy volunteers who abstained from caffeine for 24 h and received a single 100 mg oral dose of caffeine. The assay developed is a robust, simple and precise technique to measure caffeine and paraxanthine in saliva and plasma of healthy volunteers after a single oral dose of caffeine. Copyright © 2010 John Wiley & Sons, Ltd.

Perera V.,University of Sydney | Perera V.,Center for Research and Education on Ageing | Gross A.S.,University of Sydney | Gross A.S.,Glaxosmithkline | And 2 more authors.
Clinical Pharmacology and Therapeutics | Year: 2012

The drug-metabolizing enzyme CYP1A2 contributes to the metabolism of a number of commonly used medicines and displays wide interindividual variability. The aim of this study was to investigate CYP1A2 activity in a population of South Asian ancestry and compare it with a population of European ancestry. CYP1A2 activity was determined using the 4 h paraxanthine/caffeine saliva concentration ratio following a 100-mg oral dose of caffeine in healthy individuals of South Asian (n = 166) and European (n = 166) ancestry. Participants were surveyed for extrinsic ethnic factors and genotyped for polymorphisms in CYP1A2 and related genes. Significantly lower CYP1A2 activity was observed in South Asian participants (median: 0.42; range: 0.10-1.06) as compared with European participants (0.54; 0.12-1.64) (P 0.01). Multiple linear regression indicated that 41% of the variability in CYP1A2 activity could be explained by the diet, lifestyle, and genetic factors studied. © 2012 American Society for Clinical Pharmacology and Therapeutics.

Discover hidden collaborations