Vidya Perera

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AIM Develop a measure of frailty for older acute inpatients to be performed by non-geriatricians. METHOD The Reported Edmonton Frail Scale (REFS) was adapted from the Edmonton Frail Scale for use with Australian acute inpatients. With acute patients aged over 70 years admitted to an Australian teaching hospital, we validated REFS against the(More)
OBJECTIVES To investigate the utility of metrics of CYP1A2 activity using caffeine as a probe, and saliva and plasma sampling with or without a 24-h caffeine abstinence. METHODS This was a cross-over pharmacokinetic study in 30 healthy male subjects who received a single oral 100mg caffeine dose after 24-h caffeine abstinence or after maintaining their(More)
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(More)
OBJECTIVE to investigate the impact of frailty on the utilisation of antithrombotics and on clinical outcomes in older people with atrial fibrillation (AF). DESIGN prospective study of a cohort of 220 acute inpatients aged > or =70 years with AF, admitted to a teaching hospital in Sydney, Australia (April-July 2007), with 207 followed up over 6 months. (More)
This study aimed to investigate the impact of methylxanthine abstinence (MA) periods on CYP1A2 activity in individuals with varying levels of caffeine consumption through development of a population pharmacokinetic model of caffeine and its major metabolite paraxanthine. This study developed and evaluated a mixed-effects pharmacokinetic model for caffeine(More)
INTRODUCTION Schizophrenia, a mental disorder, is a debilitating condition which typically strikes young people in their early 20's. Antipsychotic medications are widely prescribed for the treatment of schizophrenia however a balancing act is necessary to provide the correct dose to each patient. It is suggested that a large number of patients discontinue(More)
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 C(18) HPLC assay using ethyl acetate liquid-liquid extraction was developed to quantitate caffeine and(More)
OBJECTIVES Response to some medications can depend on time of administration throughout the day. This study investigated diurnal variation in cytochrome P450 1A2 (CYP1A2) activity in people of South Asian and European ancestry. METHODS CYP1A2 activity was determined using the 4-h paraxanthine/caffeine saliva concentration ratio following a 100-mg oral(More)
Terbinafine is increasingly used in combination with other antifungal agents to treat resistant or refractory mycoses due to synergistic in vitro antifungal activity; high doses are commonly used, but limited data are available on systemic exposure, and no assessment of pharmacodynamic target attainment has been made. Using a physiologically based(More)
The fast-growing consumption of caffeinated energy drinks (CEDs) is linked to increasing reports of caffeine intoxication in adolescents. There is limited data available regarding plasma caffeine concentrations in this population after CED intake and the potential implications for caffeine-related toxicity. This study was an in silico population(More)