Abstracts

Background: Clinicians have observed longer awakening times for obese compared to normal-weight patients when propofol is dosed as per label guidelines on Total Body Weight (TBW).  This may be explained by the non-linear relationship between TBW and CL described by Schuttler et al1.  Lean Body Weight (LBW) has been reported to have a linear relationship with […]

Objectives: Evaluation of the currently used amikacin dosing regimen in neonates and proposal of an optimal pharmacokinetic (PK) and pharmacodynamic (PD) amikacin dosing regimen. Methods: A retrospective chart review was performed including all neonates treated with amikacin at Dunedin Hospital from Oct 2003 to Jan 2007. The population PK analysis included all the study subjects […]

Background: Diabetes is a major health risk in many countries and incidence rates are increasing. Diverse anti-diabetic agents act through various mechanisms on different organs. A large array of mathematical models has been proposed to describe anti-diabetic drug effects. Objectives: 1) To systematically compare structural models that were used to model anti-diabetic drug effects. 2) To […]

Combination therapies are becoming increasingly common and are standard practice in anesthesia and oncology.  This talk focuses on studies most relevant to anesthesia where it is of interest to describe the pharmacodynamic effect of two drugs given simultaneously.  This effect is generally described via a response surface where parameters exist nonlinearly in the model and […]

Background: An inaccurate or missing dose history (MDH) is one of the major obstacles in determining unbiased estimates of the pharmacokinetic (PK) parameters of a drug in clinical practice.  This is particularly the case with drug overdose when the patient may either not recall the events or choose not to provide an accurate history. Methods have […]

Background: Acyclovir exhibits a selective inhibition of herpes virus replication with potent clinical antiviral activity against the herpes simplex and varicella-zoster virus (King & Madera, 1988).Valacyclovir, a pro-drug of acyclovir, increases the oral bioavailability of acyclovir (Soul-Lawton et al. 1995). Acyclovir is primarily renally eliminated. Acyclovir displays variability in treatment response which supports the need for individualised dose […]

Many situations exist where multiple responses are measured during an experiment, e.g. parent and drug metabolite concentration and drug toxicity and efficacy. Typically the responses will be mixed (continuous and discrete) and display varying dependence structures. When standard multivariate distributions do not exist or are not applicable, a more flexible approach to the construction of […]

Background: Determination of optimal doses for obese patients is challenging due to the paucity of clear dosing guidelines for this population. Empirical dosing strategies based on total body weight (WT) may result in overdoses in the obese, whereas arbitrary dose capping by physicians may produce sub-therapeutic concentrations. Quantifying the impact of obesity on drug clearance using […]

Background: High dose melphalan is standard conditioning for autologous stem cell transplantation in the treatment of multiple myeloma. Appropriate dosing is critical as melphalan may be associated with profound toxicity, including cytopenia and gastrointestinal toxicity, which can lead to significant treatment-related mortality, while insufficient dose intensity can lead to disease relapse. The aim of this study was […]

Background: Missing data due to subject dropout from study is common in late phase clinical trials. It is possible for missing to be equivalent to lost and has no relevance to time course of the data. On the other hand, circumstances exist where compelling reasons could be formed to argue that dropout is related to underlying […]