Background and objectives: The T-optimality criterion for model discrimination was introduced by Atkinson and Fedorov [1]. Application of this method required the condition that one of the competing models is correct. We term this criterion local T-optimality. In addition, T-optimal designs are generally not efficient for parameter estimation. The aims of current work are (1) to […]
Pavan Vajjah
- School of Pharmacy, University of Otago
Author Archive | Pavan Vajjah
Pharmacodynamics of venlafaxine in overdose
January 5, 2010
Authors Venkata Pavan Kumar Vajjah (1), Geoffery K Isbister (2,3), Stephen B Duffull (1)
Affiliations (1) School of Pharmacy, University of Otago, Dunedin, New Zealand, (2) Department of Clinical Toxicology and Pharmacology, Newcastle Mater Hospital, Newcastle, Australia, (3) Tropical Toxinology Unit, Menzies School of Health Research, Charles Darwin University, Darwin, Australia
Presentation type Oral
Background: Venlafaxine, a serotonin-noradrenalin reuptake inhibitor, appears to be more toxic in overdose than other newer antidepressants. Various studies have shown that there is an increased risk of seizures [1], a potential for cardiac toxicity [2] and a higher rate of fatalities [3] with venlafaxine overdose when compared to other antidepressants. A population pharmacokinetic (PK) analysis […]
Novel diagnostics for assessing fit of logistic regression models
January 13, 2009
Authors Venkata V Pavan Kumar, Stephen B Duffull
Affiliations School of Pharmacy, University of Otago, Dunedin, New Zealand
Presentation type Oral
Background: Assessment of goodness of fit of a model to the data set is essential to ensure the model provides a reasonable description of the events seen. For logistic regression the most common diagnostic used for this purpose is binning the data and comparing the empirical probability of an event in each bin to the model […]
What to do about missing dosage history?
January 10, 2008
Authors Kumar VVP, Duffull SB
Affiliations Modelling and Simulation Lab, School of Pharmacy, University of Otago, Dunedin, New Zealand
Presentation type Oral
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 […]