An Updated Comparison of Drug Dosing Methods

Abstract

The relationship between a dose of phenytoin and the resultant serum concentration is difficult to predict, and numerous dosing methods have been developed to quantify the dose required to achieve a specific concentration. This review brings up to date the earlier article in the Journal regarding predictive algorithms, various pharmacokinetics-based dosing techniques and Bayesian feedback methods for phenytoin dosing. The latest data support the original conclusions that dosing methods for phenytoin which incorporate an individualised approach or Bayesian principles tend to offer results superior to those from predictive algorithms. Bayesian methods have the additional advantage of using only 1 serum concentration, obtained under either steady-state or non-steady-state conditions. There is still a need for future investigations that include prospective evaluations of predictive performance and cost-effectiveness data.

Estimation of Phenytoin Pharmacokinetic Parameters in Saudi Epileptic Patients

“…It displays a nonlinear pharmacokinetics behavior at therapeutic concentrations [15]. It has a dose-dependent clearance and its half-life is affected by the limited metabolic capacity, which may result in a disproportional relationship between serum concentration and administered dose [16]. These factors greatly complicate the use of phenytoin and require close monitoring.…”

Practical, Individualized Dosing: 21st Century Therapeutics and the Clinical Pharmacometrician

“…Numerous nomograms and formulas have been designed to estimate the correct dose of vancomycin 14 , 15 . None of them were designed to achieve target trough concentrations of 15 to 20 mg/L, which highlights a general limitation of this approach: lack of flexibility.…”

Structure-Binding Relationships for the Interaction between a Vancomycin Monoclonal Antibody Fab Fragment and a Library of Vancomycin Analogues and Tracers

“…To further verify that the peptide and antibodybinding pockets of vancomycin were mutually exclusive, the vancomycin/anti-vancomycin Fab fragment solution binding interaction was reinvestigated under the conditions described above in the presence of (N a ,N -diacetyl)-KdAdA tripeptide (500 µM). The K D value obtained for the vancomycin/anti-vancomycin Fab fragment binding interaction in solution in the presence of (N a ,N -diacetyl)- (6) 42 000 ( 1000 N-acetylvancosaminylvancomycin (7) e0.2 b ring-2 dechlorovancomycin (8) 8 7 ( 4 carboxyl-HDAvancomycin (9) 0.32 ( 0.04 CDP (10) 488 ( 34 AglucoCDP (11) g50 000 c ring-2 dechloroCDP (12) 6000 ( 100 a Values are average equilibrium dissociation constants obtained from triplicate measurements. b KD was too small to be reliably measured by solution affinity experiments.…”

“…It is also the treatment of choice in bacterial infections in patients allergic to β-lactam antibiotics (10). For the safe and effective use of this drug, quantitation of its levels in patient blood is required to maintain therapeutic levels (11,12). Immunoassay techniques requiring structurally modified vancomycin tracers are frequently employed for this purpose.…”