Transcript Valproic Acid - Dr Ted Williams

Valproic Acid
Software and Presentation by:
Ted, Rob, Jeff, Cassie, Tristan, Korin,
Ron, Gabe, Matt, Judith, Lindsay
General Information
Used in the management of multiple
seizure types.
 Oral and IV forms
 Also indicated for management of bipolar
affective disorder and possible migraine
prevention.
 Increases body’s production and response
to GABA.
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Therapeutic / Toxic Conc’s
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Cpss range- 50 to 100 mcg/ml.
Upper limit of 175mcg/ml with proper monitoring.
At concentrations >75 mcg/ml some patients
may experience adverse effects.
Basic Clinical Pharmacokinetics
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Exhibits concentration dependant protein
binding
Follows Non-Linear Kinetics
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Highly protein bound to albumin
Follows a basic 1-Compartment Model.
Clinical Implications
Clearance is now dose or concentration
dependant.
 Volume of Distribution is now affected by
concentration-dependant plasma protein
binding and its value should be 0.15 to 2.0
L/kg.
 Half Life 12 to 18 hrs for adults and is
found by the eqn. t1/2=0.693xVd/Cl
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Software Structure
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Functional
components of the
software were
segmented into
“tiers” to make the
application to
support ease of
use and
maintainability
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Core
Peripheral
Variable
Core
Core Components
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Contains foundational
assumptions of the
software
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User Input requirements
Kinetic Models
Changing the Core will
cause global changes
to functionality and
require massive
reworking of the
system
Intolerant to changes
Core
Peripheral Components
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Contains slowly
changing parameters
Changes cascade to
most sections of the
software
Changes tolerated, but
should be rare and
hidden from most
users
Provides extensibility
of the application
Includes reports
charts, kinetic
parameters
Core
Variable Components
Continuously
changing
 High tolerance to
changes, incorrect
/ inappropriate
input
 Patient Cases
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Core
Bayesian Pharmacokinetics
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Estimate drug dosage or steady state
plasma concentration
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Patient’s parameters (age, weight, sex, serum
creatine)
Absence of or with measured drug levels
DrugCalc shareware software
Dr. Dennis Mungall
 Nonlinear regression
 One-compartment model
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DrugCalc Example
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Enter patient’s demographic,
drug dosing, and serum
concentration
Compute the pharmacokinetic
parameters
Compute desired dose to
achieve steady state
concentration
Example time