Module 3.5: OneCompartDilantin

If the above applet fails to run you can launch Nova using Java Web Start.

To run this model on your version of Nova click here to download and save its file.

This model shows the concentration of the drug Dilantin, a drug for epilepsy, that patients take on a regular basis. The stock, drug in system, represents the initial mass of Dilantin in the body, which is 0. The flow, ingested, represents the does of the drug that is ingested. This model uses a pulse function to represent the periodic nature of dosage. The pulse function looks like this in the ingested flow: Pulse(doseage,start,interval) where dosage, start and interval are all terms. The pulse function is multiplied by an absorption fraction of .08. The ingested flow then goes into the drug in the system stock.

The pink term for concentration is the amount of the stock, drug in the system/volume. The graph and the table represent concentration over time. Volume is a term with the value 2000.

The elimination flow is proportionate to drug in system * elimination constant. The elimination constant is similar to the elimination constant in the OneCompartAspirin model. Elimination constant = -Math.log(.5)/half_life. The half-life is 22 hours.

This model has terms for minimum effective concentration (MEC) and minimum toxic concentration (MIC) for comparison purposes.