Objective:  to understand how the change in each of the pharmacokinectic parameters affects the overall drug concentration-time profile.

a-  choose a value for each of the pharmacokinetic parameters, and simulate the drug concentration-time profile.

b-  Try to predict the change in the drug concentration-time profile due to the increase or decrease in the value of each of the parameters.

c-  Simulate the drug-concentration-time profile and compare the results with your prediction.

Objective:  to be able to design a dosing regimen (dose and dosing interval) to achieve therapeutic drug concentration at steady state.

Theophylline is a drug used in the treatment of asthma. The average half life of theophylline is 6 hr and the average Vd is 0.5 L/kg. The therapeutic range of theophylline is 10-20 mg/L.

a-  Recommend an appropriate dosing regimen for a 60-kg patient to achieve drug concentrations within the therapeutic range at steady state.

b-  Using the dosing regimen you recommended, simulate the drug concentration-time profile and assess your recommendation.

Objective:  to be able to design a dosing regimens in conditions that affect the durg disposition rate.

The average half life of theoplhylline is 6 hr and Vd is 0.5 L/kg. The therapeutic range of theophylline is 10-20 mg/L.

Smokers are known to have faster rate of theophylline elimination. The average theophylline half life in smokers is 4 hr and Vd is 0.5 L/kg.

a-  Recommend an appropriate dosing regimen for a 60-kg adult smoker to achieve drug concentrations within the therapeutic range at steady state.

b-  What will be the steady state theophylline concentrations if the dose you reommended for the smoker patient was given to a nonsmoker (k=0.1 hr). Use the plotting function to simulate the plasma concentration-time profile and assess your answers. Repeat the simulation as many times as you wish.

Objective:  to be able to design appropriate dosing regimens in conditions that affect the durg disposition rate.

The average half life of theoplhylline is 6 hr and the average Vd is 0.5 L/kg. The therapeutic range of theophylline is 10-20 mg/L.

Cimetidine is a drug known to significantly slow the rate of the theoplhylline elimination. The average theophylline half life in patients receiving cimetidine is 10 hr, and the average Vd is 0.5 L/kg.

a-  Recommend an appropriate dosing regimen for a 60-kg adult who to achieve drug concentrations within the therapeutic range at steady state.

b-  Predict what will happen in theophylline steady state concentrations if the patient started talking cimetidine. Use the plotting function to simulate the plasma concentration-time profile and assess your answers. Repeat the simulation as many times as you wish.

Objective:  to be able to design appropriate oral dosing regimens.

Theophylline is a drug used in the treatment of asthma. Its average half life is 6 hr and its average Vd is 0.5 L/kg. The therapeutic range of theophylline is 10-20 mg/L.

a-  A 60-kg patient is receiving 45 mg/hr theophylline as a constant rate iv infusion to control an acute attack of bronchial asthma. Because the patient condition is controlled, you were asked to recommend an appropriate oral dosing regimen for this patient.

Use the plotting function to simulate the plasma concentration-time profile and assess your answers. Repeat the simulation as many times as you wish.

Objective:  to be able to evaluate the dosing regimens in patients.

The average half life of theophylline is 6 hr and the average Vd is 0.5 L/kg. The therapeutic range of theophylline is 10-20 mg/L.

A 60-kg patient is receiving 600 mg theophylline fast-release tabley every 12 hours. The patients is complaining from nausea and comiting which are the main theophylline side effects.

a-  Evaluate the appropriateness of this dosing regimen this patient.

b-  Recommend an appropriate change in patient dosing regimen to eliminate the patients's complain.

Use the plotting function to simulate the plasma concentration-time profile and assess your answers. Repeat the simulation as many times as you wish.

Objective:  to be able to evaluate dosing regimens specific patient populations.

The average half life of theophylline in adults is 6 hr and the average Vd is 0.5 L/kg. The therapeutic range of theophylline is 10-20 mg/L. children are known to eliminate theophylline faster than adults. The average half life in children is 4 hr and the average Vd is 0.5 L/kg.

a-  A 30-kg child is receiving 200 mg theophylline every 8 hours. Evaluate the appropriateness of this dosing regimen in this child.

b-  Recommend an appropriate dose of theophylline to be given every 12 hours to acheve theophylline concentrations within the therapeutic range at steady state.

Use the plotting function to simulate the plasma concentration-time profile and assess your answers. Repeat the simulation as many times as you wish.

Dose : The administered dose, mg

F : The drug bioavailability, no units

Dosing interval : The time between doses, hours

ka : The first order absorption rate constant, hour-1

Vd : The vloume of distribution, liters

k : The first order elimination rate constant, hour-1

Dose : The administered dose, mg

F : The drug bioavailability, no units

Dosing interval : The time between doses, hours

ka : The first order absorption rate constant, hour-1

Vd : The vloume of distribution, liters

k : The first order elimination rate constant, hour-1

Select values for the half-life by dragging the slider for the half-life to the right. The selected value for the half-life will be displayed.

The drug amount-time profile will be plotted when you click plot.

Enter the maximum value for the X axis. The minimum value for the X axis will be zero.

Enter the maximum value for the Y axis. The minimum value for the Y axis will be 1/1000 of the maximum value.