Pill Dosing Simulation

• Click the ‘Sign In’ tab above to login with your UF credentials OR to create a free account.
• Read the "Simulation and Context" information below.
• Click the ‘Launch Content’ button below to open the simulation.
• Access the scenario instructions by clicking the arrow in the "Scenarios" section below.
• When you are finished with the course content, click the button to take the Post-Test.

Non-compliance with prescribed drug regimens is a major identified health literacy issue that affects the quality of life and health of the nation as well as healthcare costs. As one example of many, poor compliance with taking medication as per the schedule that is prescribed is considered an important, if not the most significant, contributing factor in rejection of an organ transplant. Non-compliance includes:

1) forgetting/skipping a dose
2) taking less (e.g., half) of the prescribed dose at the prescribed interval
3) taking the prescribed dose at intervals longer than the prescribed interval
4) taking twice the dose at the next interval after missing the previous dose

Some degree of non-compliance with taking medications as prescribed ranges from one in every three people to more than half of all patients in some studies.

Two important concepts are the Minimum Effective Concentration (MEC) and the Minimum Toxic Concentration (MTC). The Minimum Effective Concentration (aka the Minimum Therapeutic Concentration) is the lowest drug concentration that will produce the desired drug effect (pharmacological effect).  The Minimum Toxic Concentration is the lowest drug concentration that can cause a harmful effect. 

This simulation addresses health literacy and patient education. The visualization of the effects of compliance and non-compliance with a prescribed drug regimen, through a web-enabled, intuitive, and user-friendly interface, may help promote improved compliance with prescribed drug regimens.

Using the simulation:

Left click and drag the pills on the timeline to the pill box to remove or modify a dose. To add pills to the timeline, left click and drag pills from the pill box to the desired time or dose on the time axis

Click the arrow to the left to expand the section below.

Steps:

 Understanding the rationale behind the prescribed dosing interval

1. Start the simulation
2. Use the default settings of the simulation
3. The horizontal x- axis is time
4. The vertical y-axis is the drug concentration in the body
5. The green horizontal line is the Minimum Effective Concentration (MEC), the minimum concentration needed for the drug to produce the desired therapeutic effect
6. The thick red horizontal line in the upper part of the graph is the Minimum Toxic Concentration (MTC), the concentration at which toxicity or undesired side effects start to appear 
7. The space between the MEC (horizontal green line) and the MTC (horizontal thick red line) is the therapeutic window. We want the drug concentration to stay within the therapeutic window at all times if possible
8. The thin red trace shows the drug concentration in your body over time. For the purposes of this patient education course, the blue trace can be ignored
9. The drug concentration (red trace) rises sharply upon taking the first set of pills at time 0
10. The drug concentration then starts tapering down after the first dose from the initial peak over time as the body breaks down the drug.
11. The second dose is taken before the drug concentration falls below the green line (the MEC) to maintain the drug concentration within the therapeutic window
12. The peak of the second dose is higher than the first peak because there is still residual drug in the body from the first dose when the second dose was taken. The higher peak stays within the therapeutic window and does not cross the thick red line (the MTC)
13. Increase the time interval from the default of 12 h to 24 h by clicking and dragging the slider button on the Dose interval (h) slider
14. The drug concentration dips below the green line (MEC) at a 24 h dosing interval, meaning that the desired effect of the drug is not being continuously provided

Scenario notes:
The prescribed dosing interval of a prescription is chosen to continuously maintain the drug concentration within the therapeutic window so that the benefits of the drug are provided without interruption




 

   

Click the arrow to the left to expand the section below.

Steps:

1.      Restart the simulation (close the window and click "Launch Content")
2.      Simulate taking only half of the prescribed dose: Take away one of the pills for all four doses by clicking and dragging one pill in each dose back into the pill box
3.      The drug concentration dips below the green line, the MEC. The desired effect of the drug is no longer continuous when the drug concentration strays from the therapeutic window

Scenario notes: Reducing the prescribed dose (e.g., to save on cost or make your pill supply last longer) runs the risk of the drug concentration not remaining within the therapeutic window. Ensure patients understand that they should adhere to the prescribed dose at the prescribed dosing interval, unless advised differently by their prescriber.

Click the arrow to the left to expand the section below.

 Steps: 

1. Restart the simulation (close the window and click "Launch Content")

2. Remove both pills from the second dose to simulate forgetting to take a dose and observe the drug concentration

3. Add 2 pills to the next dose to “make up” for the missed dose and notice how the drug concentration does not stay within the therapeutic window and overshoots past the thick red line (the MTC)

Scenario notes: “Making up” for a forgotten dose by adding it to the dose at the next dosing interval runs the risk of the drug concentration overshooting past the MTC, depending on the patient and the width of the drug’s therapeutic window. The tighter the therapeutic window, the harder it is to keep the drug concentration within the therapeutic window unless the doses are taken at the prescribed interval. Ensure patients understand that they should not take a double dose to make up for a missed dose, unless advised by their prescriber