Multiple dosing regimen and Double regimen design Review

Question 1

What is infusion?

Answer 1

Infusion involves a continuous administration of a drug at a constant rate.

Question 2

What does multiple dosing look like?

Answer 2

Multiple dosing involves intermittent administration of doses at set intervals.

Question 3

Does both infusion and multiple dosing result in drug accumulation?

Answer 3

Drug accumulation occurs differently in both methods, with multiple dosing leading to fluctuations in drug concentration.

Question 4

What is Rac?

Answer 4

Accumulation Index (Rac) describes how much the drug accumulates over repeated doses.

Question 5

At what concentration do the number of doses approach infinity?

Answer 5

Steady state (SS)

Question 6

What factors influence accumulation?

Answer 6

Less frequent dosing (i.e., larger dosing interval τ) leads to lower accumulation.

The larger the dosing interval (τ), the less accumulation occurs.

Question 7

What is fluctuation in drug concentration?

Answer 7

Fluctuation refers to the variability in drug concentration between the peak (Cmax) and trough (Cmin) within a dosing interval.

Question 8

What factors influence drug fluctuation?

Answer 8

A larger dosing interval (τ) leads to greater fluctuation.

More frequent dosing reduces fluctuation.

Question 9

What is the relationshop between fluctuation and accumulation?

Answer 9

More frequent drug administration results in smaller fluctuation.

More frequent dosing leads to greater accumulation.

Question 10

T or F: A higher dose does not necessarily result in greater drug accumulation.

Answer 10

true

Question 11

What is Css avg?

Answer 11

The same amount of dose per unit time will result in the same average steady-state concentration (Css avg).

Css avg is the concentration that gives the same Area Under Curve (AUC) as multiple dosing when maintained for τ.

Question 12

What are the 5 steps we follow to determine the dosing regimen design?

Answer 12

1. Determine Target Concentration Range: Identify the desired therapeutic window.
2. Set Maximum Dosing Interval (τ max): Choose a practical interval (e.g., q6h, q8h, q12h, or once daily).
3. Calculate Maintenance Dose (DM): Select a dose ensuring Css avg remains in the middle of the target range.
4. Verify Css max and Css min: Ensure they fall within the expected therapeutic range. Adjust dose or τ if needed.
5. Calculate Loading Dose (DL), if necessary: Used when immediate therapeutic levels are required.

Question 13

What is τ?

Answer 13

The dosing interval