Multiple Dosing lecture 2

Question 1

Caverage is not a simple mathematical average of Cmax and Cmean. There is an equation for calculating the Caverage. Normally is basically denoted as C and the bar on the top is Caverage

Question 2

When multiple drug doses are given, drug accumulates in the body: the half of the drug to dosing interval is longer

Question 3

When multiple drug doses are given and steady state is reached, the amount of drug eliminated during one dosing interval is equal to the drug dose

Input=output

Question 4

Time to reach steady state solely depends on the half life of the drug…here we have 2 drug profile which is Profile A and Profile B

Question 5

Between Drug A and Drug B which reaches to steady state faster

Question 6

If I want to calculate the time to reach steady state its going to be 4 x t1/2 so therefore time to reach to steady state for Drug A is shorter compared to Drug B because the t1/2 is ________

Answer 6

shorter

Question 7

4 x shorter value is going to be less compared to the value for B. Now if you have two drug candidates that similar efficacy and everything but A has a shorter half life compared to B then your goal is to achieve faster steady state which candidate is going to go to the pipeline for development…it would be drug A

Question 8

These are some characteristics of multiple drug IV bolus…the dose is fixed through the dosing regimen so if you start for example 100mg your going to continue that unless otherwise we have a new scenario but the assumption is that the dose is fixed and the interval is also fixed so like every 12 hours or every 8 hours

Our assumption is one compartment open model first order elimination…these are the assumptions that we are going to have and based on that we are going to look at our equations

Question 9

Multiple drug regimens characterization

Second dose administered before the first dose is completely eliminated

Question 10

If I want to calculate Cmax1 what is the equation. What is the equation to calculate Cmax1? Dose/Vd

Question 11

____________ is a very useful factor it tells a lot after certain amount of dose or steady state how much concentration is going to be increased…how many folds the concentration is going to be increased…this important to know safety index of the drug….you know the minimum effective concentration…minimum toxic concentration…you want to make sure that Cmax and Cmin is going to be in safe ranges so you can simply use your first done maximum and minimum concentration and multiply that by your accumulation factor to determine if its within the range or not

Answer 11

accumulation factor