2- Fundamentals behind drug regimes

Question 1

Define loading dose

Answer 1

Initial high dose used to elevate the level of the drug in the blood quickly

Enables to reach steady state conc quicker

Determined by volume of distribution

Question 2

Define maintenance dose

Answer 2

Dose needed to only replace amount of drug lost through metabolism and excretion

Equal to clearance

Question 3

List 4 factors of a drug which are ideal in respect to its potency, absorption, bioavailability & distribution.

Answer 3

High potency ideal
Lipophilic to be absorbed across the plasma membrane
Metabolised at a reasonable rate (too quick - no desired effect)
Tightly bound to plasma proteins

Question 4

What is the steady state of a drug?

Answer 4

The point at which the amount of drug being administered equals the amount being eliminated

Normally achieved within 5 half life

Question 5

Increasing dosage frequency of a drug results in…

Answer 5

Reduces peaks and troughs and approaches steady state concentration

Question 6

Can drugs bound to plasma proteins be distributed, metabolised and excreted?

Answer 6

No needs to be free

Question 7

How does extensive protein binding affect drug elimination?

Answer 7

Slows