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Flashcards in Drug Absorption Deck (23)
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1
Q

correct pharmacological effect - effect of drug on the body

A

Pharmacodynamic

2
Q

drug to site of action
what your body does to the drug?
how removed?
ADME

A

Pharmacokinetic

3
Q

drug into patient

A

Pharmaceutical

4
Q

The time to peak concentration

A

(Tmax)

The more rapid the rate of absorption, the earlier the drug concentration peak.

5
Q

The peak concentration

A

(Cmax)

Increasing dose does not reduce the time at which peak concentration is reached but does increase the peak concentration

6
Q

Total exposure to drug; amount of drug reaching systemic circulation

A

AUC

The area under the drug concentration-time curve represents the amount of drug which reaches the systemic circulation.

7
Q

measure of the range at which a drug is safe and active

A

therapeutic index

Index lower - oral - plasma conc low - compared to other route of administration

8
Q

drug is active over a range of concentrations

A

therapeutic range

9
Q

A drug given _________ has 100% bioavailability.

A

intravenously

10
Q

Factors affecting bioavailability (oral) - list 5

A
Formulation
Ability of drug to pass physiological barriers/transport across memb- Particle size, Lipid solubility, pH and ionisation (unionised - cross lipid but do not dissolve in H20 / ionised cannot cross memb
GI effects
First pass metabolism
Slow release preparations
11
Q

Does ionised drug cross the membrane?

A

No.

Most drugs are weak acids or bases; the degree of ionisation depends on the pH of the environment.

Most drugs do not completely ionise in water.

12
Q

The ability of a drug to diffuse across a lipid barrier

A

a lipid-water partition coefficient.

This is the ratio of the amount of drug which dissolves in the lipid and water phase when they are in contact.

13
Q

To pass across a lipid layer a drug must be in solution and ________ soluble.

A

lipid

A drug that is not lipid soluble may not be absorbed at all, for example gentamicin.

14
Q

To undergo active transport drugs must resemble ______

A

naturally occurring compounds.

15
Q

____________occurs through inter-cellular pores and is the major mechanism through which drugs cross the capillary walls.

A

Filtration

normal method for water soluble molecules with a molecular weight of 100 or less.

16
Q

Metabolism of drug (gut –> liver) prior to reaching systemic circulation

A

First Pass metabolism

17
Q

Which drug administration avoids first pass metabolism?

A

IM, Sublingual, subcutaneuous, rectal,buccal, transdermal

18
Q

Which drug administration undergoes first pass metabolism?

A

oral

19
Q

Relation between local pH and degree of Ionisation
Henderson-Hasselbach
ion trapping

A

Diffusion-Ionisation

20
Q

conc of ionised = unionised same

A

pH = pKa

21
Q

Sublingual (SL)

A

under tongue

bypass first met

22
Q

buccal

A

cheek - inside mouth

23
Q

Despite route of administration, same dosage of drug = same AUC = same half life - T or F?

A

True