Behavioural Pharmacology

Question 1

In the brain which areas of the blood/brain barrier are weaker?

Answer 1

Pineal Gland, Choroid Plexus and Median Emminence of the Hypothalamus.

Question 2

Define Pharmacodynamics.

Answer 2

The study of how a drug influences processes within the organism, from the most molecular levels to the functional levels,

Question 3

Define Pharmacokinetics.

Answer 3

The study of how the drug is removed from an organism and tries to answer questions like: Is the drug metabolized or simply excreted? How long does the drug stay in the body?

Question 4

What is the relationship between drug action and effect?

Answer 4

Drug action is the specific molecular changes produced by a drug which lead to drug effects, or alterations in physiological or psychological function.

Question 5

What are the steps in the process of drug action?

Answer 5

1. Drug administration, Absorption and distribution, binding, inactivation and excretion.

Question 6

What is I.V.?

Answer 6

Intravenous Administration. This is direct to the blood and is fast so leaves little time for correction. Highly skilled people administer drugs this way for this reason, and because you need to know exactly which drugs to administer and the effect they will have, etc.

Question 7

What is I.M.?

Answer 7

Intramuscular Administration. Slower than I.V. 10-30 minutes, can be done in vegetable oil to make even slower.

Question 8

What is S.C.?

Answer 8

Subcutaneous Administration. Injected directly under the skin, where it is absorbed by blood vessels. Rate of absorption varies from person to person.

Question 9

What is I.P.?

Answer 9

Intraperitoneal Administration. Common in animals, The peritoneum lines the abdominal cavity, when injected with the drug it is absorbed through the blood vessels.

Question 10

What is P.O.?

Answer 10

Oral Administration. Done with drugs that dissolve in the stomach, are resistant to acid degradation, and can pass through the stomach wall to reach blood capillaries.

Question 11

Regarding absorption of the drug, what determines the rate and extent?

Answer 11

1. Individual differences like gender, the health of the blood/brain barrier, fat to water ratio. Fat to water ratio – Drugs move through the layers from the site of administration to the blood.
2. Drug differences.

Question 12

What determines whether a drug can pass through the membrane via passive diffusion?

Answer 12

• Molecular shape and weight.
• Lipid solubility.
• Degree of ionization. Electrically charged molecules are very hydrophilic, so pass through the lipid bilayer slowly.

Question 13

What is the oil/water coefficient?

Answer 13

The ratio of fat to water

Question 14

Do lipophilic/hydrophobic drugs have a high oil/water coefficient?

Answer 14

Yes.

Question 15

Are electrically charged molecules hydrophobic or hydrophilic?

Answer 15

Very hydrophilic.

Question 16

What is morphines’ singular drug action?

Answer 16

Stimulation of μ-opioid receptors. These are in many different places in the brain, hence why morphine has many effects. Example of a metabotropic receptor.

Question 17

What does the classical theory by Clark and Gaddum state?

Answer 17

That your body reaches saturation (because all the receptors are occupied), and “stereoselectivity”.

Question 18

What is stereoselectivity?

Answer 18

The structure of a drug means that it can exist in two conformations, So this suggests that although a drug may contain the same chemical composition and sequence of chemical bonds, it is like how two different shoes are needed to fit our feet.

Question 19

What does a low KD tell us?

Answer 19

That the drug is very potent.

Question 20

What does KD stand for?

Answer 20

equilibrium dissociation constant

Question 21

The KD tells us what concentration is need to bind to how many receptors?

Answer 21

50%

Question 22

A low affinity is a ___ KD

Answer 22

high KD. Because affinity is 1/KD. So a low affinity means the drug is not very potent.

Question 23

What is k1 and k-1?

Answer 23

k1 is the association constant and k-1 is the dissociation constant.

Question 24

When you see square brackets around D, what does that tell you?

Answer 24

The concentration of the drug.

Question 25

What does DR mean?

Answer 25

Drug Receptor complex.

Question 26

What does the intrinsic efficacy alpha tell us?

Answer 26

the efficacy with which a drug effects a cell. The highest efficacy is 1.0.

Question 27

What is the intrinsic efficacy when a neurotransmitter binds to a receptor?

Answer 27

1.0

Question 28

What is an Agonist?

Answer 28

drugs that mimic the action of endogenous neurotransmitters. Have an intrinsic efficacy of 1.0.

Question 29

What is an Antagonist?

Answer 29

drugs that block the action of endogenous neurotransmitters. They themselves do nothing. Have an intrinsic efficacy of 0.0.

Question 30

What does a competitive and non-competitive antagonist do?

Answer 30

Competitive Antagonists block the receptor at the same site as the endogenous ligand. Non-competitive antagonists block the receptor at a site different from where the endogenous ligand binds.

Question 31

What does a partial agonist do?

Answer 31

When NT efficacy is high, acts as an antagonist, when NT efficacy is lower, acts as an agonist. Has an intrinsic alpha of between 0.0 and 1.0.

Question 32

What effect does an inverse agonist have?

Answer 32

Constitutive activity is reversed in the presence of these. It differs to the antagonist. Instead of blocking the receptor (the presence of an alpha of 0.0), it produces an opposite effect to the endogenous ligand (has an alpha of less than 0.0) This is therefore blocking constitutive activity.

Question 33

What is a PAM?

Answer 33

Post Allosteric Modulator. Has an intrinsic efficacy of 0.0. When seeing a DRC (Dose Response Curve) with a shift to the left, you’ll either see the work of an agonist or a PAM.

Question 34

What is the difference between indirect and direct?

Answer 34

Direct binds to the receptor sites and acts like a neurotransmitter.