Pharmacology- Drugs and Therapeutics

Question 1

What is a drug?

Answer 1

A chemical with a selective therapeutic action

Question 2

What is pharmacology?

Answer 2

Science that deals with the study of drugs and their actions on living systems

Question 3

What are the TWO integral branches of pharmacology?

Answer 3

Pharmocodynamics- What the drug does to the body- Drug action and mechanisms

Pharmocokinetics- What the body does to the drug- ADME

Question 4

What does the Adrenergic receptor- beta (B-1) do?

Answer 4

1. Increases heart rate
2. Increases cardiac muscle’s force of contraction

This is the adrenaline effect on the heart

Question 5

What does the adrenergic receptor- beta (B-2) do?

Answer 5

1. Relaxes the airway
2. Dilates smooth muscles

This is the adrenaline effect on the lungs

Question 6

What is biological specficity in therapeutic action

Answer 6

Right target

Question 7

What is chemical specifcity in therapeutic action

Answer 7

Right target binding site

Question 8

What is biolgical specficity in adverse/side effects?

Answer 8

Non-specific binding site

Question 9

What is chemical specificity in adverse/side effects?

Answer 9

Non-specific binding site

Question 10

What is specificity?

Answer 10

Target binding sites (receptors and its subtypes) provides the selectivity for the specific binding of drugs/ligands (Lock and Key system)

Question 11

What are the key drug binding sites?

Answer 11

1. Drugs as enzyme inhibitors- blocks the enzyme activity
2. Drugs as enzyme substrates

Question 12

Give examples of drugs and their enzymes and how they block the process.

Drugs as enzyme inhibitors

Answer 12

1. Sildenafil- targets the phosphodisterase enzyme and it blocks the
   enzyme, which function is intracellular breakdown
2. Neostigmine- enzyme is Acetylcholine esterase and it will inhibit neurotransmitter degradation
3. Ibuprofen (reversible), Aspirin (irreversible)- enzyme is cyclo-oxygenase and its function is messenger synthesis.

So the medication blocks that enzyme and then that will block the enzyme function/activity

Question 13

Which out of aspirin and ibuprofen binds to an enzyme and is reversible and which is irreversible?

Answer 13

Aspirin- irreversible
Ibuprofen- reversible

Question 14

What is reversible antagonists?

Answer 14

Readily dissociate from their receptor

Question 15

What is irreversible antagonists?

Answer 15

Form a stable, permanent or nearly permanent chemical bond with their receptor.

Question 16

What is pseudo-irreversible antagonists?

Answer 16

Slowly dissociate from their receptor

Question 17

Give an example of drugs as enzyme substrates

Answer 17

Dopamine- enzyme acting as a substrate.
E.g. dopamine precurosor L-DOPA for parkinson’s disease

Question 18

What is competitive binding?

Answer 18

Drug competes for the ligand active site. Can be reversible and irreversible

Question 19

Example of competitive inhibitor

Answer 19

Neostigmine (medication) is a comeptitive inhibitor with Acetylcholine which comeptes to bind with the Acetylcholine esterase

Question 20

During competitive binding neostigmine will compete with _____ to bind to the ligand active site of Acetylcholine (Ach) esterase?

Answer 20

Acetylcholine

Question 21

What is non competitive binding?

Answer 21

Drug binds at different site. Irreversible

Question 22

Example of non competitive binding

Answer 22

Cycloxygenase enzyme (COX) is responsible for the synthesis and release of prostaglandins (a pro-inflammatory cytokine). The synthesis of prostaglandin required arachidonic acid.

The arachidonic acid binds to the COX enzyme and releases the prostaglandins.

Example
Aspirin binds to the COX and it will not allow the arachidonic acid binding to the COX.

Question 23

The 3 class of drug targets

Answer 23

1. Enzymes
2. Drugs targeting transporters
3. Drugs targeting voltage-gated ion channels
4. Drugs targeting receptors

Question 24

Cocaine mechanism

Answer 24

Blocking of the transporter reducing the uptake of noradrenaline constant stimulation

Question 25

Drugs targeting transporters

Answer 25

The transporter is a protein, most of the drugs acting on the transporters are inhibitors. They block the transport

Question 26

Example of drugs targeting voltage gated ion channels

Answer 26

Its a trans membrane channel, its not a receptor because it doesn’t require binding of drug. It just recognizes the membrane potential. They have specific sensors to detect the inside, outside electric environment.
Once the channels open, it allows the ions to mobilise so its exclusively for ion movement. Inward/outward of ions. Could be Na, K, Ca, F ions (depending on which ion channel). The fastest

Question 27

Example of drug targeting ion channel

Answer 27

Lidocaine which is a local anesthetic. Blocks the Sodium (Na) channel.

Question 28

What are drugs targeting receptors?

Answer 28

proteins which respond to a endogenous messenger by initiating a signal
could be hormones, peptides, cytokines, neutrotrasnmitters etc

Question 29

What are the key types of receptors?

Answer 29

1. Nuclear receptors
2. Ligand gated ion channels
3. Catalytic receptors
4. G-protein coupled receptors

Question 30

Benefits vs risk (market authorisation of clinical drugs

Answer 30

Thalomid- treatment used to treat nausea in pregnant woman, caused birth defects

Question 31

Aspirin

Answer 31

Therapeutic action- COX inhibitor, anti-inflammatory (fever, pain, blood thinner)
Adverse effects- gastric upset, bleeding and ulcer. If given to children under 12, causes reyes syndrome which is liver and brain damage