Clinical Pharmacology and prescribing drugs

Question 1

What is pharmacodynamics?

Answer 1

What the drug does to the body

Question 2

What is pharmacokinetics?

Answer 2

what the body does to the drug

Question 3

What is clinical pharmacology?

Answer 3

the study of clinical effectsof drugs on patients​

Question 4

What factors affect the choice of therapeutics?

Answer 4

Underlying disease
Drug data (efficacy, safety, licensed etc.)
Owner needs (financial, physical)
Patient factors
Practice (stock)
Compliance (training and education)

Question 5

What are the different types of molecules that drugs can target?

Answer 5

Receptors (agonists or antagonists)
Ion channels
Structural Proteins
Enzymes
Carrier molecules
DNA

Question 6

Describe the dose response curve of agonists

Answer 6

Response increases as dose increases up to a plateau

Question 7

What is a full agonist?

Answer 7

A drug that reaches 100% response

Question 8

What is a partial agonist?

Answer 8

A drug that does not elicit a full response (often used in conjunction with other drugs)

Question 9

What is potency?

Answer 9

amount of drug required to produce 50% of its maximal effects (ED50).

Question 10

What is efficacy?

Answer 10

the maximum therapeutic response that a drug can produce

Question 11

What is drug specificity?

Answer 11

capacity of a drug to cause a particular action in a population - has one desired effect

Question 12

What is drug selectivity?

Answer 12

relates to a drugs ability to target only a selective population in preference to others

Question 13

What is the therapeutic index (TI) of a drug

Answer 13

The difference between a toxic and therapeutic doses
- High TI gives more scope to increase drug before toxic effects occur
- High TI is safer

Question 14

Describe competitive antagonists

Answer 14

Compete with agonists for receptor binding site
Chemical structure similar to agonist
Increasing agonists overcomes antagonists

Question 15

Describe non-competitive antagonists

Answer 15

bind to different receptor site or block ‘post’ binding chain of events

Question 16

What is the effect of antagonist on a dose response curve?

Answer 16

shifts it the right
- agonist potency decreases
- greater conc of agonist required to reach max efficacy

Question 17

What is the action of drugs on enzymes?

Answer 17

Bind to catalytic site
Inhibit normal reaction, thus decreased production of undesired product

Question 18

What is tachyphylaxis?

Answer 18

loss of target sensitivity

Question 19

Giving a drug continuously decreases the effect due to…

Answer 19

Change in receptors (become resistant to drug stimulation/conformational changes)
Loss of receptor number
Exhaustion of mediators
Increased metabolic degradation of the drug
Physiological adaptation (crosstalk between body systems, other body systems compensate for the drug’s action)
Drug transporters (active extrusion of the drug)

Question 20

What are the different drug distribution categories?

Answer 20

POM-V (Veterinary Surgeon) - prescription only
POM-VPS (Vet, Pharmacist, SQP) - prescription only
NFA-VPS (Vet, Pharmacist, SQP) - non-food producing animals
AVM-GSL (General Sales List)
Schedule 6 exemption products

Question 21

Describe the prescription of a POM-V drug

Answer 21

Can only be prescribed by a veterinary surgeon following a clinical assessment
Medicine supplied from registered premises

Question 22

What does VPS stand for in drug prescriptions?

Answer 22

It dictates who can prescribe certain drugs
V - vets
P - pharmacist
S - SQP (suitably qualified person)

Question 23

When is a medicine classed as POM-V?

Answer 23

required strict limitation for safe use
requires specialised knowledge to use/apply
narrow safety margin requiring above average care
government policy to demand professional control e.g., control of antibiotics

Question 24

What is the difference between POM-V and POM-VPS

Answer 24

Does not need a clinical assessment prior to prescription
Does not need to be administered by vet, only a competent person

Question 25

What must you do prior to prescribing a POM-VPS drug?

Answer 25

Be satisfied the person administering the drug is competent Advise on safe administration and warnings/contraindications

Question 26

What must be done before prescribing a NFA-VPS drug>

Answer 26

No clinical assessment required Person administering must be competent Advise on safe administration and warnings/contraindications

Question 27

What are medicines in the small animal exemption scheme?

Answer 27

Medicines for use in certain pet species (aquarium fish, cage birds, ferrets, homing pigeons, rabbits, small rodents and terrarium animals) Can only be prescribed by vets after a clinical exam

Question 28

How are safety standards regulated in the SAES?

Answer 28

These medicines are exempt from the requirement for a marketing authorization and not required to prove safety, quality or efficacy, but must be manufactured to same standards as authorized medicines and are subject to pharmacovigilance reporting

Question 29

Why may a drug be controlled?

Answer 29

it can be misused by humans for recreational purpose May be a drug with a large effect

Question 30

What factors must be considered in the supply process of a prescription?

Answer 30

Access by staff/public Stock control and out of date medicines Labeling Authorisations for prescribing Safety and contraindications Hand over SOPs Prescription has all necessary details on it

Question 31

What are the rules regarding records of drugs?

Answer 31

Receipt and supply of prescription medicines Date of supply/receipt, name, batch, quantity, address Copies of all written prescriptions Records of recent audit Imported drugs maintained MUST BE KEPT FOR 5 YEARS