clinical pharmacology

Question 1

Define pharmacodynamics

Answer 1

What the drug does to the body

Question 2

Define 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 interacting considerations do we need to be aware of when prescribing drugs

Answer 4

Question 5

Name the different types of molecules drugs can target (+ examples)

Answer 5

Receptors (e.g. benzodiazepines - GABA receptor agonists).

Ion channels (e.g. verapamil -calcium channel blockers).

Enzymes (e.g., ACE inhibitors).

Structural proteins (e.g. Taxol - Tubulin agonist)

Carrier molecules (e.g. digoxin)

DNA (e.g. Doxorubicin - anticancer agents).

Question 6

What is a dose response curve

Answer 6

Question 7

Draw a dose response curve for a partial vs full agonist

Answer 7

Fentanyl is full agonist because it reaches maximum response (analgesia)
So is morphine but its less potent (need more for same response)

Partial agonist: has an analgesic effect but wont elicit full response

Don’t use fentanyl right away because it might be really potent but can also have toxic effect

Question 8

Define potency

Answer 8

amount of drug required to produce 50% of its maximal effects (ED50). Used to compare drugs within a chemical class

Question 9

Define efficacy

Answer 9

the maximum therapeutic response that a drug can produce (example: morphine vs buprenorphine)

Question 10

Draw a graph for this

Answer 10

Question 11

define specificity

Answer 11

capacity of a drug to cause a particular action in a population

Example: a drug with absolute specificity of action might decrease or increase the specific function of a given target. It must do either, but not both.

Question 12

Define selectivity

Answer 12

relates to a drugs ability to target only a selective population i.e. cell/tissue/ signalling pathway, protein etc in preference to others.

Example: Atenolol is a B1-selective adrenoreceptor antagonist, while propranolol is a non-selective B-antagonist

Question 13

What is the therapeutic index (TI)?

Answer 13

The therapeutic index is the difference between toxic and therapeutic doses

A high TI indicates a safer drug, while a low TI requires careful dosing.

Question 14

What is drug antagonism and what are the types?

Answer 14

Antagonism occurs when a drug inhibits the effect of an agonist.

1. Competitive antagonism:
   - antagonist competes with agonist for same receptor binding site.
   - Can be overcome by increasing agonist concentration.
2. Non-competitive antagonism:
   - antagonist binds to different site or inhibits post-binding pathways.
   - Can’t be overcome by increasing agonist concentration.

Question 15

How does the presence of a competitive antagonist affect drug receptor curves?

Answer 15

dose-response curve shifts to the right.

Agonist potency decreases, requiring a higher concentration to achieve the same effect.

The maximum efficacy of the agonist remains achievable, provided a sufficient concentration is administered.

Key example: Methadone vs. Naloxone, where Naloxone acts as a competitive antagonist.

Question 16

What is the action of drugs on enzymes

Answer 16

Bind to catalytic site

Inhibit normal reaction, thus
Decreased production of undesired product

Question 17

What is tachyphylaxis and why does it occur

Answer 17

Loss of target sensitivity

effect of drug can decrease when given continuously or repeatedly due to:
- Change in receptors (become resistant to drug stimulation/conformational changes)
- Loss of receptor number
- Exhaustion of mediators
- Increased metabolic degradation of drug
- Physiological adaptation (crosstalk between body systems, one takes over)
- Drug transporters (active extrusion of the drug)

Question 18

What is the purpose of The Veterinary Medicines Regulations 2013

Answer 18

Question 19

How is veterinary medicine regulated?

Answer 19

Through data assessment, certification, prescribing/dispensing, inspections, and post-marketing surveillance for quality, safety, and efficacy.

Question 20

Name the categories of veterinary medicines

Answer 20

Prescription-only medicine – Veterinary (POM-V).

Prescription-only medicine – VPS (Vet, Pharmacist, SQP).

Non-food animal – VPS (NFA-VPS).

AVM-GSL (General Sales List).

Small Animal Exemption Scheme (SAES).

Question 21

What is a suitably qualified person?

Answer 21

SQP works according to a VMD Code of Practice

Training covers legislation, basic anatomy & physiology & basic disease challenges plus species modules: farm animal; equine; companion animal & avian leading to different qualification

To supply medicines SQP must have passed relevant species module & base exam

Question 22

What is the role of the Veterinary Medicines Directorate (VMD)?

Answer 22

To regulate veterinary medicines, ensuring safe use, manufacturing, and provision of reliable information.

Question 23

What is the difference between POM-V & POM-VPS?

Answer 23

POM-V:
- Requires a clinical assessment by a vet
- for high-risk medicines needing professional control.
- only prescribed by veterinary surgeon

POM-VPS:
- Can be prescribed by vets, pharmacists, or SQPs
- without clinical assessment
- for endemic disease prevention.

Question 24

When is a medicine classified as a POM-V?

Answer 24

It requires strict limitation on its use for specific safety reasons

It requires specialized knowledge of veterinary surgeon for its use/application

It has narrow safety margin requiring above average care in its use

It is government policy to demand professional control at a high level (for example, antimicrobials and Controlled Drugs).

Question 25

What are Non-Food Animal VPS (NFA-VPS) medicines, and how are they prescribed and supplied?

Answer 25

Purpose:
- For companion animals (excluding horses) to prevent or limit effects of endemic disease.

Prescribing and Supply:
- Supplied by vet, pharmacist, or SQP.
- No clinical assessment required.
- supplier must ensure person administering medicine is competent & intends to use it for authorized purpose.

Requirements:
- Minimum amount needed for treatment should be supplied.
- Risks to user, animal, or environment should be mitigated through advice & training.

Question 26

What are the other categories of drugs

Answer 26

Controlled drugs

Specified feed additive

Question 26

What is the Small Animal Exemption Scheme (SAES), and how does it work?

Answer 26

Purpose:
- Covers medicines for specific pet species such as aquarium fish, cage birds, ferrets, homing pigeons, rabbits, small rodents, & terrarium animals.

Exemptions:
- These medicines are exempt from requiring marketing authorization.
- They are not required to prove safety, quality, or efficacy.

Standards:
- Must still be manufactured to same quality standards as authorized medicines.
- Subject to pharmacovigilance reporting.

Supply and Sale:
- Treated similarly to AVM-GSL (General Sales List) medicines.

Question 27

Define prescribing

Answer 27

“any prescription for a veterinary medicinal product issued by a professional person qualified to do so in accordance with applicable national law.”

Question 28

What factors must a prescriber consider when deciding which product to supply?

Answer 28

• circumstances of animals being treated.
• available authorized veterinary medicinal products.
• need for responsible use of medicines.
• Prescribing minimum amount necessary for treatment.
• competence & abilities of person administering medicine.
• Any available animal health plan.

Question 29

What are the key requirements for records, storage, and disposal of medicines?

Answer 29

Records kept for 5 years.

Include details of supply, batch, and recipient.

Safe storage (correct temperature, no contamination).

Proper disposal to prevent misuse or environmental harm.