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Veterinary Pharmacology And Nursing Frameworks > Pharmacology > Flashcards

Flashcards in Pharmacology Deck (103):
1

What is pharmacology

Study of drug action on the body

2

What is pharmacokinetics

The study of what the body does to a drug

3

What is pharmacodynamics

Physiological effects of a drug on the body

4

What does ADME mean in pharmacokinetics

Absorption
Distribution
Metabolism
Excretion

5

If a drug is given orally, where does it go

GI tract

6

What happens when a drug is absorbed by the GI tract

Goes to the liver where some drugs are broken down

7

How can elimination happen

Broken down by liver
Excreted by kidneys
Excreted via lungs

8

Where does pharmacological action happen

Circulation tissue space

9

What is absorption

Rate and extent at which a drug leaves its site of administration and enters the circulatory system

10

What can impede the efficacy of a drug

Route of administration e.g. orally or rectally

11

What can enhance or impair the rate of absorption

Presence of food

12

What happens when the GI tract is compromised

A parenteral route must be considered

13

Why does location of drug administration need to be considered

Tissue perfusion will also impact on absorption

14

What is first pass effect

When a drug has been absorbed into circulation it is transported to the liver via hepatic portal system where it is metabolised

15

Why do we have to reduce the amount of active drug being distributed within the body

Because some drugs undergo extensive hepatic metabolism

16

What is produced by first pass effect

Drug and metabolites

17

How can first pass effect be avoided

Using parenteral route which bypasses this process and provides body with a more accurate dosage

18

Once a drug has been metabolised by the liver, where does it go

Enters the systemic circulation and travels in the plasma to its site of action

19

What happens once a drug has reached the desired site of action

It leave the plasma and enters interstitial fluid then the cells and combines cellular receptors to create an action

20

What affects drug distribution

Drug formulation
Blood flow to that area
Binding/unbinding of the drug to plasma proteins
Presence of anatomic barriers

21

What are fat loving drugs

Lipophilic

22

What are water loving drugs

Hydrophilic

23

Which route of administration is best for hydrophilic drugs

IV, IM as they enter the extra cellular fluid

24

Which route of administration is best for lipophilic drugs

Orally or SC as needs rap diffuse through a cell membrane

25

When are drugs most rapidly distributed. Give examples

When entering well perfused tootsies e.g. active skeletal muscle, liver, kidney, brain

26

Which tissues are poorly perfused

Inactive skeletal muscle and adipose fats

27

What remains in the circulation as a reservoir for circulating drugs

Plasma proteins

28

What happens when a drug binds with a plasma protein (albumin)

Termed inactive and unable to migrate into the tissues to exert its effect

29

What happens to drugs that do not bind to plasma proteins

Able to migrate into tissues and exert effect

30

What happens to the amount of unbound and bound drug after plasma protein binding

Drug within circulation will remain the same

31

What happens to bound molecules when unbound drug molecules move into tissues during plasma protein binding

Bound molecules are released to maintain the balance

32

Why is protein binding significant

Because plasma protein levels are reduced due to disease as the standard dose could cause toxic concentrations

33

Which organs can cause toxic concentrations of drugs

Liver, GI, kidney

34

Why are anatomical barriers important

In the capillaries of the CNS as endothelial cells in the brain are closely packed together preventing some drugs from entering

35

What type of drugs can cross the blood:brain barrier

Lipophilic

36

What happens to drugs before they can be excreted

Biotransformation / drug metabolism

37

Where does bio transformation happen

Generally in liver (lungs and kidneys)

38

What happens when drugs are metabolised

Enzymes modify the molecules of the drug to enable elimination

39

What does enzyme action do during metabolism

Provokes chemical reactions that cause drug to become hydrophilic enabling drug to be eliminated by kidneys

40

Factors affecting drug metabolism

Species, age, nutritional status, health status

41

Where does excretion take place

Liver, lungs, skin, glands e.g. mammary, sweat and salivary

42

Why does excretion route need to be taken into consideration

Could compromise effectiveness of excretion when specific organ is diseased

43

Why is pharmacokinetics important

Formulates suitable drug dose and dosing regime to facilitate therapeutic effect

44

Pharmacokinetic parameters:

Bioavailability
Volume of distribution
Clearance and half life

45

What is bioavailability

The quantity of the administered drug reaching systemic circulation

46

When is bioavailability reduced greatly from 100% IV

When given orally

47

What is volume of distribution

Measurement relating to the amount of drug absorbed within the plasma, body tissues and cells

48

What properties of a drug affect a drugs ability to distribute

Interaction with plasma proteins, drug for me.g, hydrophilic or lipophilic

49

What is clearance

Volume of blood cleared of a drug from eliminating organ e.g. liver, kidneys

50

What is important when devising a drug regime for a patient regarding clearance

To enable suitable serum drug concentrations. Must be equal to the rate of drug administration

51

What is half life

Time it takes for drug to be reduced by 50% at current concentration level

52

What can greatly affect the plasma concentration of a drug

Efficacy of kidneys and liver as half life will take longer to decrease

53

Why is pharmacodynamics important

Ensured indication for using specific drug has been discussed and any contraindications have been evaluated

54

What to cellular receptors normally interact with regarding drug-receptor interaction

Endogenous Ligands

55

What are endogenous ligands

Natural substances e.g hormones and neurotransmitters

56

How does a drug exert its effect

By binding to a protein receptor found in the cell membrane, cytoplasm or nucleus

57

What is affinity

Ability of a drug to bind to receptor

58

What is efficacy

Ability of a drug to produce the desired effect

59

What is an agonist

Drug that has good affinity and efficacy

60

What is an antagonist

Drug that has poor affinity and efficacy

61

What is the therapeutic effect

Effect of a drug within an Animals body to control a specific disease or manage physiological function. The narrow dosage parameter a drug has to remain in, to enable therapeutic effect to be efficient

62

What happens when therapeutic range is too high

May produce toxic effect. MSC: maximum safe concentration or MTC: minimum toxic concentration

63

What happens when the therapeutic range is too low

Prevents the desired effect and termed minimum effective concentration (MEC)

64

How long does a prescription last for

6 months for normals drugs. Can be on repeat
28 days for controlled drug. Cannot be on repeat

65

Requirements for POM-V

Once prescribed by VS who is confident the person using it is competent to do so.

Drug will have safety issues or concerns, deemed that specialist knowledge is required, drug has narrow safety margins and is government policy

66

Requirements for POM-VPS

Registered qualified person e.g. vs, pharmacist or SQP. Prior clinical assessment is not prerequisite

67

Requirements for POM-V (CD)

Dispensed once prescribed by VS
Drug access must be by person deemed confident by vs to handle
VS will have key

68

Pros for oral administration of medication for owners

Easy for most owners

69

Cons for oral administration of medication

Slow compared to parenteral
Not suitable for unconscious/vomiting patient
Food can impact on administration
Can cause irritation (V/D)
Gastric acid can denature drugs
Liver enzymes may break down drugs before it reaches systemic circulation

70

Pros of parenteral administration of medication

Directly into systemic circulation therefore 100% bioavailability
Drug action achieved quickly
Drugs can irritate skin

71

Cons of parenteral administration of medication

Requires asepsis
Must be solution
Must be given slowly
Irritant drugs can cause severe tissue damage
Catheter care

72

Pros of IM administration of medication

Can be suspended drug
Absorbed quicker than SC

73

Cons of IM medication administration

small volumes at a time
2ml in cats
5ml in Dogs

74

Pros of SC administration of medication

Can be large amounts of fluid
Generally pain free

75

Cons of SC medication administration

Multiple sites should be used for high volumes of fluid to avoid discomfort
Possible damage to small blood vessels
Local reaction to drug can occur

76

Where do you admin IM injections and how long does it take

Quadriceps of hindlimb takes 20-30 minutes

77

How long does SC injection take to work

30-45 minutes

78

What is intaosseous

Injection into bone marrow in medulla of long bone; when IV is compromised e.g. birds

79

What is epidural

Aseptic technique of injecting into vertebral canal outside the duramater

80

What is intrarthecal

Aseptic technique of injection into subarachnoid space containing cerebrospinal fluid; contrast media for myelography

81

Subconjunctiva

Into conjunctival membrane of eye

82

Legal requirements to f dispensing label for medication

-Name and address of animal and owner
-Name and address of approved premises supplying the medication
-Date of supply
-The words ‘keep out of reach of children’
-The words ‘for animal treatment only’

83

Discuss the cascade system

1. Veterinary medicinal produce authorised in the UK for another condition in the same species or another species with the same condition
2. Medicinal product authorised in uk for human use or veterinary product authorised in eu member state for use in animal species
3. Veterinary product made by vs, pharmacologist or person holding manufacturers authorisation as prescribed by vs

84

Key information given to clients when dispensing medication

-Technique demonstration e.g. using pill guns, filling syringes and tube feeding.
-Specific requirements for drug e.g. before food
-Potential side effects/contraindications and client told to phone if this happens
-Told when to stop medication and told to return an medication if necessary
-Person dispensing should be confident client is happy doing what is expected

85

Requisition requirements for schedule 2 drugs

Made in writing to supplier, signed by vs

86

Storage requirements for schedule 2 drugs

Locked cabinet secured to wall or floor
Destruction must take place in front of authorised person
Invoices kept for 2 years

87

Dispensing requirements for schedule 2 drugs

Drug register kept with all purchases and each supply within 24 hours

88

Requisition requirements for schedule 3 drugs

Made in writing to supplier, signed by vs (same as schedule 2)

89

Schedule 2 drugs

Morphine
Pethidine
Fentanyl
Ketamine

90

Storage requirements for schedule 3 drugs

Locked cabinet
Invoices kept for 2 years (same as schedule 2)

91

Dispensing requirements for schedule 3 drugs

No register

92

Examples of schedule 3 drugs

Pentobarbital
Phenobarbital
Buprenorphine
Tamazepam

93

Requisition requirements for schedule 4 drugs

Prescription bed by MRCVS

94

Storage requirements for schedule 4 drugs

None

95

Dispensing requirements for schedule 4 drugs

Prescribed by MRCVS but should be checked. Can be dispensed by SQP/vet/nurse as long as checked

96

Examples of schedule 4 drugs

Benzodiazepines
Anabolic steroid

97

Examples of schedule 5 drugs

Coedine
Morphine (in less than specified amounts)

98

What does p.o or per os mean

By mouth

99

What does a.c mean

Before food

100

What does p.c mean

After food

101

What does q. Mean

Every

102

What does p.r.n mean

As necessary

103

What does a.s mean

Sufficient quantity