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Flashcards in Pharmacology Deck (43):
1

Where are alpha 1 receptors found and what is their action?

Found on vascular smooth muscle --> vasoconstriction
Found on urinary sphincter, iris, liver and kidney

2

Where are alpha 2 receptors found and what is their action?

Pancreatic islets --> decreased insulin secretion

3

Where are beta 1 receptors found and what is their action?

Located on heart --> increased HR and AV node conduction
JGA cells --> increase renin --> increase BP

4

Where are beta 2 receptors found and what is their action?

Lungs - bronchodilation
Vascular smooth muscles and arteries - vasodilation
Gi tract - decreased Gi motility
Pancreas - increase insulin secretion
Uterus - inhibition of labour

5

Where are beta 3 receptors found and what is their action?

Adipose tissue to increase lipolysis
Urinary sphincter- cause prevention of urination

6

What is the rawling thompson classification?

Classification of an adverse drug reaction

7

What is a type A drug reaction?

Augmented
Predictable, dose dependent and common, usually an extension of a primary effect e.g. hypotension and antihypertensive

8

What is a type B drug reaction?

Bizarre
Not predictable and not dose dependent. Often involves allergic reaction e.g. penicillin allergy

9

What is a type C drug reaction?

Chronic
Regular use of a medication overtime e.g. steroids and osteoporosis

10

What is a type D drug reaction?

Delayed
Example malignancies after immunosuppression

11

What is a type E drug reaction?

End of treatment
Occur after abrupt drug withdrawal

12

How do you report an adverse drug reaction?

Inform to MHRA - GMC stimulation
Report using yellow card scheme - early warning system for previously unrecognised reactions

13

What informations should you include on a yellow card?

What the drug is, what the reaction is, patient details and reporter details

14

What is a black triangle medicine?

Conditional approval of medication which is undergoing additional monitoring

15

What are the patient risk factors of an ADR?

Gender, age, neonates, genetic predisposition, allergies, polypharmacy, hepatic or renal failure, adherence problems

16

What are the drug risk factors for an ADR?

1. Low therapeutic index
2. Steep dose/response curve
3. Commonly causes ADR's

17

Name 5 causes of ADR's?

1. Pharmaceutical variation
2. Receptor abnormality
3. Abnormal biological system unmasked by drug
4. Abnormalities in drug metabolism
5. Drug-drug interaction

18

In a patient with anaphylactic shock, what are the first 3 management steps?

1. Commence basic life support ABC
2. Adreneline IM 500mg
3. High flow oxygen and IV fluids

19

How does adrenaline treat anaphylaxis?

Alpha 1 - vasoconstriction --> increase Bp and coronary perfusion
Beta 1 - positive ionotropic and chronotropic effects
Beta 2 - decrease oedema and bronchodilates
Increases cAMP which reduces release of inflammatory mediators

20

Name 4 of the clinical criteria for an allergy to a drug?

1. Doesn't correlate with pharmaceutical properties of drug
2. No linear relation with dose
3. Reaction similar to those produced by other allergens
4. Induction period of primary exposure
5. Disapearance on cessation
6. Re-apears on exposure
7. Occurs in a minority of patients on the drug

21

What is type 1 hypersensitivity?

Allergy
IgE mediated
Allergen identified --> IgE binds --> Mast cells activated --> granules released of histamine and cytokines
Cytokines induce a Th2 response

22

What is type 2 hypersensitivity?

Cytotoxic
IgG mediated.
Drug combines with protein, body treats it as foreign and forms antibodies IgG and IgM --> complement activation --> damaged to cells

23

What is type 3 hypersensitivity?

Immune Complex
Antigen and antibody form large complexes which activate the complement

24

What is type 4 hypersensitivity?

Delayed
T-cell mediated
Eg contact dermatitis

25

Name 5 barriers to concordance?

1. capacity and resources - e.g. cost of drugs
2. Concerns about mediation - worries about side effects
3. Necessity beliefs about medication - feel there is no need for the treatment
4. Practical barriers to adherence
5. specific beliefs about medication

26

How do you treat opioid induced respiratory depression?

ABC and IV Naloxone

27

How do opioids work?

Inhibit release of pain transmitters at spinal cord and midbrain, modulate pain perception in the higher centres (euphoria) changes the emotional perception of pain

28

What happens in phase 1 of drug metabolism?

Transformation of drug to polar metabolite catalysed by cytochrome P450

29

What happens in phase 2 of drug metabolism?

Conjugation step - involves formation of covalent bond between drug.phase 1 metabolite and endogenous substrate so they are less active and more water soluble

30

Name 4 things that drug absorption can be affected by?

1. Drug structure eg lipid soluble? pH?
2. Drug formulation e.g. capsule or coating
3. Gastric emptying- metabolism slowed down by food
4. First pass metabolism

31

Give an example of a drug which is a weak acid?

Aspirin

32

Give an example of a drug which is a weak base?

Propanolol

33

How do statins reduce lipids?

Block the rate limiting step in the cholesterol pathway - HMG- CoA reductase

34

What is first order kinetics?

Change in concentration at any time is proportional to concentration

35

What is zero order kinetics?

Change is concentration per time is a fixed amount of drug per time, independent of concentration

36

What is the definition of clearance?

Volume of blood plasma cleared of drug per unit of time

37

What is the definition of distribution?

Rate and extent of movement of drugs into and out of tissues from the blood

38

What is the definition of bioavailaibilty?

The fraction of the drug which reaches your circulation un-altered

39

What is the definition of half-life?

The time taken for the concentration to reduce by one half

40

What is the definition of efficacy?

How well a ligand activates a receptor

41

What is the definition of affinity?

How well a ligand binds to a receptor. Define the amount of drug required to produce 50% of the maximum, normally expressed as reciprocal unit

42

What is the definition of intrinsic ability?

Refers to the ability of a drug-receptor complex to produce a maximum functional response

43

What is the definition of pharmacokinetics?

The action of drugs in the body, including absorption, metabolism, distribution and elimination