CPTP 3.15 Drugs used in Inflammation Allergy and Pain 3 Flashcards Preview

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Flashcards in CPTP 3.15 Drugs used in Inflammation Allergy and Pain 3 Deck (39)
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31

What is the effect of the affinity of glucocorticoids on the following:
1) 11𝛽 HSD2
2) Glucocorticoid receptor
3) Plasma binding proteins

1) Higher affinity decreases half life

2) Higher affinity increases duration of action (hence increases potency as the genes are expressed for longer)

3) Higher affinity increases half life, as there is less free drug (available for metabolism or filtration) so it is less rapidly eliminated

32

What is duration of action of a dose of drug dependent on?

1) Affinity for elimination
2) Affinity for target
3) Proportion of drug which is bound to plasma proteins
4) Lipophilicity of drug

33

What proportion of cortisol is bound to plasma proteins, and which protein is the most important of these?

How do the affinities of glucocorticoid analogues to this protein compare to cortisol?

90%

Corticosteroid-binding globulin

Cortisol analogues have lower affinities

34

What is the effect of drug lipophilicity on its half life?

Increases half life, as lipophilic drugs are more bound in adipose stores and so are less available for metabolism (can be cause of toxicity in the elderly)

35

What are the side effects of corticosteroid medications?

• Osteoporosis
• Infections
• Cataracts
• Depression OR euphoria
• Diabetes (from hyperglycaemia)

36

What is the main endogenous mineralocorticoid? What are its effects?

Aldosterone
• Acts on kidney tubules and collecting ducts to increase reabsorption of:
> Na+
> Bicarbonate
> Water
• DECREASES potassium K+ reabsorption

37

Adenomas of adrenal gland which causes excessive aldosterone secretion is called what? What are the symptoms?

Conn's syndrome
• Sodium and water retention, ECF fluid volume increases
• Hypokalemia
• Alkalosis
• Hypertension

38

Which disease can cause decreased secretion of mineralocorticoids and what are the symptoms?

Addison's Disease
• Desalination
• Hyperkalemia
• Decreased ECF

39

Why can you not administer aldosterone as a therapeutic agent?

What is given instead? How is this administered?

It undergoes 75% first pass metabolism

Fludrocortisone (a synthetic aldosterone) Orally given