Flashcards in CPTP 3.15 Drugs used in Inflammation Allergy and Pain 3 Deck (39)
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
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
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?
Cortisol analogues have lower affinities
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)
What are the side effects of corticosteroid medications?
• Depression OR euphoria
• Diabetes (from hyperglycaemia)
What is the main endogenous mineralocorticoid? What are its effects?
• Acts on kidney tubules and collecting ducts to increase reabsorption of:
• DECREASES potassium K+ reabsorption
Adenomas of adrenal gland which causes excessive aldosterone secretion is called what? What are the symptoms?
• Sodium and water retention, ECF fluid volume increases
Which disease can cause decreased secretion of mineralocorticoids and what are the symptoms?
• Decreased ECF