Pharmacodynamics: Lecture 6 Flashcards
Histaminergic receptors are…
G-protein coupled receptors
What are the 2nd generation drugs of H1 receptors?
Cetirizine
Fexofenadine
What is unique about Fexofenadine?
It is a zwitter ion therefore highly H2O solube, resulting in the inability to cross the blood brain barrier and having no effect on the CNS
What are the 1st generation drugs of H1 and H2 receptors?
H1: Chloropheniramine
H2: Cimetidine and Ranitidine
Why are they 1st and 2nd generation drugs?
Because 1st generation they have less specificity of the receptor therefore they can cause side effects
2nd generation drugs are more specific
What is the function of H3 receptors?
They are used for cognition, thermoregulation, sleep/wake cycles and memory and hearing.
Give an example of an inverse agonist to H3 receptors?
Pitolisant
What is the function of H4 antagonists?
They function to treat chronic inflammatory diseases
The degree of potency is depended on…
Site of action
On the Beta adrenergic receptors which drug is more potent and which one is less potent?
Isoprenaline more potent
Noradrenaline less potent
On the Alpha adrenergic receptors which drug is more potent and which one is less potent?
Noradrenaline is more potent
Isoprenaline is less potent
Isoprenaline is a …
Exogenous drug meaning that it is not naturally produced by the body
Propanolol is a …..
Full antagonist
Which drugs can act on both the alpha and beta adrenergic receptors?
Carvedilol and Labetalol
What is a hazard of the these drugs?
They are not specific, therefore they can bind one to beta adrenergic receptors on smooth muscles of the bronchi and cause bronchoconstriction which can result into cardiac failure
