Podcast
Questions and Answers
What is the reason that catecholamines are ineffective if given orally?
What is the reason that catecholamines are ineffective if given orally?
- They undergo rapid degradation by MAO and COMT
- They are inactivated before they can reach systemic circulation (correct)
- They lack a catechol group
- They have a lower affinity for adrenergic receptors
What causes the pink or brown pigmentation in catecholamine-containing solutions over time?
What causes the pink or brown pigmentation in catecholamine-containing solutions over time?
- Bacterial contamination
- Reaction with light
- Decomposition of the solution
- Oxidation of the catecholamine molecule (correct)
How do noncatecholamines differ from catecholamines?
How do noncatecholamines differ from catecholamines?
- They undergo rapid degradation by MAO and COMT
- They have a higher affinity for adrenergic receptors
- They are substrates for COMT and metabolize slowly by MAO
- They lack a catechol group and metabolize slowly by MAO (correct)
What is a significant characteristic of noncatecholamines in terms of their ability to cross the blood-brain barrier?
What is a significant characteristic of noncatecholamines in terms of their ability to cross the blood-brain barrier?
Which drug is highly selective, acting at B2 receptors only?
Which drug is highly selective, acting at B2 receptors only?
At what doses does the selectivity of a drug to activate certain receptors decline?
At what doses does the selectivity of a drug to activate certain receptors decline?
What responses can be elicited by the activation of alpha-1 receptors?
What responses can be elicited by the activation of alpha-1 receptors?
Which enzymes are responsible for the quick metabolism of catecholamines?
Which enzymes are responsible for the quick metabolism of catecholamines?
What distinguishes indirect agonists from direct agonists in terms of their mechanism of action?
What distinguishes indirect agonists from direct agonists in terms of their mechanism of action?
What chemical groups characterize catecholamines?
What chemical groups characterize catecholamines?
Why can catecholamines not be used orally?
Why can catecholamines not be used orally?
What is the defining characteristic of noncatecholamines in relation to the blood-brain barrier?
What is the defining characteristic of noncatecholamines in relation to the blood-brain barrier?
What is the role of adrenergic agonists in activating adrenergic receptors?
What is the role of adrenergic agonists in activating adrenergic receptors?
What distinguishes catacholamines from noncatacholamines?
What distinguishes catacholamines from noncatacholamines?
Which group of drugs includes dopamine, epinephrine, isoproterenol, and ephedrine?
Which group of drugs includes dopamine, epinephrine, isoproterenol, and ephedrine?
What happens to catecholamines due to their chemistry?
What happens to catecholamines due to their chemistry?
What is the role of noncatecholamines in relation to the blood-brain barrier?
What is the role of noncatecholamines in relation to the blood-brain barrier?
What differentiates catecholamines from noncatecholamines in terms of oral use?
What differentiates catecholamines from noncatecholamines in terms of oral use?
What is the defining characteristic of adrenergic agonists known as sympathomimetics?
What is the defining characteristic of adrenergic agonists known as sympathomimetics?
What distinguishes catacholamines from noncatacholamines?
What distinguishes catacholamines from noncatacholamines?
What is the common structural feature of all catecholamines?
What is the common structural feature of all catecholamines?
Which enzyme is responsible for the rapid metabolism of catacholamines?
Which enzyme is responsible for the rapid metabolism of catacholamines?
Why can't catacholamines be used orally?
Why can't catacholamines be used orally?
Which class of adrenergic agonists includes dopamine and epinephrine?
Which class of adrenergic agonists includes dopamine and epinephrine?
What distinguishes indirect agonists from direct agonists?
What distinguishes indirect agonists from direct agonists?
What is the common mechanism of action for indirect agonists?
What is the common mechanism of action for indirect agonists?
Why do catacholamines have a brief duration of action?
Why do catacholamines have a brief duration of action?
What prevents catacholamines from crossing the blood-brain barrier?
What prevents catacholamines from crossing the blood-brain barrier?
What makes noncatacholamines different from catecholamines?
What makes noncatacholamines different from catecholamines?
What is the primary mechanism through which noncatacholamines exert their effects?
What is the primary mechanism through which noncatacholamines exert their effects?
Why are noncatecholamines able to act in the central nervous system unlike catecholamines?
Why are noncatecholamines able to act in the central nervous system unlike catecholamines?
