Lecture 5 Flashcards
WHat effect will an antagonist have on a receptor activation
No effect
a-adrenergic receptor antagonists (non-selective) drug names
Phenoxybenzamine and phentolamine
A1 selective drugs
prazosin, terazosin, doxazosin (ENDS WITH SIN)
A1 selective drugs ROA
Oral
A1 selective clinical use
HTN, BPH,
A non-selective clinical uses
Pheocromocytoma, hypertensive crisis
Side effects of A1 antagonists
Hypotension, inhibition of ejaculation, tachycardia
how does phenoxybenzamine form a covalent bond
Covalent bond forms at CL. It becomes irreversible
Why is phenoxybenzamine irreversible?
Haloalkene forms covalent bond
reversible non-selective a-adrenergic receptors antagonist name
phentolamine
Why are non-selective a-adrenergic blockers not used
A-2 blocking promotes release of NE
Why does phenoxybenzamine lead to long drug effects
It is a non-competitive irreversible drug. New receptors must be synthesized to restore receptor function.
Why non-selective a- adrenergic receptors not used for HTN?
A2 blockage will lead to increase of NE at heart and increased heart rate
a1 selective general structural feature.
Quinazoline ring
selective a1 antagonist clinical use
Hypertension, Reynauds disease, BPH
A1a antagonist name and use
Tamsulosin. Used for BPH. (A1a found in prostate urethra)
Why is tamsulosin less likely to lead to fall in BP?
Tamsulosin is very selective to A1a
B adrenergic antagonist structural feature
O/\OH/\NHR(3 carbons between NHR and O, with an aromatic on O)
All B blockers end with
Olol
Which side of the B blocker determines lipophilicity
Aromatic ring
Lipophilic B blockers tend to be on which organs
Liver
Lipophilic drugs tend to have
A. Strong 1st pass metabolism
B. weak 1st pass metabolism
A
Non-selective B blocker name
Propanolol
B antagonist pharmacologic effect
Decreased cardiac output
Decreased renin release
Increased bronchial airway resistance
Increased VLDL and decreased HDL
How does timolol treat glaucoma
Decreased intra occular pressure by reducing secretion of aqueous humor
B blocker effect on pupil size
No effect
Why are partial agonists preferred over agonists for HTN treatment
Less likely to cause bradycardia and lipid abnormalities
Name of 2 partial agonist drugs
pindolol
carteolol
How many rings do B1 selective drugs have? Does it have Meta or Para?
1 ring attached to O, it has para.
B1 selective blockers traits
Less bronchoconstriction and more bronchoconstriction
Why does atenolol have a longer half life than metoprolol
Nitrogen at the end makes it lipophobic, liver metabolism reduced
Does the liver metabolize more lipophilic or lipophobic drugs?
Lipophilic.
Lipophilic B1 drugs are ______lasting than lipophobic drugs
Longer
B1 blocker structure
Single ring, Para R group
Know B agonist structure
Know B blocker structure
Known A blocker structure
Effect of chronic B-receptor blockade
Upregulation (overexpression) of B blockers, leading to high sensitivity
Two mixed adrenergic enantiomer receptor antagonist names
Labetolol and carvedilol
Which receptor does labetalol block
A1, B1, B2
Which enantiomer of labetolol has B blocking activity
1R, 1R
Which enantiomer of labetolol has A blocking activity
1S, 1R
Physiological advantage of mixed adrenergic antagonist enantiomer
B blocking activity prevents tachycardia associated with A1 antagonist
Carvedilol acts on which receptors
A1, B1 and B2
Which enantiomers antagonize alpha receptors in carvedilol
Both enantiomers antagonize alpha receptors
Which enantiomer possesses b blocking activity
S enantiomer
How does metyrosine indirectly inhibit sympatholytic drugs
Inhibits tyrosine hydroxylase (RLS)
How does resperine indirectly inhibit sympatholytic drugs
Inhibits VMAT
How does bretylium indirectly inhibit sympatholytic drugs
Inhibits release of Norepinephrine
how does metyrosine inhibiting tyrosine hydroxylase affect the body
Depletes catecholamines everywhere
Clinical use of metyrosine
Management of pheochromocytoma
Bretylium tosylate inhibition mechanism
Inhibits release of NE and stops long term NE release
resperine inhibition mechanism
Inhibition of VMAT
