Konorev Flashcards
What are the alpha-1 adrenergic antagonists - types (generations) used to treat BPH?
What adverse reaction to both types cause?
second generation and third generation blockers
Both cause nasal congestion and flu-like symptoms.
What are the alpha-1 adrenergic antagonists - SECOND GENERATION blockers (3) used to treat BPH?
What are the adverse effects of these?
DAT (zosin) Doxazosin Alfuzosin Terazosin Causes syncope, dizziness, hypotension.
What are the alpha-1 adrenergic antagonists - THIRD GENERATION blockers (2) used to treat BPH?
What are the adverse effects of these?
TS (osin)
Tamsulosin
Silodosin
Causes ejaculatory dysfunction.
What are the 5-alpha reductase inhibitors used to treat BPH?
DUTe, that’s FINA (asteride)
Dutasteride
Finasteride
What is the normal MOA of alpha-1 AR (in BPH)?
What is the result?
Activation of a-1 AR results in IP3 and DAG accumulation, resulting in CONTRACTION of SMOOTH MUSCLE.
What is the result of alpha-1 adrenergic antagonists (in BPH)?
Inhibition of contraction of smooth muscle in vasculature, prostate, and other organs.
What is the first choice tx for BPH?
Does it reduce prostate size?
A-1 adrenergic antagonists
Does NOT REDUCE prostate size.
Are 5a-reductase inhibitors or alpha-1 antagonists more:
Faster acting and more effective.
Associated with less sexual dysfunction.
Faster acting - alpha-1 antagonist
Less sexual dysfunction - alpha-1 antagonist
What three receptors do second generation a-1 antagonists block?
Potently does what?
alpha-1A AR
alpha-1B AR
alpha-1D AR
Potently relax sm muscle in vasculature and prostate.
What second generation a-1 antagonists cause S/E of orthostatic hypotension, first-dose syncope, dizziness?
Terazosin and Doxazosin
What second generation a-1 antagonist is more UROSELECTIVE? Why is it uroselective?
What does it not require?
Alfuzosin is uroselective because of its pharmacokinetics, not AR subtype selectivity
It does not require dose titration.
What is dose titration?
Performed over several weeks after initiation of therapy.
Is Tamulosin more selective for alpha-1A AR or alpha-1B AR?
Where are they preferentially located?
greater selectivity for alpha-1A AR
alpha-1A AR located in PROSTATIC SMOTH MUSCLE
alpha-1B AR located in VASCULATURE
Tamulosin used to BPH patients with what condition?
Orthostatic HYPOTENSION
What third generation a-1 antagonist is a HIGHLY SELECTIVE inhibitor of alpha-1A AR?
What does this drug NOT CAUSE?
Silodosin
DOES NOT CAUSE ORTHOSTATIC HYPOTENSION
What are the drug interactions of alpha-1 antagonists with:
PDE5 inhibitors?
Cimetidine, Diltiazem?
Carbamazepine, PHT?
PDE5 inhibitors - marked systemic hypotension
Cimetidine (ulcers), Diltiazem (HTN) - DECREASED METABOLISM of alpha-1 antagonists
Carbamazepine, PHT - INCREASED alpha-1 metabolism
Which 5a-reductase inhibitor is nonselective?
Which is selective?
And for what types?
Finasteride is SELECTIVE, Type 2 (only) reductase inhibitor
Dutasteride is NON-SELECTIVE, (Type 1 and 2) reductase inhibitor.
MOA of 5a-reductase
TESTOSTERONE and other adrenocortical androgens CONVERTED TO DHT by 5a-reductase
Is DHT or testosterone a more potent androgen?
DHT is more potent than testosterone
MOA of 5a-reductase inhibitor.
- Inhibit formation of DHT in the prostate tissue by PREVENTING ANDROGEN RECEPTOR ACTIVATION
- SHRINK PROSTATE by 20%
Is type 1 or 2 5a-reductase responsible for epithelial tissue enlargement in the prostate?
Type 2!
Where are Type 1 and 2 5a-reductase localized to?
Localization:
Type 1 - skin, hair follicles, liver
Type 2 - prostate, genital tissue, scalp. RESPONSIBLE FOR EPITHELIAL TISSUE ENLARGEMENT IN PROSTSATE
Is 5a-reductase inhibitor or a-1 antagonist considered second-line BPH treatment, and what about its effect makes it this?
5a-reductase, because its effect is due to actual reduction in size of prostate and blockage of further enlargement.
5a-reductase epithelial volumes (cc) and timeline
Baseline
Intermediate
Endpoint
Baseline - 6cc
Intermediate, 6-18mo - 3.3cc
Endpoint, 24-30mo - 2cc
What class should be used for a patient with:
- Enlarged prostate of 40g or MORE.
- Patients with contraindications to adrenergic antagonists.
5a-reductase inhibitors be used
What combo therapy should be used when person has large prostate and a PSA of more than 1.4ng/ml?
Reductase inhibitors and a-1 antagonist