BPH and ED Pharm Flashcards
how long do SAR inhibitors take to provide relief of sx in BPH
3-6 months
*shrinks and prevents enlargement
what are the 3 categories of drugs used for BPH
a1 antagonist (-osin)
steriod 5a reductase inhibitor (-steride)
PDE-5 inhibitors (-afil)
name of PGE1 agonist used to tx ED and function
alprostadil (caverject) is a penile injection
-increases level of adenylate cyclase –>increased cAMP–> decreases calcium levels–> smooth muscle relaxation –> erection
which PDE-5 inhibitor has the quickest onset ? what is the onset? what is the onset for the other ones?
avanafil (15 min if high dose or 30 min if normal dose)
**all others are 60 min
finasteride vs dutasteride
MOA: SAR inhibitiors TX: BPH finasteride is specific for SAR 2 dutasteride affects both SAR 1 and 2 **finasteride causes a 70% decrease in serum DHT vs 90% in dutasteride ; both cause 90% DHT decrease in prostate
a prostate that has undergone hyperplasia has excess ____
SAR 2
steriod 5alpha reductase
doxazosin MOA, specificity, adverse effects, drug interactions
MOA: alpha 1 antagonist specificity: alpha 1 >>>>>> alpha 2 *not uroselective side effects: postural hypotension, fatigue, dizziness Drug interactions: PDE5 inhibitors
alfuzosin MOA, specificity, adverse effects, drug interactions
MOA: alpha 1 antagonist specificity: All A1 types *IS FUNCTIONALLY UROSELECTIVE adverse effects: QT prolongation drug interaction: PDE5 inhibitors , increased CYP34A substrates
how does PDE-5 inhibitors treat ED
Nitric oxide leads to increased cGMP which decreases calcium levels and induces smooth muscle relaxation in order to form an erection.
- cGMP is degraded by PDE-5 into 5’-GMP
- by inhibiting the level of cGMP degradation you can cause an erection to maintain longer
- the drug works by competing with cGMP to bind to PDE-5 and using it all up to prevent degradation
- must have an erection prior to use; does not induce an erection
examples of lower urinary tracts sx (LUTS)
interrupted stream weak stream feeling of urgency dribbling feeling of fullness increased frequency (in middle of night) hesitation
what are the 2 categories of drugs used for ED
PDE-5 inhibitors (-afil) PGE1 agonist (-adil)
risk factors for ED
obesity, smoking, stress
*SOS
name of the 4 PDE-5 inhibitors used to treat ED
- tadalafil
- sildenafil
- vardenafil
- avanafil
* fil a VAST
silodosin MOA, specificity, adverse effects, drug interactions
MOA: alpha 1 anatagnost
specificty: alpha 1 A and D > B
*uroselective
side effects: reduced ejaculation and IFIS (inter operative floppy iris syndrome)
drug interaction: PDE5 inhibitors , increased CYP34A substrates
adverse effects of finasteride and dutasteride
ejaculation disturbances ED depressed libido gynecomastia *no drug interactions
tamsulosin MOA, specificity, adverse effects, drug interactions
MOA: alpha 1 anatagnost
specificty: alpha 1 A and D > B
*uroselective
side effects: reduced ejaculation and IFIS (inter operative floppy iris syndrome)
drug interaction: PDE5 inhibitors , increased CYP34A substrates
what causes prostate enlargement
aging and DHT
contraindications of PDE-5 inhibitors
organic nitrates (vasodilators) - causes extreme and dangerous hypotension
terazosin MOA, specificity, adverse effects, drug interactions
MOA: alpha 1 antagonist specificity: alpha 1 >>>>>> alpha 2 *not uroselective side effects: postural hypotension, fatigue, dizziness Drug interactions: none
adverse effects of aloprastidil ? how to tx it?
prolonged erection (priapism) that can develop into a medical emergency (need to evacuate clogged blood)
-symoathomimetic (phenylephrine)
which PDE-5 inhibitor is approved to treat BPH and ED
tadalafil
alpha-1 A vs alpha-1 B vs alpha-1 D function
A- prostate smooth muscle contraction
B-vascular constriction
D- spinal cord control of urinary function
D>A detrusor muscle relaxation
*detrusor muscle relaxation allows filling and retention, contraction of muscle occurs during urination
which BPH drug provides best mono therapy for prompt relief of symptoms (in days)
alpha 1 antagonist group
which PDE-5 inhibitor has the longest duration of action and longest half life? what is the duration of it and the other drugs?
tadalafil (36 hours) (1/2 life = 18 hours)
**all others are 4 hours (1/2 life 4 hours)
when to use combo therapy for BPH with Alpha 1 antagonist and SAR inhibitors
- severe BPH sx
- known large prostate
- no response to mono therapy
