Impotence Agents/ BPH agents

Question 1

what is the name of the first impotence agent back in the day that could only be injected into the penis

what is the route of injection into penis called

what other form was there eventually

Answer 1

alprostadil - a synthetic prostaglandin used in impotence

injecting into penis= caverject

muse= urethral suppository route developed little bit later

Question 2

scientific studies of the erection process showed that erection requires _____________ of the nonvascular smooth muscle of the corpus cavernosa

Answer 2

relaxation

Question 3

how do PDE-5 inhibitors act

Answer 3

act to increase c-GMP by inhibiting breakdown by phosphodiesterase isoform 5 (PDE-5)

c-GMP = promotes smooth muslce relaxation and increased blood flow to penis

Question 4

what is the role of NO in erection

Answer 4

released into corpus cavernosum during sexual stimulation which act on guanylate cyclase which increases cGMP levels

cGMP (enzyme) promote smooth muscle relaxation and increased blood flow

Question 5

what is the role of PDE-5 in erection

Answer 5

breaks down c-GMP so turns off erection

we target this so it cannot turn off erection

Question 6

what are the impotence agents

Answer 6

sildenafil citrate (viagra)

vardenafil (levitra)

tadalafil (cialis)

Question 7

sildenfil

Answer 7

viagra

4000 fold selectivity for PDE-5 than PDE-3

and 10 fold selectivity for PDE-6

active metabolite that accounts for 20% of activity

Question 8

what is the difference between

PDE-3
PDE-5
PDE-6

Answer 8

PDE-3= cardiac

PDE-5= penis

PDE-6= eye

aka side effects in vision changes and what not

Question 9

absorption / distribution of impotence agents

Answer 9

rapidly absorbed

40% bioavailable

max serum conc are seen in 2 hours

Question 10

Metabolism/ excretion of impotence agents

Answer 10

significant drug interactions
- especially nitroglycerin (NTG) - cardiac disease drug

cleared via CYP3A4 (didnt go over)

Question 11

what is the difference of half lives for the impotence agents !!!!!!

Answer 11

sildenfil= 4 hour half life

tadalafil = 36 hours
- means drug is present, can develop erection within those times

• pts like the ability for spontaneity

Question 12

PG role in erection

Answer 12

within seminal fluid resolve erection upon ejaculation - refractory period

they also cause the erection

Question 13

what is the newer med for women’s libido!!

Answer 13

filbanserin (addyi)

serotonin agonist/antagonist and dopamine agonist

only approved for hypoactive sexual desire disorder!!!
-not because too stressed/tired/traumatized

Question 14

what is a brand new med for hypoactive sexual desire disorder (HSDD)

what receptor does it work on

Answer 14

bremelanotide (vyleesi)

• increases desire
• decreases distress
• injection
• expensive

works on the melanocortins receptor agonist (excitatory signal)