Drugs and Sex

Question 1

What are the two main ways drugs can affect sexuality?

Answer 1

1. alteration of libido
2. alteration of performance (erection/lubrication/orgasm)

Question 2

what hormones increase libido in males and females?

Answer 2

testosterone

dopamine

Question 3

which hormone increases libido in females only?

Answer 3

estrogen

Question 4

what hormones decrease libido in males and females?

Answer 4

prolactin

serotonin

norepinephrine (alpha 2)

Question 5

what hormone decreases libido in men?

Answer 5

estrogen (feeds back and lowers T levels)

Question 6

what are the parasympathetic nerves involved in penile or clitoral erection/lubrication?

Answer 6

S2-S4

Question 7

what are the sympathetic nerves involved in ejaculation in men and contraction of the uterus, fallopian tubes and vagina in women?

Answer 7

T12-L3

Question 8

what are the somatic nerves that contribute to erection and orgasm?

Answer 8

S2-S4

Question 9

the typical effect of drugs that interferes with erection are what two things?

Answer 9

• peripheral anti-muscarinic actions
• decreased blood flow

Question 10

the typical ways in which drugs act to decrease libido are:

Answer 10

increasing prolactin secretion

blocking androgenic action (anti-androgenic)

Block Dopamine, NE or ACh (muscarinic)

enhance 5-HT

sedation

Question 11

the most common ways drugs interfere with orgasm are:

Answer 11

alpha 1 blockade

local anesthetic

sedatives

Question 12

what are the treatments for premature ejaculation? What is the most significant side effect?

Answer 12

local anesthetics

drugs that delay orgasm:

clomipramine (TCA)

thioridazine (neuroleptic antipsychotic)

MAOIs

benzodiazepines

***but, these drugs also inhibit libido

Question 13

what are some drugs that enhance libido?

Answer 13

Testosterone (both males and females - lower doses in females)

Dopamine agonists:

L-DOPA

Bromocriptine -used in prolactinemia

Apomorphine - in clinical trials

methlyphenidate (Ritalin)

bupropion (Wellbutrin)

Question 14

what is a major drug-induced cause of impotence?

Answer 14

alcohol abuse

Question 15

what was commonly used before PDE5 inhibitors to treat ED?

Answer 15

Prostaglandin E1 (alprostadil)

injectable and uretrhal suppository

acts by vasodilating

SE: hypotension, mild penile pain, occasional priapism

Question 16

what are the differences among the PDE5 inhibitors?

Answer 16

pharmacokinetics and price

Question 17

what is the MOA of PDE5 inhibitors?

Answer 17

NO acts on a pathway in the endothelial and or neural cells to convert guanylate cyclase and GTP into cGMP, which leads to musclar relaxation of the corpora cavernosa and then erection

the “off” switch for this pathway converts cGMP into GMP using PDE5 the inhibtors block this “off” switch

Question 18

what are the pharmacokinetics of sildenafil (viagra)?

Answer 18

peak plasma concentrations at 1 hour - take 1 hour prior to intercourse

half-life 4 hours (short)

Question 19

what is the pharmacokinetics of Cialis (tadalafil)?

Answer 19

half-life is 18 hours (effective 36)

peak concentration is 1-6 hours

Question 20

what are the adverse effects of PDE5 inhibitors?

Answer 20

hyptension (average decrease 9/6)

common: headache, flushing, indigestion

less common: visual disturbance, actue hearing loss, nasal congestion, diarrhea, rash

Question 21

How are the PDE5 inhbitors metabolized?

Answer 21

CYP3A4

Question 22

what kind of hearing loss has been reported with PDE5 inhibitors?

Answer 22

unilateral, 1/3 temporary, sometimes with vertigo, tinnitus and dizziness

Question 23

what kind of reports of vision loss have there been with PDE5 inhibitors?

Answer 23

nonaerteritic ischemic optic neuropathy

progressive, usually after continual use

partial vision loss, but permanent

small # cases 15-20

Question 24

what are the potential serious interactions with nitrates for the PDE5 inihibitors?

Answer 24

large decrease in BP, syncope, lower cardiac perfusion, MI

don’t forget that nitrates includes nitroprusside and recreational drugs like amyl nitrate and butyl nitrate