Erectile dysfunction Flashcards
Erectile dysfunction is likely a result of…
concurrent medical conditions that impair systems necessary for penile erection
Loss of libido may indicate?
androgen deficiency
Loss of erections may result from?
arterial/venous, neurogenic, hormonal, or psychogenic causes
What are Risk factors for erectile dysfunction
HTN Hyperlipidemia DM metabolic syndrome smoking chronic ethanol abuse psychological etiologies
Which medications can lead to erectile dysfunction?
anticholinergic agents dopamine antagonists estrogens, antiandrogens cns depressants agents that decrease penile blood flow BPH tx (finasteride, dutasteride) HLD tx (gemfibrozil) opiods
What are types of sexual dysfunction in men?
increased/decreased libido erectile dysfunction delayed ejaculation retrograde ejactulation infertility
Role of PNS and SNS in stimulation of the penis?
“point and shoot”
Parasympathetic - erection
Sympathetic - ejaculate
specific tx is first initiated with…
the least invasive forms of tx
Goal of tx for ED
restore the quality of the erection and satisfy the pt/partner
how do Vacuum erection devices work and who are they most effective for?
have slow onset of action (30 mins) and are not discreet
couple in a stable relationship
What are oral agents used in ED?
PDE inhibitors: Sildenafil (Viagra) Tadalafil (Cialis) Vardenafil (Levitra) Avanafil (Stendra)
Yohimbine (Aphrodyne, Yocon, tree bark) - available OTC
Trazodone (Desyrel)
ADE’s of Yohibine (Aphrodyne, Yocon, Yohimex, tree bark)
anxiety, insomnia, tachycardia, hypertension
Which drugs are convenient and effective regardless of the etiology of erectile dysfunction?
phosphodiesterase inhibitors
phosphodiesterase inhibitors fail in which % of pts??
30-40%
Contraindications for phosphodiesterase inhibitors
in pt’s taking any dosage formulation of nitrate
FYI: cGMP is involved in which 2 systems and which drugs work
lungs (bronchodilation)
mass cell degradation
anticholinergics (atrovent, ipotroprium)
How does phosphodiesterase isoenzyme Type 5 work and where is it found?
decreases catabolism of cGMP
genital tissue
also, peripheral vascular tissue, tracheal smooth muscle, platelets
where is PDE isoenzyme type 6 found? MC side effects and drug assoc. w/?
Rods and cones of the eye
blurred vision and cyanopsia (tinted blue)
MC w/ Sildenafil
Where is phosphodiesterase isoenzyme type 11 found and which drug is MC?
striated muscle
Tadalafil
PDE isoenzyme type 11 is assoc. with?
myalgia and muscle pain
PDE 5 Dosing instructions for Sildenafil (viagra) and vardenafil (levitra)
food decreases absorption by 1 hour
PDE 5 Dosing instructions for Tadalafil (cialis)
food does not affect rate or extent of drug absorption,
when taken w/ large amount of ethanol may cause orthostatic hypotension
PDE 5 Dosing instructions for Avanafil (stendra)
may be taken with food, when taken w/ large amount of ethanol may cause orthostatic hypotension
Which drug is not recommended in ED for a pt with severe hepatic impairment?
Tadalafil (cialis)
Eating a fatty meal decreases rate of oral absorption of which 2 PDE inhibitors?
Sildenafil (viagra)
vardenafil (levitra/staxyn)
Which drugs interact with Sildenafil, vardenafil, and tadalafil by causing a rise in serum levels unless you reduce the dose?
any potent cytochrome P450 34A inhibitor
ie. Cimetidine, erythromycin, clarithromycin, ketoconzaole, itraconazole, ritonavir, and saquinavir
Tadalafil doses are reduced only when the drug is used w/
most potent cytochrome P450 3A4 inhibitors
ie. Ketoconazole, Ritonavir
MC ADE’s for PDE 5 inhibitors?
Headache facial flushing dyspepsia nasal congestion dizziness
What is the most worrisome ADE for PDE Inhibitors?
Nonarteritic anterior ischemic optic neuropathy
- sudden, unilateral, painless blindness, which may be irreversible
Which pt’s are at risk for Nonarteritic anterior ischemic optic neuropathy
glaucoma, macular degeneration, DM retinopathy
HTN
undergone eye surgery or have experienced eye trauma
pts age 50 y/o or greater
smokers
Low back pain is unique to which PDE Inhibitor?
Tadalafil (cialis)
Which ADE is unique to vardenafil?
prolongation of the QT interval
Which 2 drugs have a shorter plasma half live making it more assoc. w/ priapism?
Sildenafil and vardenafil
Tx for priapism
- oral pseudoephedrine 60-120mg orally
- aspiration of the corpus cavernosum and intracavernous injection of alpha-andrenergic agents or methylene blue
- phenylephrine, epi, or methylene blue may be instilled into the corpus cavernosa
Which drugs interact with PDE and what can it cause?
organic nitrates
severe hypotension
increase tissue levels of cGMP
also angina tx (CCB, morphine, adrenergic antagonist)
Serum testosterone levels decrease starting at what age and rate?
40y/o
~10% per decade after
Symptoms of decreased testosterone?
decreased libido, ED, gynecomastia, small testes, reduced growth of body hair and beard, decreased muscle mass, increased body fat
untreated decreased testosterone may cause –>
anemia and osteoporosis
What time of day should you collect serum testosterone concentrations and what should you order with it?
8am
serum luteinizing hormone (LH)
T or F: Testosterone replacement regimens directly correct erectile dysfunction?
FALSE. improves libido therby correcting 2ndary ED
Testosterone replacement regimens should never be administered to..
men with normal serum levels
pts asxs w/hypogonadism
pts w /isolated ED as only sign hypogonadism
Oral testosterone supplements (Methyltestosterone and fluoxymesterone) are not recommended for use in…
pt’s with hepatotoxicity
What is important about dosing testosterone buccal system (striant)
time the dose so that buccal system is removed before every am and evening toothbrushing
do NOT chew or swallow
Testosterone cypionate IM injection (depo-testosterone) Contraindicated in…
pts w/severe hepatic or renal impairment
Testosterone cypionate IM injection (depo-testosterone) side effects
mood swings
What pt. education should you give pt on testosterone transdermal patch (androderm)
avoid swimming, showering, or washing administration site for 3 hrs after patch application
Where should you apply the transdermal testosterone supplement - androgel 1.6%?
to shoulders and upper arms
Where should you apply the transdermal testosterone spray (fortesta)?
front and inner thighs
Pt education for Testosterone transdermal solution (axiron)?
limit application to axilla
apply antiperspirant or deodorant before axiron
Who should administer testosterone subQ implant pellet (testopel)
trained health professional
Pt education for testosterone subQ implant pellet (testopel)
clinical onset is delayed for 3-4 months after initial dose
ADE’s of oral testosterone?
hyperlipidemia
sodium retention
*NOT a good choice!!
ADE’s of oral alkylated androgens?
hyperlipidemia
sodium retention
*Hepatoxicity
Intramuscular testosterone cypionate or enanthate ADE’s
mood swings, gynecomastia, polycythemia, hyperlipidemia
What is the only testosterone replacement regimen that does not achieve serum testosterone concentrations in normal range?
Oral testosterone
Testosterone subcutaneous implant ADE’s
pellet can be extruded accidentally (loss of drug effect)
Buccal system ADE’s?
gum irritation, bitter taste
Which testosterone replacement regiment achieves normal range of serum testosterone, circadian pattern, and androgen metabolites?
Transdermal gel
T or F: Alprostadil intracavernosal injections and intraurethral pellets are effective independent of etiology of erectile dysfunction? How many fail tx?
Trueee
1/3 of pt’s
Who administers Alprostadil?
the pt.
intracavernosal injection and intraurethral pellets
What is an example of an intraurethral drug?
Alprostadil (MUSE)
What are examples of intracavernosal agents?
Alprostadil (Caverject and Edex)
Papaverine
Phentolamine
MOA of Alprostadil – Prostaglandin E1 (Caverject and Edex intracavernosal?
causes smooth muscle relaxation of the arterial blood vessels and sinusoidal tissues in the corpora –> enhanced blood flow to and blood filling of the corpora
How long does the erection last with Alprostadil – Prostaglandin E1 (Caverject and Edex intracavernosal?
no longer than 1 hour
directly related to the dose
What is the efficacy of Alprostadil – Prostaglandin E1 (Caverject and Edex intracavernosal?
70-90%
T or F: Intraurethral Alprostadil (MUSE) can be combined with VED?
trueeee
Pt education of Intraurethral Alprostadil (MUSE)
administer 5-10 mins before sexual intercourse
empty bladder beforehand, voiding completely
what is Penile prothesis?
surgical insertion of a prothesis is most invasive tx of ED
Which PDE lasts 24-36 hours and inhibits PDE-11?
Tadalafil (Cialis)
Which PDE does not have an active metabolite?
Tadalafil (Cialis)
