Chapter 69 Drugs for Erectile Dysfunction and Benign Prostatic Hyperplasia Flashcards
What is erectile dysfx (ED)?
Persistent inability to achieve or sustain an erection
suitable for satisfactory sexual performance normally associated with chronic illnesses
What is tx for ED?
Oral agents - Sildenafil (Viagra®)
Vardenafil (Levitra®, Staxyn®)
Tadalafil (Cialis®)
Non-oral agents- 2nd-line therapy
Papaverine plus phentolamine
Alprostadil (Prostaglandin E1) [Caverject®, Caverject Impulse®, Edex®,
Muse®]
Psychotherapy
Surgical implantation of penile prosthesis
Sildenafil (Viagra) is a Phosphodiesterase type 5 (PDE5) inhibitor - does what?
First oral agent for ED & only enhances normal erectile response in the presence of stimuli.
Can be dangerous if used concurrently with other vasodilators such as alpha adrenergic blockers and nitrates
Used originally to treat pulmonary arterial HTN
Sildenafil (Viagra®) a/e?
Hypotension
Dizziness, rash, mild transiet visual disturbances, sleep apnea intensification
Priapism - long lasting erection
Sildenafil (Viagra®) considerations? Drug interactions?
Absorption slowed by high fat meals
DI - nitrates - SEVERE hypotension, need 24 hrs in between med admin for safety THEY SHOULD NOT ALTERNATE DRUGS EVERY 24 HOURS!
Sildenafil (Viagra®) is used with caution in?
MI, stroke, and life-threatening dysrhythmia within the last 6 months
Resting hypotension (BP below 90/50 mm Hg)
Resting hypertension (BP above 170/110 mm Hg)
Heart failure
Unstable angina
PDE5s should not be taken with?
PDE5s should not be used at all by men
taking nitroglycerin or any other drug in the nitrate family!
Nitroglycerine, isosorbide mono and dinitrate
What does Vardenafil (Levitra®, Staxyn®) do?
PDe5 with similar MOA
Relaxes arterial and trabecular smooth mm. in the penis
Vardenafil (Levitra®, Staxyn®) drug interactions?
NITRATES!!!!!
Could cause life-threatening hypotension
Wait 24 hours in between taking these two medications!!
This is not to imply that you can take one drug today, the other tomorrow, the first drug the next day, etc.!
Tadalafil (Cialis®) is a PDE5 inhibitor that does what?
Relaxes penile arterial and trabecular smooth muscle
Effects last up to 36 hours-much longer than with sildenafil or vardenafil;
therefore, timing of dosing and sexual activity need not be tightly coupled (no pun
intended!
Tadalafil (Cialis®) adverse effects? Drug interactions?
Headache, dyspepsia, back pain, myalgia, limb pain, flushing, & nasal congestion
Sudden hearing loss and vision loss from nonarteric ischemic optic neuropathy
NITRATES, alpha blockers (except tamsulosin)
Papaverine is what? Phentolamine is what? What do these medications do? Admin?
Smooth mm. relaxant and phentolamine is a alpha blocker)
Increase arterial flow; decrease venous flow by injection straight into the corpus cavernosum… ouch
Alprostadil (prostaglandin E1) is administrated? Frequency?
Injection and also increase arterial blood flow and reduces venous flow, no more than 3x a week
ransurethral—alprostadil pellets (Muse®) is administered how?
a pellet is placed into a small plastic applicator, which is then inserted 1.5 inches into the
urethra - does not cause penile fibrosis
What is benign prostatic hyperplasia (BPH)?
Nonmalignant prostate enlargement leading to s/sx of urinary problems
What are tx modalities for BPH? Specific obstructions?
Drug therapy
5-Alpha-reductase inhibitors (mechanical obstruction –> large prostate)
Alpha1-adrenergic antagonists (dynamic obstruction –>
increased muscle tone)
Finasteride (Proscar) does what? A/e?
Most effective in patients with a very large prostate (mechanical
obstruction)
Decreases levels of prostate specific antigen (PSA)
Dutasteride (Avodart) similar to Finasteride but with what differences?
Reduction in circulating DHT is more complete
Harmful to developing male fetus + pregnant woman
Long half life (5 weeks)
When screening for prostates cancer with PSA, what should you be looking for?
When screening for prostate cancer with PSA
* After one year of 5-ARI use, the reported of PSA level should be increased by a
factor of 2 when comparing with normal reference values
* After two or more years of 5ARI use, the reported PSA level should be increased by
a factor of 2.5 when comparing with normal reference values
Should you use older or new alpha1 adrenergic antagonist?
Older - Terasozin, Doxazosin
Newer - Tamsulosin, Alfuzosin, Silodosin
They have not been compared to see if one is more effective than the other but the newer agents mat be better tolerated than the older medication
When would you use an alpha 1 adregnergic antagonist med?
Preferred for men with relatively small prostates (dynamic
obstruction)
Do not decrease the size of the prostate like the 5-alpha-reductase
inhibitors may do.
What medication is most useful for patients who have both HTHN and BPH?
NEWER A1 Blockers!
Alfuzosin (Uroxatral®), terazosin (Hytrin®) & doxazosin (Cardura®)
Nonselective alpha1 blockers
Block alpha1 receptors in the blood vessels PLUS alpha1a receptors in the prostate
Promote vasodilation and can lower blood pressure
Very useful for patients with both HTN & BPH!!
What are general a/e for A1 blockers?
Generally well tolerated, BUT
they have minimal effects on vascular smooth mm.
DO NOT decrease PSA LEVELS!
What is Floppy Iris Syndrome?
Is a complication of cataract surgery seen with use of tamsulosin that can increase
postoperative pain, delay recovery, and reduce the hoped-for improvement in vision acuity. In severe cases, the syndrome can cause
defects to the iris that may lead to blindness.
Anticipated cataract surgery is not an absolute contraindication for tamsulosin use. Men anticipating cataract surgery should postpone initiation of alpha blocker therapy until after the procedure if possible.
Men already taking an alpha blocker should be sure to tell their ophthalmologist. This will allow for modifications to the surgical technique
during the procedure.
