Erectile Dysfunction

Erectile Dysfunction

ED (aka impotence) is defined as “the persistent inability to achieve or sustain and erection sufficient for satisfactory sexual intercourse.”  This can be a total inability or inconsistent ability, or a tendency to sustain only brief erections.

Although it is common (at least 50% of men over 50 year old have some loss of function), it is NOT normal, no matter what the patient age.

Unfortunately, only 10% of men seek treatment and many (50%) discontinue treatment once they start it.  This is because they are understandably embarrassed to raise this issue with their physicians and they may get inadequate information about the many treatments that are available to them.

[pic of penis, permission from my chapter in Vascular Surgery]

It is even more unfortunate when you consider that it 1) affects the quality of life 2) makes men feel worse about their general health and 3) may be a symptom of an underlying disorder (for example, diabetes, cardiovascular disease, etc).  Men do not realize that there are a variety of very satisfying treatments and there is no need to suffer in silence.

We have written several more general textbook chapters on ED; for a more thorough discussion of these issues, please see [link to Endocrine chapter]


In the most basic analysis, an erection consists of blood flowing into the corpora cavernosa (AKA erection bodies) and being trapped there. [pic of venoocclusive mechanism]  A problem with either blood getting in or staying in causes ED.

Potential causes are many and include: vascular (high blood pressure, elevated cholesterol, diabetes, cardiovascular disease), diabetes, trauma (spinal cord injury or injury to the pelvis), neurologic disease (stroke, Parkinson’s disease), radiation to the pelvis (for prostate or rectal cancer), endocrine disease, surgery in the pelvis (radical prostatectomy, surgeries for rectal cancer or bladder cancer), medication side effects (especially medications used for high blood pressure), alcohol, tobacco, cocaine, etc.


This is a “couples disease”.  Even though the problem is not Psychologic (i.e. it’s not “all in your head”), ED causes depression, anxiety, loss of feelings of masculinity and self-esteem.  This of course affects relationships and may set up a “vicious cycle” where the partner feels unattractive and so stops initiating intimacy, the man then feels unattractive, etc.  This can be devastating to the couple.  Very few couples can or want to give up their physical intimacy without any problems!


Luckily, there are many good treatments.  These include pills [link], injections [link], penile suppositories [link], vacuum devices [link], and surgery [link].  Surgery provides the only cure but many men want to explore other options and may be very satisfied with them.


Currently, three pills are available (Viagra/sildenafil, Levitra/vardenafil, Cialis/tadalafil).  They are all “phosphodiesterase inhibitors” which means they act by blocking a chemical that stops erections.  Viagra was introduced in 1998 (the others in 2003) and revolutionized the way that men and their partners looked at ED.  With all the press and media coverage of these medications, men realized that they had a real problem and became more open to talking about it.


[link to handout on using PDE5i successfully]

These medications all act as “amplifiers”, meaning that men still need foreplay and erotic thoughts to have an erection.

The pills may not work the 1st few times, so it is worth trying the pills several times before deciding that they do or don’t work.

The pills (especially Viagra) should not be taken after a large meal, as they will not absorb as well.  They should be taken before a meal or after a snack.


Generally these medications are safe.  Side effects are common (around 30% of men have them) and include: headache, flushing (feeling hot), upset stomach, stuffy or runny nose, and back pain (especially Cialis).  Dr. Brant has written a review on the risk of blindness with using these pills [link to NAION article].

These medications should NOT be used if you are taking (or have at home) nitroglycerin or medications containing nitrates (ask your doctor or pharmacist if you have a question about this), as the combination may cause a dangerous drop in blood pressure.

These medications should be used with caution if you are taking medications for enlarged prostate (BPH) such as flomax/tamsulosin, hytrin/terazosin, etc.  Again, ask your doctor or pharmacist if you have questions about this or if you have any other less common medical conditions that would make you change the dosage of the pills.

You may hear about other pills that are available, such as yohimbine, Uprima, etc.  These are not approved by the FDA and generally are not very effective.

What if pills don’t work?

If pills don’t work or if the patient cannot tolerate them, alternatives include injections, suppositories, vacuum devices, or surgery.

What are vacuums?

A vacuum device (VED) is an external device (not a drug) that goes over the penis.  When pumped, it pulls blood into the penis then a special ring is placed over the base of the penis to keep it erect.

VED Pros Cons
Works well Cumbersome
No drug effects Unnatural erection
Cheapest option Bruising or burst blood vessels
Penile pain
Pain with ejaculation
“Hinging” or instability of erection
Penis may feel cold to partner
Poor overall satisfaction

VEDs are generally safe (although there have been some very rare but serious complications) but unfortunately many men simply do not like them.  They can only work well in the setting of a stable relationship and many men simply stop using them.


[pic from SMSNA slide set]

Although this information can be found in one our general articles on ED [link to Endrocrine chapter], we also can direct you to an article specifically on injections [link to Aging Health article]

Drugs may be injected directly (using a tiny needle) into the penis.  Several drugs and drug combinations are available, including alprostadil (Edex, Caverject), phentolamine, and papavarine (usually given in combination as Bimix or Trimix).  The patient can usually get an erection within 5-10 minutes and it should last between 20 minutes to an hour.

Injections do require training and it may be tricky to get the right dose.  We always do the first injection in clinic, which helps the patient learn to do it and also gives us a good idea about the dosing.  Patients are usually anxious about it but are almost always surprised by how painless the injection is.  The patient will be observed in clinic to make sure the erection goes down and, if necessary, the erection is reversed.  If needed, the patient returns another day to try a different dose; on the second trip, patients do the injection themselves under our supervision.  Some men do not require a second visit.

It is very important to alternate injecting the left and right side of the penis [link to diagram and info sheet] and to not use injections more than 3 times per week.


Very effective (85%) Risk of prolonged erection (“priapism”) [link to section]
Mimics normal erection Risk of penile scarring
Normal sensation, ejaculation Pain with injection (usually mild)
Discreet Bruising or bleeding
Hard to use if have tremor or poor vision or severe obesity
Poor long-term satisfaction (<40%)

Although injections often work well, long-term use is not common.



Urethral suppositories (AKA MUSE) contain alprostadil (see “Injections”).  The pellet is given via a delivery system into the urethra (urinary channel) and dissolves there.  Similar to injections, we always give the first suppository in clinic to make sure there are no problems and that the patient is comfortable doing this.

No needle Pain in penis (30%)
Mimics normal erection Expensive
Normal sensation, ejaculation Less effective than injections (50%)
Discreet Bleeding from urethra
Gives best erection to glans (head of penis) Hard to use if have tremor or poor vision or severe obesity
Rare scarring or prolong erection (“priapism”) [link to section] Poor long-term satisfaction (<40%)

Although the suppositories are appealing, effectiveness is relatively poor and overall satisfaction is relatively low.


Patients with diabetes know that diabetes is a very insidious disease, causing potential problems with almost all organ systems.  The penis is no exception.  Men with diabetes are much more likely than other men to have ED, and many men (around 10%) who come to a doctor with ED are found to have diabetes that they didn’t even know about!

Diabetes is particularly tough on the penis because it affects both nerves and blood vessels.  In many men with diabetes, there is also a lowered testosterone level [link to section].

Unfortunately, pills do not work as well in men with diabetes compared with other men with ED.  They are still worth trying.  Similarly, the other medications available for ED [links] are often not as effective in men with diabetes.  It is critical for men with diabetes to make sure their health is good, watch their blood sugars and blood pressure, not use tobacco, exercise, etc.

We have written several articles and book chapters on ED in diabetics [link to Aging Male article, Endotext chapter, abstract on use in transplant patients]


The nerves that are necessary for normal erection are located just next to the prostate.  Therefore, any treatment for prostate cancer can cause ED.  This includes surgery or any of the radiation or other approaches (external beam, IMRT, brachytherapy, cryotherapy, proton beam, etc).  Many men are now getting their prostate removed with the robotically-assisted approach (“Da Vinci”), but this approach certainly does not guarantee preserving erection function and most studies show that the rate of ED is the same if a man has the robotically-assisted approach or the traditional open approach.

Although the rate of ED is not as high as it was before the new techniques, very few men feel that they are as potent after treatment as they were before.  Some factors that determine the patient’s potency after treatment include their age, whether or not nerves could be spared, and their sexual function before the surgery.

Treatment for prostate cancer can also affect urinary control and we discuss this in the following [link to section].

There are many options for treatment of ED after treatment for prostate cancer. Pills do not work as well in men after treatment for prostate cancer compared with other men with ED.  They are worth trying, but many men go on to try injections [link], suppositories [link], and/or vacuum devices [link].  In men for whom these treatments do not work or are not satisfactory, a penile implant [link] is often the best choice.


Men with a variety of neurological diseases and injuries may suffer from ED.  However, it is treatable, particularly in men with spinal cord injuries.  Because the blood vessels are often normal, many men with ED and neurologic issues do very well with medications, suppositories, or injections. In men for whom these treatments do not work or are not satisfactory, a penile implant [link] is often the best choice.


Dr. Brant wrote a review of the current literature in 2009. [link] and a more thorough discussion of this topic may be found here.

Bicycling is a very popular recreational activity and means of fitness all over the world; it is low impact, low cost, and efficient.  Some people have proposed that bicycling is harmful for erections and there are many reports of ED resulting from bicycle injuries.  Overall, however, the cardiovascular benefits of bicycling outweigh the smaller risk of ED.  If a patient suspects that they may have ED from bicycling, they should make an appointment to see a Urologist.  ED resulting from bicycle saddles or injuries is treatable. [opt: One of the most important elements is a good fit on the bicycle.  Although of course this is critical for serious amateur and professional cyclists, studies suggest that it may be even more important for novice and intermediate cyclists.  There are several very experienced and “penis-savvy” professional fitters in our area.  We recommend Ryan Littlefield and his staff at The Contender [link to shop website], but there are other experienced fitters in the area.  Men from outside of the area should consider discussing this with their local bike shop to see who is recommended locally.