Erections also require neural input to redirect blood flow into the corpora cavernosae. Psychogenic erections secondary to sexual images or auditory stimuli relay sensual input to the spinal cord at T-11 to L-2. Neural impulses flow to the pelvic vascular bed, redirecting blood flow into the corpora cavernosae. Reflex erections secondary to tactile stimulus to the penis or genital area activate a reflex arc with sacral roots at S2 to S4. Nocturnal erections occur during rapid-eye-movement (REM) sleep and occur 3–4 times nightly. Depressed men rarely experience REM sleep and therefore do not have nocturnal or early-morning erections.

Some men should not take PDE5 inhibitors. They can cause hypotension (abnormally low blood pressure that can lead to fainting and even shock) when given to patients who are taking nitrates (medications taken for heart disease). Therefore, patients taking nitrates daily should not take any of the PDE5 inhibitors. Nitrates relieve angina (chest pain due to insufficient blood supply to the heart muscle because of narrowing of the coronary arteries); these include nitroglycerine tablets, patches, ointments, sprays, and pastes, as well as isosorbide dinitrate and isosorbide mononitrate. Other nitrates such as amyl nitrate and butyl nitrate also are in some recreational drugs called "poppers."


ED is common among patients with cardiovascular diseases (CVD). Sexual problems usually precede the onset of CVD, and should, therefore, be considered as a risk factor for cardiac events. Similarly, patients with preexisting CVD are at increased risk of experiencing ED. Therefore, ED and CVD might be considered as two different clinical manifestations of the same systemic disease.19
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.

Drinking in moderation can be beneficial to your heart health, and therefore your sex life. A 2004 study published in the journal Seminars in Vascular Medicine found moderate alcohol consumption was associated with decreased cardiovascular mortality due to the antioxidant capacities of alcoholic beverages. The polyphenolic compounds — a group of compounds that include tannins and anthocyanins — were shown to change the lipid profiles, decrease coagulation, increase fibrinolysis, inhibition of platelets, and increase nitric oxide. This is vital since vascular diseases (those that affect the blood vessels) commonly cause erectile dysfunction.


While these are the two most comparable datasets on this subject, there’s a problem with both of these studies, which is that they don’t tell us anything about the severity of the difficulties experienced. Having erectile “difficulty” doesn’t necessarily mean that these guys can’t get an erection at all or that they have problems every time and with every partner. Also, we don’t know whether guys who had very mild problems answered these questions consistently (e.g., if it only happened once or you didn’t think it was a big deal, would you still report it as a problem?).
Until recently, erectile dysfunction (ED) was one of the most neglected complications of diabetes. In the past, physicians and patients were led to believe that declining sexual function was an inevitable consequence of advancing age or was brought on by emotional problems. This misconception, combined with men’s natural reluctance to discuss their sexual problems and physicians’ inexperience and unease with sexual issues, resulted in failure to directly address this problem with the majority of patients experiencing it.
Many younger men are concerned that this will create a dependency on the medication.  However, you cannot become dependent because there is no tachyphylaxis to these medications.  This means, that unlike some other drugs (opiates, benzodiazepines) your body does not get used to these medications over time, so you won’t need to up the dosage over time to get the same effect.  In fact, we have found the opposite to be true.  Over time, many of our younger patients need less medication and need it less frequently.
Erectile dysfunction (ED) generally affects men older than 65, but younger men can get it too. If it happens at a younger age, ED may be a warning sign of another health issue. If you have no obvious risk factors and no other health problems, like diabetes, your doctor will run laboratory tests and may order heart tests. The same process that affects the arteries in the penis affects the ones in your heart, too. If something is wrong and it is not diagnosed and treated, you have a fairly high risk over the next four to five years of having some type of cardiac event.
These are among the most challenging patients seen in urology practice today: a young, healthy man with neither systemic disease nor a history of trauma, who has complaints of ED (Table 2). These men often have co-morbid diagnoses, such as anxiety, depression, or mood disorders, which make the issue of ED more complex for both the patient and the urologist (12). The psychological burden of ED in these young men is more pronounced than it might be in older men as this is the phase of life during which many men expect to be highly sexually active (4). These young men are usually technologically savvy and may have scrutinized much of the readily available information on the internet regarding ED. Often they arrive to clinic armed with an understanding of the diagnostic evaluation that may be offered to further investigate the etiology of their concerns. This makes the evaluation and treatment of these men more challenging since additional diagnostic testing is often not indicated after a thorough history and physical examination. In many cases, they may have self-diagnosed and self-treated based on the information that they obtained prior to seeing a physician. Many of these men will see multiple urologists on their quest to find a pathophysiology that they can accept, and many have unrealistic expectations of a rapid cure or a surgical cure.
Aging: There are two reasons why older men are more likely to experience erectile dysfunction than younger men. First, older men are more likely to develop diseases (such as heart attacks, angina, cardiovascular disease, strokes, diabetes mellitus, and high blood pressure) that are associated with erectile dysfunction. Second, the aging process alone can cause erectile dysfunction in some men by causing changes in the muscle and tissue within the penis.
This is a 17-year-old male with a past medical history of insomnia, anxiety and depression who presents with complaints of gradual onset (2 years ago) of decreased ability to obtain and maintain erections adequate for intercourse. He reports normal nocturnal erections “most days of the week”. He does not masturbate because he feels that masturbation may have desensitized his brain and caused ED; however, he can masturbate and have an erection with normal orgasm/ejaculation. He has had a successful erection and intercourse with a partner, last time 2 weeks ago. He feels that his ED might have been associated with SSRI treatment but noted no improvement after stopping his SSRI. Cialis 5 mg is effective. He reports normal libido “but not where it was”. His testosterone (T) and free T are normal. He is in the care of a sexual therapist and has read extensively on the internet. He takes trazodone nightly for sleep.
For oral erectile dysfunction medicines to work as desired, they must be used properly in the first place. This means taking the medicine 30–45 minutes before engaging in sexual intimacy; taking the drug on an empty stomach or at least avoiding a heavy or high-fat meal before taking the drug (this is especially important when using sildenafil); and engaging in adequate genital stimulation before attempting intercourse. Drinking small amounts of alcohol (one to two drinks) should not compromise the effectiveness of erectile dysfunction medicines, but larger amounts of alcohol can diminish a man’s ability to have an erection.
When sexually stimulated there is a release of a chemical, nitric oxide (NO) in the blood vessels of the corpus cavernosum. The NO stimulates the production of a compound called cGMP, which causes relaxation of the smooth muscle in the blood vessels supplying the corpus cavernosum. PDE 5 is an enzyme that breaks down cGMP. By inhibiting the breakdown of cGMP by PDE5, these medications allow cGMP to build up in the penis. cGMP causes muscles in the corpora cavernosa of the penis to relax. When the muscle is relaxed, more blood can flow into the penis and fill the spaces in the penis. As the penis fills with blood, the veins in the penis are compressed, and this results a hard erection. When the effect on PDE5 decreases, the cGMP levels go down and the muscle in the penis contracts, causing less blood to flow into the penis and allowing the veins to open up and drain blood out of the penis.
Many commonly used drugs can cause erectile dysfunction. Prescription medication and over-the-counter drugs can decrease libido, interfere with normal blood flow, or even cause absent seminal emission or retrograde ejaculation. In fact, 8 of the 12 most commonly prescribed medications list ED as a side effect. Medications that commonly cause ED include:

The study, led by the University of Exeter and the University of Oxford, looked at data on more than 220,000 men across three cohorts, 6,000 of whom experienced erectile dysfunction. The research echoed recent findings that erectile dysfunction has a genetic cause, and goes further by opening the possibility that living a healthier lifestyle may help reduce risk.


Dr. Jonas Bovijn is the co-first author of the study and is from the Big Data Institute at the University of Oxford. He said: “We know that there is observational evidence linking erectile dysfunction and type 2 diabetes, but until now there has not been definitive evidence to show that predisposition to type 2 diabetes causes erectile dysfunction.”
• Blood Vessels: Diabetes damages blood vessels, especially the smallest blood vessels such as those in the penis. Diabetes can also cause heart disease and other circulatory problems. Proper blood flow is absolutely crucial to achieving erection. “Erection is a hydraulic phenomenon that occurs involuntarily,” says Arturo Rolla, MD, of Harvard University School of Medicine. “Nobody can will an erection!” Anything that limits or impairs blood flow can interfere with the ability to achieve an erection, no matter how strong one’s sexual desire.
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