Jump up ^ Reepmeyer JC, Woodruff JT (2007). "Use of liquid chromatography-mass spectrometry and a chemical cleavage reaction for the structure elucidation of a new sildenafil analogue detected as an adulterant in an herbal dietary supplement". Journal of Pharmaceutical and Biomedical Analysis. 44 (4): 887–93. doi:10.1016/j.jpba.2007.04.011. PMID 17532168.
Medications: Many common medicines produce erectile dysfunction as a side effect. Medicines that can cause erectile dysfunction include many used to treat high blood pressure, antihistamines, antidepressants, tranquilizers, and appetite suppressants. Examples of common medicines that can cause erectile dysfunction include propranolol (Inderal) or other beta-blockers, hydrochlorothiazide, digoxin (Lanoxin), amitriptyline (Elavil), famotidine (Pepcid), cimetidine (Tagamet), metoclopramide (Reglan), naproxen, indomethacin (Indocin), lithium (Eskalith, Lithobid), verapamil (Calan, Verelan, Isoptin), phenytoin (Dilantin), gemfibrozil (Lopid), amphetamine/dextroamphetamine (Adderall), and phentermine. Prostate cancer medications that lower testosterone levels such as leuprolide (Lupron) may affect erectile function. Some chemotherapies such as cyclophosphamide (Cytoxan) may affect erectile function.

Men with a rare heart condition known as long QT syndrome should not take vardenafil since this may lead to abnormal heart rhythms. The QT interval is the time it takes for the heart's muscle to recover after it has contracted. An electrocardiogram (EKG) measures the QT interval. Some people have longer than normal QT intervals, and they may develop potentially life-threatening abnormal heart rhythms, especially when given certain medications. Men with a family history of long QT syndrome should not take vardenafil, as it is possible to inherit long QT syndrome. Furthermore, vardenafil is not recommended for men who are taking medications that can affect the QT interval such as quinidine (Quinaglute, Quinidex), procainamide (Pronestyl, Procan-SR, Procanbid), amiodarone (Cordarone), and sotalol (Betapace).
If surgical intervention is an acceptable option, the work-up then proceeds with a noctural penile tumescense (NPT) test, the single most valuable study to establish the diagnosis of organic impotence. The NPT test exploits the fact that males from birth to old age normally have erections during rapid eye movement (REM) sleep. Psychogenic impotence is associated with normal erections during sleep. In organic impotence there should be no evidence of erection or, if erections are present, they should be limited and poorly sustained.
Half of all men between the ages of 40 and 70 will experience erectile dysfunction. While the problem doesn't cause heart disease, the two often occur together – study after study has shown that men with ED are dramatically more likely to develop heart disease and have a heart attack or stroke. One German study from 2010 found men with erectile dysfunction are twice as likely to die within the next two years as those without, prompting some experts to call the phenomenon "the canary in the trousers".

Many common medications for treating hypertension, depression, and high blood lipids (high cholesterol) can contribute to erectile dysfunction (see above). Treatment of hypertension is an example. There are many different types (classes) of medications for high blood pressure; these include beta-blockers, calcium channel blockers, diuretics (medications that increase urine volume), angiotensin converting enzyme inhibitors (ACE inhibitors), and angiotensin receptor blockers (ARBs). Patients may use these medications alone or in combination to control blood pressure. Some of these medications can cause troubles with erections. For example, Inderal (a beta-blocker) and hydrochlorothiazide (a diuretic) cause erectile dysfunction, while calcium channel blockers and ACE inhibitors do not seem to affect erectile function. On the other hand, other medications (such as angiotensin receptor blockers [ARB] including losartan [Cozaar] and valsartan [Diovan]) may actually help with erections. Therefore, if possible, you may benefit from changing your medications, but this requires approval by your prescribing health care provider.
Penile blood flow is measured using a Doppler probe and a 2.5 cm blood pressure cuff. Systolic pressures in the right and left corpora cavernosa are measured and the penile–brachial index is calculated taking a ratio of penile systolic pressure to brachial systolic pressure. These measures should be repeated before and after 3 minutes of exercising the pelvic and leg muscles. In normal men, the PBI should be 0.9 or greater. Ratios between 0.7 and 0.9 suggest vascular impotence; a ratio below 0.6 is diagnostic. Pelvic arteriography can be done if revascularization is considered.
There are many effective treatments for impotence. The most popular is a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors. These include sildenafil (Viagra), vardenafil (Levitra), tadalafil (Cialis) and avanafil (STENDRA). These drugs are taken in pill form. They work in most men. But they are less effective in men with neurological causes of impotence.
Erectile dysfunction affects millions of men. Although for some men erectile function may not be the best or most important measure of sexual satisfaction, for many men erectile dysfunction creates mental stress that affects their interactions with family and associates. Many advances have occurred in both diagnosis and treatment of erectile dysfunction. However, its various aspects remain poorly understood by the general population and by most health care professionals. Lack of a simple definition, failure to delineate precisely the problem being assessed, and the absence of guidelines and parameters to determine assessment and treatment outcome and long-term results, have contributed to this state of affairs by producing misunderstanding, confusion, and ongoing concern. That results have not been communicated effectively to the public has compounded this situation.
Damage to the autonomic pathways innervating the penis may eliminate "psychogenic" erection initiated by the central nervous system. Lesions of the somatic nervous pathways may impair reflexogenic erections and may interrupt tactile sensation needed to maintain psychogenic erections. Spinal cord lesions may produce varying degrees of erectile failure depending on the location and completeness of the lesions. Not only do traumatic lesions affect erectile ability, but disorders leading to peripheral neuropathy may impair neuronal innervation of the penis or of the sensory afferents. The endocrine system itself, particularly the production of androgens, appears to play a role in regulating sexual interest, and may also play a role in erectile function.
What to do: Close your eyes and relax. If you're overly nervous, you may have triggered your sympathetic nervous system, the so-called "fight or flight" reaction your body has in intense situations. This can prevent you from having an erection for between five and 15 minutes. So go back to the foreplay stage. Kiss passionately. Caress. Perform oral sex. Don't rush things. Let your instinct take over. Remember; she's a person, just like you. 

Erythrocytosis has been noted in men on TRT, and should be monitored every 6–12 months depending upon the patients’ response to changes in haematocrit levels. For mild elevations, the dosage of testosterone can be decreased or the interval of using the medication can be increased. With the haematocrit greater than 50%, decisions to temporarily discontinue the medication or periodic phlebotomy may be indicated.38


Thanks for your question, Frightened Turtle! To help answer it, we spoke with Dr. Darius Paduch, urologist and male sexual medicine specialist at New York Presbyterian/Weill Cornell Medical Center, and sex therapist Jenni Skyler, Ph.D., director of The Intimacy Institute for sex and relationship therapy in Boulder, Colorado. Here's what they had to say:

In this study, ED proceeded CVD in almost 70% of cases. Similarly, many men with ED have been found to have pre-existing CVD. A study by Vlachopoulos et al evaluated the incidence of asymptomatic CVD in 50 men with ED.22 These authors found that 19% of men with ED had asymptomatic CVD. Similarly, Mulhall and colleagues found that 20% of men presenting with ED and vascular insufficiency on penile duplex had asymptomatic CVD.23
What happens is that the blood vessels of the penis are rather small, and a small amount of plaque in the penile arteries is going to result in erectile dysfunction. You need more plaque before the person’s actually symptomatic from a heart problem, but they’re linked. And so when anybody, any man has an erectile issue, it’s incumbent upon the physician to make certain that their cardiac status is healthy.
Erectile dysfunction affects millions of men. Although for some men erectile function may not be the best or most important measure of sexual satisfaction, for many men erectile dysfunction creates mental stress that affects their interactions with family and associates. Many advances have occurred in both diagnosis and treatment of erectile dysfunction. However, its various aspects remain poorly understood by the general population and by most health care professionals. Lack of a simple definition, failure to delineate precisely the problem being assessed, and the absence of guidelines and parameters to determine assessment and treatment outcome and long-term results, have contributed to this state of affairs by producing misunderstanding, confusion, and ongoing concern. That results have not been communicated effectively to the public has compounded this situation.
Additionally, the physiologic processes involving erections begin at the genetic level. Certain genes become activated at critical times to produce proteins vital to sustaining this pathway. Some researchers have focused on identifying particular genes that place men at risk for ED. At present, these studies are limited to animal models, and little success has been reported to date. [4] Nevertheless, this research has given rise to many new treatment targets and a better understanding of the entire process.
ED is defined as the inability to achieve a full erection or the inability to maintain an erection adequate for sexual intimacy. Other types of sexual dysfunction such as premature ejaculation and low libido may occur; however, the most common and disruptive problem in men is ED. Although most men will experience periodic episodes of ED, these episodes tend to become more frequent with advancing age.
Endocrine problems, though uncommon, should be considered in patients presenting with impotence. As a rule, impotence due to hypogonadism will be partial and accompanied by decreased libido. Hypothalmic–pituitary problems, which include tumors, are the most common endocrine disorders causing impotence, followed by primary gonadal failure from one of many causes. Poorly controlled diabetes with polyuria and polydypsia is an important reversible cause of impotence, as is hyperthyroidism. Certain drugs, alcohol included, can lead to impotence as a result of endocrine disturbances.
The pathogenesis of organic ED is related to dysfunction of the endothelium. Endothelial cells can become injured through a variety of mechanisms, most of which cause oxidative stress on the tissues. Many of these causes of oxidative stress are related to lifestyle issues which lead to hypertension, diabetes and dyslipidaemia (figure 1). Endothelial cell dysfunction results in reduction of endothelium-dependent vasorelaxation as well as increased adhesion of leukocytes to the endothelium. Endothelial cell injury then leads to a variety of sequelae, including ED, other types of vasoconstriction, atherosclerosis and thrombus formation.18
Vacuum devices for ED, also called pumps, offer an alternative to medication. The penis is placed inside a cylinder. A pump draws air out of the cylinder, creating a partial vacuum around the penis. This causes it to fill with blood, leading to an erection. An elastic band worn around the base of the penis maintains the erection during intercourse.
×