Somatomotor penile innervation originates in Onuf’s nucleus in the S2-4 spinal segments. These nerves travel to the ischiocavernosus and bulbocavernosus muscles when activated lead to contraction necessary for the rigid-erection phase. Several animal studies show that stimulation of the somatomotor pathways may also be under sympathetic control, and adrenergic stimulation may lead to contraction of these muscles during ejaculation (13,14). Somatomotor spinal reflexes may also be initiated by genital stimulation. For instance, the well-known bulbocavernosus reflex is evidence this reflex exists; however the clinical significance of its absence in the neurological assessment of ED has not been substantiated (15).

Several pathways have been described to explain how information travels from the hypothalamus to the sacral autonomic centers. One pathway travels from the dorsomedial hypothalamus through the dorsal and central gray matter, descends to the locus ceruleus, and projects ventrally in the mesencephalic reticular formation. Input from the brain is conveyed through the dorsal spinal columns to the thoracolumbar and sacral autonomic nuclei.

Testosterone replacement therapy may improve energy, mood, and bone density, increase muscle mass and weight, and heighten sexual interest in older men who may have deficient levels of testosterone. Testosterone supplementation is not recommended for men who have normal testosterone levels for their age group due to the risk of prostate enlargement and other side effects. Testosterone replacement therapy is available as a cream or gel, topical solution, skin patch, injectable form and pellet form placed under the skin.


When other treatments haven’t helped, a penile implant may be the right solution. A penile implant is a medical device that is surgically placed into a penis to mimic the look and performance of a natural erection9. Implants are custom-fitted to your anatomy. Sensitivity and the ability to ejaculate aren’t typically affected either, so you’ll be able to have an orgasm normally (unless you have a medical condition that prevents this)7.
Occasional successful sexual function and early morning erections do not preclude the possibility of endocrine dysfunction. Since abnormally low levels of testosterone frequently are the primary cause of impotence, it is recommended that determination of the blood level of testosterone be an integral part of the total evaluation of the impotent patient.
If a trial of oral ED therapy and withdrawal of offending medications prove to be ineffective in restoring erectile function, it is appropriate for most primary care practitioners to consider referral to a specialist for additional evaluation and discussion of alternative treatment options. These include intracavernous injection therapy, vacuum constriction devices, intraurethral therapy, and possible surgery.
Unfortunately, some patients may have an overly simplified understanding of the role of PDE5 inhibitors in ED management. Such patients may not expect or be willing to undergo a long evaluation and testing process to obtain a better understanding of their sexual problem, and they may be less likely to involve their partner in discussing their sexual relationship with the physician. They may expect to obtain medications through a phone call to their doctor or even over the Internet, with minimal or no physician contact at all.
What are the alternatives to viagra? Erectile dysfunction, when a man cannot achieve or maintain an erection, is a common condition that causes much distress. Viagra is just one of several drug treatments that can help relieve the problem. Other methods and treatments can help, too, including alternative herbal remedies that people may wish to try. Read now
Positron emission tomorgraphy (PET), and functional magnetic resonance imaging (fMRI) have led to a greater understanding to which center are activated during arousal. These imaging studies measure increases in cerebral blood flow or changes in cerebral activity on a real-time basis. Studies are performed when male subject are aroused by visual cues (usually sexual explicit photos or videos) and compared to images obtained during exposure to sexually neutral cues differences can be measured. Several studies have identified that the inferior frontal lobes, inferior temporal lobes and insular gyrus, and occipital lobes are involved with processing arousal cues, although each are likely to process different stimuli (20-23).

The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina; it is now mostly replaced by more precise terms, such as erectile dysfunction (ED). The study of ED within medicine is covered by andrology, a sub-field within urology. Research indicates that ED is common, and it is suggested that approximately 40% of males experience symptoms compatible with ED, at least occasionally.[38] The condition is also on occasion called phallic impotence.[39] Its antonym, or opposite condition, is priapism.[40][41]
Organic ED involves abnormalities the penile arteries, veins, or both and is the most common cause of ED, especially in older men. When the problem is arterial, it is usually caused by arteriosclerosis, or hardening of the arteries, although trauma to the arteries may be the cause. The controllable risk factors for arteriosclerosis--being overweight, lack of exercise, high cholesterol, high blood pressure, and cigarette smoking--can cause erectile failure often before progressing to affect the heart. 
Certain types of blood pressure medications, antiulcer drugs, antihistamines, tranquilizers (especially before intercourse), antifungals (hetoconazole), antipsychotics, antianxiety drugs, and antidepressants, known as selective serotonin reuptake inhibitors (SSRIs, including Prozac and Paxil), can interfere with erectile function. Smoking, excessive alcohol consumption, and illicit drug use may also contribute. In rare cases, low levels of the male hormone testosterone may contribute to erectile failure. Finally, psychological factors, such as stress, guilt, or anxiety, may also play a role, even when the impotence is primarily due to organic causes.
Herbal supplements such as ginkgo biloba, saw palmetto, and yohimbe have been touted as sexual enhancers, and some men have been tempted to try them to treat erectile dysfunction. Bennett warns, however, that none has been approved by the FDA or even shown by any reliable studies to prevent, treat, or improve erectile dysfunction. Moreover, supplements are unregulated and can have many side effects or interfere with prescribed medications you’re already taking. Don’t jeopardize your health by taking a supplement to treat erectile dysfunction without first talking with your doctor.

Martha K Terris, MD, FACS is a member of the following medical societies: American Cancer Society, American College of Surgeons, American Institute of Ultrasound in Medicine, American Society of Clinical Oncology, American Urological Association, Association of Women Surgeons, New York Academy of Sciences, Society of Government Service Urologists, Society of University Urologists, Society of Urology Chairpersons and Program Directors, and Society of Women in Urology

Psychological Causes of ED – Between 10% and 20% of ED cases have a psychological cause. Because arousal starts in the brain, psychological issues can be a significant contributing factor to erectile dysfunction. Mental health conditions like depression or anxiety can negatively impact your libido, making it more difficult for you to become aroused.


Recently, the US Food and Drug Administration (FDA) has issued a safety announcement regarding TRT. In part it reads ‘The benefit and safety of these medications have not been established. We are also requiring these manufacturers to add information to the labeling about a possible increased risk of heart attacks and strokes in patients taking testosterone.’37
"Sexual relations are not only an important part of people's wellbeing. From a clinical point of view, the inability of some men to perform sexually can also be linked to a range of other health problems, many of which can be debilitating or potentially fatal," says Professor Gary Wittert, Head of the Discipline of Medicine at the University of Adelaide and Director of the University's Freemasons Foundation Centre for Men's Health.
Can’t or don’t want to take ED drugs? The vacuum pump method is the next most common choice among men with erectile dysfunction who pass on pills, says Dr. Bennett. To create an erection, you place a plastic cylinder over the penis and pump the air out of the cylinder to force blood to flow into the penis. An elastic ring that you slide onto the base of your penis holds the erection. This ED treatment device is effective for about 75 percent of men. Side effects include numbness, bruising, and weak ejaculation — and the ring must be removed after 30 minutes.
Also called vacuum devices, penile pumps are devices that are placed over the penis to draw blood into the shaft. Once the vacuum creates an erection, the retaining band is slid down to the lower end of the penis and the pump is removed. An erection typically will last long enough for intercourse but your penis may be cold to the touch and the rubber band may restrict ejaculation.22

In fact, one study showed that men who use these medications recreationally, when they’re not really needed, were more likely to develop psychological impotence! Therefore, instead of wasting money, risking one’s physical health and worsening one’s erectile function, men with psychological impotence should opt for treatment strategies that truly address the root of the trouble.
All NOS subtypes produce NO, but each may play a different biologic role in various tissues. nNOS and eNOS are considered constitutive forms because they share biochemical features: They are calcium-dependent, they require calmodulin and reduced nicotinamide adenine dinucleotide phosphate for catalytic activity, and they are competitively inhibited by arginine derivatives. nNOS is involved in the regulation of neurotransmission, and eNOS is involved in the regulation of blood flow.
3. An intact, anatomically correct penis; 25% of impotence may be psychologic or 'partner-specific', 25% has an organic component and 50% of impotence is organic in nature; in organic impotence, nocturnal penile tumescence is absent Management-surgical Microvascular surgery to bypass occluded vessels–most effective in younger ♂, penile prosthesis Management-medical Combined therapy with phentolamine and papaverine–self-injected by the Pt, wielding an erection of 1 hr's duration is useful for arterial, neurologic, psychogenic impotence; other therapies–zinc, bromocriptine–Parlodel, isoxsuprine-Vasodilan, Voxsuprine, nitroglycerine, yohimbine–Yocon, Yohimex Etiology Smoking, CAD, HTN, DM, medications–hypoglycemic agents, vasodilators, cardiac drugs, antihypertensives, anger and depression; it is inversely correlated to dehydroepiandrosterone, HDL-C, and an index of dominant personality Primary impotence Complete absence of successful sexual coupling Secondary impotence Priapism, penile plaques, Peyronie's disease; drugs linked to impotence: antihypertensives–eg, methyldopa, guanethidine, reserpine, clonidine, due to ↓ BP, antidepressants–eg, phenelzine, isocarboxazide, amitriptyline–causing altered moods and decreased libido, tranquilizers–eg, chlordiazepoxide and lorazepam, and the muscle-relaxing diazepam, cimetidine, which ↑ prolactin, and is associated with impotence and loss of libido. Cf Infertility, Orgasmic dysfunction.
All studies demonstrate a strong association with age, even when data are adjusted for the confounding effects of other risk factors. The independent association with aging suggests that vascular changes in the arteries and sinusoids of the corpora cavernosa, similar to those found elsewhere in the body, are contributing factors. Other risk factors associated with aging include depression, sleep apnea, and low HDL levels.

MSA is a neurodegenerative disease of undetermined etiology, where ED is an early prominent sign occurring in 40% of men at the time of diagnosis (46,47). ED occurs in the majority of patients and the exact cause of it is unknown (48). Like PD, MSA likely affects the dopaminergic pathways within the brain essential for arousal (49). Orthostatic hypotension (OH) as a causal factor has been refuted by evidence that sildenafil can overcome reduced filling pressures, and the ED usually precedes the development of OH (46,49,50). Similar to other neurologic disorders that lead to ED, other disease related factors such as psychosocial stress, the burden of chronic illness, changed appearance, fatigue, decreased fine motor movement of fingers, immobility and diminished self-esteem due to loss of independence may contribute as well (51).


The primary nerve fibers to the penis are from the dorsal nerve of the penis, a branch of the pudendal nerve. The cavernosal nerves are a part of the autonomic nervous system and incorporate both sympathetic and parasympathetic fibers. They travel posterolaterally along the prostate and enter the corpora cavernosa and corpus spongiosum to regulate blood flow during erection and detumescence. The dorsal somatic nerves are also branches of the pudendal nerves. They are primarily responsible for penile sensation. [10]

It appears that testosterone has NOS-independent pathways as well. In one study, castrated rats were implanted with testosterone pellets and then divided into a group that received an NOS inhibitor (L-nitro-L-arginine methyl ester [L-NAME]) and a control group that received no enzyme. [24] The castrated rats that were given testosterone pellets and L-NAME still had partial erections, a result suggesting the presence of a pathway independent of NOS activity.
5. Medline Plus. US National Library of Medicine. NIH National Institutes of Health. Drugs that may cause impotence (updated 21 Jan 2015). http://www.nlm.nih.gov/medlineplus/ency/article/004024.htm (accessed Nov 2016). myDr myDr provides comprehensive Australian health and medical information, images and tools covering symptoms, diseases, tests, medicines and treatments, and nutrition and fitness.Related ArticlesImpotence treatmentsIf you have impotence (erectile dysfunction), the treatment your doctor recommends will depend on thErectile dysfunction: visiting your doctorFind out what questions a doctor may ask when discussing erectile dysfunction (ED, or impotenceGum disease linked to erectile dysfunctionAdvanced gum disease (periodontitis) has been linked to an increased risk of erectile dysfunction, wPeyronie's diseasePeyronie’s disease is condition where a band of scar tissue forms in the penis, causing aAdvertisement
NO is produced by the enzyme NO synthase (NOS). [13] NOS plays many roles, ranging from homeostasis to immune system regulation. To date, 3 subtypes have been identified: nNOS, iNOS, and eNOS, which are produced by the genes NOS1, NOS2, and NOS3, respectively. This nomenclature is derived from the sources of the original isolates: neuronal tissue (nNOS), immunoactivated macrophage cell lines (iNOS), and vascular endothelium (eNOS). The subtypes are not, however, limited to the tissues from which they were first isolated.
Since the advent of PDE5i, many other selective and non-selective peripheral acting compounds have been developed or are in development. Avanafil has shown promising results in treating ED in post-prostatectomy patients with suspected cavernous nerve injury (111). Other PDE5i marked in Asia such as udenafil, and mirodenafil also effective at treating ED may minimize side effects due to shorter half-lives (112-114). Soluable guanylate-cyclase inhibitors and potassium channel activators are compounds that have induced erections in animal models but remain experimental requiring further investigation (115-117).
Watts and coworkers, in their review article, make several points about this ED/CAD nexus. Endothelial dysfunction is present in both CVD and ED, and is linked through the NO mechanism. The authors note that PDE5 inhibitors improve endothelial function and have a salutary effect on both CVD and ED. Both ED and cardiac disease respond to modifications in lifestyle as well as pharmacologic manipulation. These authors also report that the presence of ED gives the clinician an opportunity to assess CVD and prevention as well.20
Penile implants - are generally used if physical damage (like an accident) makes the anatomical parts needed for an erection not work. These are inserted by surgery and can provide a permanent treatment choice if others fail to work. The implants can be semi-rigid or inflatable. They can be pretty expensive and are not usually available on the NHS.
Physical causes may include the narrowing of the blood vessels caused by hypertension (high blood pressure), nutritional deficiencies, certain prescription treatments and medications for enlarged prostate or prostate cancer, excess drinking, obesity, heavy smoking, kidney issues, thyroid problems, hormonal changes due to aging, injury, or surgery, diabetes, and high cholesterol levels.
The severity of ED has been correlated with the extent of CVD. Banks et al reported that the risk of future CV events increased progressively according to ED severity.28 This was shown in both men with and without known CVD at baseline and after controlling for confounders. Solomon and colleagues found an inverse correlation between international index of erectile function (IIEF) scores and plaque burden seen on coronary angiography.29 In addition, Yaman et al demonstrated a significant correlation between ED severity on IIEF questionnaires and coronary artery calcification.30

Cosgrove et al reported a higher rate of sexual dysfunction in veterans with posttraumatic stress disorder (PTSD) than in veterans who did not develop this problem. [42] The domains on the International Index of Erectile Function (IIEF) questionnaire that demonstrated the most change included overall sexual satisfaction and erectile function. [43, 44] Men with PTSD should be evaluated and treated if they have sexual dysfunction.


								   Impotence, also known as erectile dysfunction or ED, is a very common problem, affecting up to half of 40-70 year old men in Australia.Treatment techniques for impotence have varied through the years, from external steel mechanical attachments, to static electricity attached to the penis and testicles, to simple aphrodisiacs such as oysters. Until as recently as 1970, erectile failure was almost always seen as being due to psychological causes and was usually treated with psychotherapy.Since then, the medical causes contributing to impotence have been recognised and the treatment of impotence has been revolutionised, providing a range of options which are far more acceptable and very much more successful.Treatment options for impotenceTreatment choices for erectile dysfunction include:medicines;self-injection therapy;devices such as vacuum pumps;penile implant surgery;hormone therapy; andcounselling.If you have erectile dysfunction, the treatment your doctor recommends will depend on the severity of symptoms and the underlying cause of your impotence.Your doctor will want to check that any conditions that could be contributing to or causing erectile dysfunction are being treated.Your doctor may also suggest that you make some lifestyle adjustments, such as:increasing the amount of physical activity you get;losing weight if you are overweight;reducing the amount of alcohol you drink;quitting smoking; andnot taking illicit drugs.These lifestyle recommendations can help improve impotence related to several causes and improve your health in general.Medicines for erectile dysfunctionThe first tablet available for erectile dysfunction, sildenafil (brand name Viagra), has been largely responsible for helping to bring the topic of erectile dysfunction out into the open. Similar medications — tadalafil (Cialis) and vardenafil ( Levitra) — are also available. These medicines all work in a similar way, although there is some difference in how long their effect lasts. Sildenafil, tadalafil and vardenafil belong to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors because they block the PDE5 enzyme.How do oral medicines help treat erectile dysfunction?PDE5 inhibitors help in the process of getting and keeping an erection by working on chemicals in the body that are involved in erections. These medicines work by stopping PDE5 from breaking down an erection-producing chemical called cyclic guanosine monophosphate (cGMP). cGMP helps to relax the smooth muscle cells in the penis's erectile tissue, allowing more blood to flow into the penis to cause an erection. When PDE5 is temporarily blocked by these medicines, it can’t break down the erection producing cGMP, so an erection can be achieved and maintained. PDE5 inhibitors can be used in the treatment of erectile dysfunction that is due to physical or psychological causes.Medications such as Viagra, Cialis and Levitra will work only if you are sexually stimulated. They are not aphrodisiacs and won’t increase your sex drive.Side effects of PDE5 inhibitorsSide effects of these medicines can include headaches, flushes, blocked nose, indigestion and dizziness.In rare situations, sildenafil and vardenafil can cause a distortion of vision or change in colour vision.Tadalafil has been associated with back pain.Who can take medicines for impotence?PDE5 inhibitors cannot be taken by all men, so your doctor will need to evaluate your suitability before prescribing either of these medications.Men taking nitrates (often used to treat angina) should never take phosphodiesterase type 5 (PDE5) inhibitors. PDE5 inhibitors should also not be taken with some medicines used to treat high blood pressure.PDE5 inhibitors may also not be suitable for men with certain heart conditions or low blood pressure. Check with your doctor to find out if this type of medication may be suitable for you.Self-injection therapySelf-injection therapy delivers a medicine called alprostadil (brand name Caverject), also known as prostaglandin E-1, to the erectile tissue of the penis. Prostaglandin E-1 occurs naturally in the body and helps increase the blood flow to the penis to cause an erection. Unlike the PDE5 inhibitors, alprostadil will cause an erection whether the penis is stimulated or not.Self-injection therapy is usually recommended if PDE5 inhibitor medicines are not suitable or have not been effective in the treatment of erectile dysfunction.How to use self-injection therapyAlprostadil is injected into either of the 2 cigar-shaped chambers of the penis known as the corpora cavernosa, which run along the length of the penis, one on either side. Your doctor or urologist (specialist in problems with male reproductive organs and the urinary tract) will give you instructions on how to do this.Alprostadil should produce an erection in 5 to 20 minutes and, generally, the erection will last for 30 to 60 minutes.You should not use alprostadil more than once in a 24-hour period, and you should use it no more than 3 times a week.Don’t try to use more than the recommended dose of alprostadil, as your erection may last longer than is medically safe.Who can use self-injection therapy?You should ask your doctor if alprostadil is suitable for you. Your doctor will also be able to tell you how much alprostadil to use, depending on your condition and whether or not you are taking any other medications, and also how to use alprostadil properly.People with certain illnesses, such as leukaemia and sickle cell anaemia, or who have a penile implant or Peyronie’s disease, where the penis may be scarred and produces erections that are not straight, should not use alprostadil.Men for whom sexual activity is not advised should not use alprostadil.Side effects of injection therapyThe most common side effects of alprostadil include pain in the penis or bruising in the penis at the site of injection. Fibrosis (the development of fibrous tissue) can also develop following injections into the penis.The most serious side effect is priapism (a persistent erection), which is a medical emergency. Your doctor will inform you of what to do if you have an erection that persists for 2 hours or more. It is very important that you follow your doctor’s instructions and inform them that you have experienced this side effect.Vacuum erection devicesVacuum erection devices work by creating a vacuum, which increases blood flow to the penis, producing an erection.The penis is lubricated and placed inside a hollow plastic chamber. Air is pumped out of the chamber, either manually or by a battery powered pump. This creates a vacuum which pulls blood into the penis to cause an erection. This takes about 5 minutes.Once the penis is erect, the man fits a rubber ring around the base of his penis to keep the blood trapped inside the penis when the cylinder is removed. After intercourse, the ring can be removed to return the penis to a limp state.Vacuum erection devices avoid surgery and can be used as often as required. However, they may be difficult to use, and many men and their partners feel they take much of the pleasure and spontaneity away from sexual activities. Vacuum pumps are not suitable for men who have problems with blood clotting, or blood disorders such as leukaemia.Penile implant surgery for impotencePenile implant surgery is not a common procedure but in some cases it may be the most appropriate treatment for erectile dysfunction.The procedure involves placing an implant inside the penis, along its length, so that it can become erect. The implant may be a pair of semi-rigid rods or a pair of inflatable cylinders.The inflatable implants allow the penis to look and feel limp (flaccid) or erect, depending on how much the cylinders are inflated. The cylinders in an inflatable implant are hollow, and the man gets an erection by squeezing a pump located in his scrotum to fill the cylinders with salt water (saline) stored in a reservoir implanted in his lower abdomen. A release valve drains the saline out of the cylinders and back into the reservoir.With the semi-rigid, malleable rod type of implant, the rods run along the length of the penis and can be bent upwards to produce an erect penis, or downwards when an erect penis is not required.Like all surgery, there are some risks, such as infection or bleeding. If you have had surgery and have severe pain, fever, swelling or excessive bleeding, you should contact your doctor as soon as possible.Vascular surgery for erectile dysfunctionIn cases where a man’s anatomy prevents blood flow into or out of the penis, vascular surgery may be an option. This treatment option is rarely recommended, and is usually only successful in younger men.If there is a blockage that prevents blood from flowing into the penis, a doctor may recommend an operation that bypasses the blocked blood vessels, using a length of vein or manufactured tubing, to allow more blood to flow into the penis and help produce an erection.If the problem is that blood leaks back out of the penis, this can be corrected by tying off the major veins that drain the penis, a procedure known as venous ligation.Hormone treatments for impotenceIn a small number of men, blood tests may show abnormally low levels of testosterone, the male sex hormone. In such cases your doctor might prescribe a course of testosterone injections or a testosterone implant. The supplements can help boost sex drive as well as increasing the ability to have erections. Testosterone gel or patches, applied daily to the skin, are another option.Complementary medicines for erectile dysfunctionThere is a lack of scientific evidence supporting the effectiveness of complementary therapies for the treatment of impotence.Always check with your doctor before taking any herbal medicines or supplements for impotence. These formulations may contain ingredients that can interact with other medicines or cause dangerous side effects.Counselling for men with impotenceErectile dysfunction often has physical causes, but sometimes there is a psychological basis for erection problems. Often this is a form of performance anxiety. A man may have had an episode of erectile dysfunction due to some passing cause like fatigue, stress, relationship difficulty or intoxication. This may have led to embarrassment or a feeling of failure. Even if the physical cause does not remain, future attempts to have sex may trigger memories of this embarrassment and acute anxiety that it will happen again. This anxiety itself is capable of causing erectile dysfunction, and so a man may get trapped in a self-reinforcing cycle of anxiety and erectile dysfunction. In these instances, seeing a GP, counsellor or psychologist can be very helpful.Stress, anxiety, depression and low self-esteem, in fact, almost all significant emotional problems, can have a major effect on sexuality. So do many chronic physical illnesses, even if they don't directly affect genital function. Counsellors and psychologists can assist with these and a wide range of other sexual and relationship problems and can also help female partners suffering from sexual problems. They are particularly skilled in helping patients to overcome guilt or anxiety relating to sexual abuse, and in helping couples to sort out relationship difficulties. Simple problems can be dealt with in a few visits, but more complex problems may require several months or even years of therapy.Your doctor may be able to recommend a psychologist or counsellor who specialises in sexual and relationship problems. Last Reviewed: 12 December 2016 

Since endothelial dysfunction, CVD and ED are closely associated in epidemiological studies, the question for clinicians is whether to recommend the man presenting with ED undergo a cardiovascular (CV) evaluation. Clearly, based on numerous studies, ED can be considered at least a ‘marker’ for possible further vascular disease or CVD.15 In their report, Vlachopoulos and coworkers make the point that the man presenting with ED, the clinician, is offered an opportunity to attempt to improve the health of the man by addressing lifestyle modification, and consider further vascular evaluation owing to the clear relationship between endothelial dysfunction, ED and CVD.19
Talk with your doctor about going to a counselor if psychological or emotional issues are affecting your ED. A counselor can teach you how to lower your anxiety or stress related to sex. Your counselor may suggest that you bring your partner to counseling sessions to learn how to support you. As you work on relieving your anxiety or stress, a doctor can focus on treating the physical causes of ED.
Psychosocial problems are important and may cause erectile dysfunction by themselves or together with other causes of erectile dysfunction, such as diabetes and heart disease. Relationships are complicated and many factors cause tensions, which can affect sexual relations. For some men, these problems can become ongoing and it can help to talk through the issue with a skilled counsellor. It is important to know that the longer erectile dysfunction is left untreated, the greater the effect on relationships. This is another reason why early treatment of erectile dysfunction is important.
Nearly every primary care physician, internist and geriatrician now understand that many older men retain an interest in sexual activity as they age. Some primary care physicians think that sexual potency in older men is the norm, and that if it is lacking, it is ‘all in the head.’ This viewpoint has not been supported by current literature. The Massachusetts Male Aging Study (MMAS) found that 52% of men between 40 and 70 years old reported having some form of erectile dysfunction (ED).1 The reality is that ED is a natural part of ageing and that the prevalence increases with age. In the MMAS, they found that roughly 50% of men at 50 years old, 60% of men at 60 years old and 70% of men at 70 years old had ED. Thus, nearly all men who live long enough should develop ED. The myths that surround the problems of impotence or ED confound the attempts of patients to receive treatment and the attempts of physicians to help them.1

Following a detailed discussion about the history of erectile dysfunction and its risk factors, your doctor will examine the testicles and penis to help determine the cause of erectile dysfunction. Your doctor will check reflexes and pulses in the area to see if problems with blood vessels or nerves are contributing to the erectile dysfunction. If necessary, your doctor will order tests to help diagnose erectile dysfunction.
The dorsal artery provides for engorgement of the glans during erection, whereas the bulbourethral artery supplies the bulb and the corpus spongiosum. The cavernous artery effects tumescence of the corpus cavernosum and thus is principally responsible for erection. The cavernous artery gives off many helicine arteries, which supply the trabecular erectile tissue and the sinusoids. These helicine arteries are contracted and tortuous in the flaccid state and become dilated and straight during erection. [9]
As with most other organ system in the human body, changes and loss of function is normal consequence of the ageing process. This is also true of the endocrine system, specifically the levels of testosterone production from the Leydig cells of the testicle. Accompanying the decrease in testosterone is a decrease in erections which also has a component in decrease in the blood supply to the penis making erection not as frequent and not as rigid compared with a young man’s erectile function. Although these changes are in itself not life threatening, they can impact a man’s relationship with his partner, and also ED may be a harbinger of other undiagnosed conditions such as coronary artery disease (CAD), hypercholesterolaemia or diabetes mellitus.6
In some cases, nocturnal penile tumescence testing is performed to find out whether the man has erections while asleep. Healthy men usually have about four or five erections throughout the night. The man applies a device to the penis called a Rigiscan before going to bed at night, and the device can determine whether he has had erections. (If a man is able to have normal erections at night, this suggests a psychological cause for his impotence.)
Usually there will not be a specific treatment that will lead to the improvement of erectile dysfunction. However, there are treatments that will allow erections to happen and can be used to allow sexual activity to take place. There are three main types of treatments: non-invasive treatments such as tablet medicines and external devices (e.g. vacuum device); penile injections; or for men who have not had success with other treatments, surgery may be an option.

Alprostadil injections, which produce an erection in five to 20 minutes that lasts for about an hour. Patients use a fine needle to inject alprostadil (commonly known by the brand names Caverject Impulse and Edex) into the base or side of the penis. Side effects can include bleeding or fibrous tissue formation at the injection site as well as prolonged erection, according to the Mayo Clinic.
Vardenafil and tadalafil belong to the same group of chemical compounds as sildenafil, namely phos-phodiesterase type 5 (PDE-5) inhibitors. Some men cannot benefit from sildenafil or the two newer PDE-5 inhibitors because they have low levels of nitric oxide. British investigators reported in late 2002 that three different types of compounds are being studied as possible medications for men with low levels of nitric oxide. They are Rho-kinase inhibitors, soluble guanylate cyclase activators, and nitric oxide-releasing PDE-5 inhibitors.
How men can improve their sexual performance Many men want to know how to enhance their own and their partners’ sexual satisfaction. However, placing too much emphasis on performance can lead to anxiety. Certain lifestyle changes can help to reduce sexual anxiety, improve erectile dysfunction, and increase stamina. In this article, we describe 13 methods to try. Read now
However, a review of a United Kingdom medical record database found no evidence that the use of 5-alpha reductase inhibitors independently increase the risk for ED. In 71,849 men with benign prostatic hyperplasia (BPH), the risk of ED was not increased with the use of finasteride or dutasteride only (odds ratio [OR] 0.94), or a 5-alpha reductase inhibitor plus an alpha blocker (OR 0.92) compared with an alpha blocker only. In addition, the risk of ED was not increase in 12 346 men prescribed finasteride 1 mg for alopecia, compared with unexposed men with alopecia (OR 0.95). The risk of ED did increase with longer duration of BPH, regardless of drug exposure. [48]
Recognized risk factors for ED include cardiovascular disease (CVD) (hypertension, atherosclerosis, and hyperlipidemia), diabetes, depression, alcohol use, smoking, pelvic/perineal surgery or trauma, neurologic disease, obesity, pelvic radiation, and Peyronie’s disease. One study suggested that the relationship between arterial disease and ED is very strong, with 49% (147 of 300) of patients with coronary artery disease noted on cardiac catheterization reporting significant erectile dysfunction.6 Endothelial dysfunction has been indicated as the pathophysiologic mechanism responsible for both CVD and ED.7 The Boston Area Community Health survey demonstrated a dose-response between smoking and incidence of erectile dysfunction.8 Animal studies have demonstrated both smooth-muscle disruption and decreased production of neural nitric oxide synthase in cigarette-exposed animals.9
One study by Palmer and colleagues evaluated sildenafil use in SB males with thoracic lesions (76). A prospective, blinded, randomized, placebo-controlled, dose-escalation, crossover study in 17 patients with SB and ED was performed. All study participates took sets of tablet in groups, two sets of placebo, one of 25 mg, and the last 50 mg. Overall response to the tablet sets was measured by IIEF response and self-report of erectile rigidity. Patients reported that taking 50 mg of sildenafil led to improved erections, duration of erections, frequency of erections and level of confidence compared to sildenafil 25 mg and more significantly compared to placebo. Of the five patients who reported side effects, two experienced mild hematological changes that reverted to baseline after study completion.
Before pursuing ED treatments, though, bear in mind that improving heart health by losing weight, eating a healthier diet, exercising more and quitting smoking typically enhances erectile performance as well as one’s overall health. In addition, sex therapy counseling sessions can often ease or eradicate ED symptoms, if the underlying cause is psychological in nature, says Drogo Montague, M.D., director of the Center for Genitourinary Reconstruction at the Cleveland Clinic. 

The somatosensory pathways for erections originate in the penile skin, glans and urethra. Glans afferent sensory free nerve endings are 10-fold more than their corpuscular receptors, and are derived from Aδ and unmyelinated C fibers. The nerve endings coalesce to form the dorsal penile nerve along with other sensory nerve fibers. Through the pudendal nerve they enter the S2-4 nerve roots to terminate on spinal neurons and interneurons. The dorsal nerve is not purely somatic, however. Nerve bundles within the dorsal nerve contain nitric oxide (NO) synthase, found typically in autonomic nerves, and stimulation of the sympathetic chain can leak to evoked potentials from the dorsal nerve and vice versa (10-12).


A cold slice of watermelon can do more than just satisfy thirst and hunger during the warm summer months; it can help with bedroom satisfaction. Citrulline, the amino acid found in high concentrations of watermelon, is found to improve blood flow to the penis. A 2011 study revealed men who suffered from mild to moderate ED and took L-citrulline supplementation showed an improvement with their erectile function and were very satisfied. Natural watermelon juice, or “nature’s Viagra,” can also be easier on the stomach, since taking pills like Viagra can cause nausea and diarrhea.
Effective treatment for erectile dysfunction is available, and for most men will allow the return to a fulfilling sex life. The side effects of the treatment for erectile dysfunction vary depending on the treatment that is used. Some may interrupt the spontaneity of sexual activity. For example, PDE-5 inhibitors typically need to be taken one hour before sex. Side effects may include headaches, indigestion, vasodilation, diarrhoea and blue tinge to vision. Other treatments such as penile injections may cause pain at the injection site, or an erection that will not go down. Treatment options need to be carefully discussed with your doctor to determine which one is best suited to you.
In 1983, Brindley injected the corpora of several SCI men with phentolamine (85). Two out of the three men had a sufficient erection produced. Since then multiple reports on the efficacy of intracavernosal therapy have been published using, phentolamine, papaverine, prostaglandin, vasoactive intestinal peptide (VIP), and these medications in combination (86-90). These medications have been found to be extremely effective for neurogenic ED due to their ability act locally and essentially bypassing neuronal pathways. Local therapies are usually considered second-line after PDE5i fail to elicit a desired response which can occur in about 25–30% of men with ED, in general (91). Furthermore, the locally delivered medications can be quite dangerous if not used appropriately as priapism and significant pain with injections can occur. These specific occurrences have been suggested as a reason for high discontinuation rates with intracavernosal therapy (92).
Watts and coworkers, in their review article, make several points about this ED/CAD nexus. Endothelial dysfunction is present in both CVD and ED, and is linked through the NO mechanism. The authors note that PDE5 inhibitors improve endothelial function and have a salutary effect on both CVD and ED. Both ED and cardiac disease respond to modifications in lifestyle as well as pharmacologic manipulation. These authors also report that the presence of ED gives the clinician an opportunity to assess CVD and prevention as well.20
However, a review of a United Kingdom medical record database found no evidence that the use of 5-alpha reductase inhibitors independently increase the risk for ED. In 71,849 men with benign prostatic hyperplasia (BPH), the risk of ED was not increased with the use of finasteride or dutasteride only (odds ratio [OR] 0.94), or a 5-alpha reductase inhibitor plus an alpha blocker (OR 0.92) compared with an alpha blocker only. In addition, the risk of ED was not increase in 12 346 men prescribed finasteride 1 mg for alopecia, compared with unexposed men with alopecia (OR 0.95). The risk of ED did increase with longer duration of BPH, regardless of drug exposure. [48]
Positron emission tomorgraphy (PET), and functional magnetic resonance imaging (fMRI) have led to a greater understanding to which center are activated during arousal. These imaging studies measure increases in cerebral blood flow or changes in cerebral activity on a real-time basis. Studies are performed when male subject are aroused by visual cues (usually sexual explicit photos or videos) and compared to images obtained during exposure to sexually neutral cues differences can be measured. Several studies have identified that the inferior frontal lobes, inferior temporal lobes and insular gyrus, and occipital lobes are involved with processing arousal cues, although each are likely to process different stimuli (20-23).

Research is mixed on the effectiveness of acupuncture as an erectile dysfunction cure, but one study published in November 2013 in the Journal of Alternative and Complementary Medicine found that acupuncture can be beneficial for men experiencing erectile dysfunction as a side effect of antidepressants, including selective serotonin reuptake inhibitors (SSRIs) and serotonin noradrenaline reuptake inhibitors (SNRIs).
In addition, when research has shown a nutrient such as zinc or niacin to improve sexual function, it's usually in people who are deficient in it. So, before you stock up on over-the-counter nutritional supplements for ED, speak with your doctor. He can test you for deficiencies and steer you toward the most effective and safest way to treat your erectile dysfunction. 
It is important for clinicians prescribing these drugs to make the patient aware of the action of the drugs especially the fact that they do not result in an immediate erection, and that they do not cause an erection without sexual stimulation. There is frequently a great expectation when men begin using these drugs and it is wise to temper their enthusiasm and explain they do not work immediately, and may not work every time, but also let the patient know that if these drugs do not work, there are other options.
The other 5 percent of prostheses are either pump devices in which the saline is permanently in the prosthesis, not in a separate reservoir (urologists may recommend this for men who have had multiple surgeries); or a pair of semi-rigid, malleable rods implanted in the penis, which render it hard at all times. The patient manually shifts the penis into an erect position for sex.
Qaseem, A., Snow, V., Denberg, T. D., Casey, D. E., Forciea, M. A., Owens, D. K., & Shekelle, P. (2009). Hormonal testing and pharmacologic treatment of erectile dysfunction: A clinical practice guideline from the American College of Physicians. Annals of internal medicine, 151(9), 639-649. Retrieved from http://annals.org/aim/article/745155/hormonal-testing-pharmacologic-treatment-erectile-dysfunction-clinical-practice-guideline-from
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