The common PDE5 inhibitor drugs approved in the United States are sildenafil (Viagra), vardenafil (Levitra and Staxyn, the generic form), tadalafil (Cialis), or avanafil (Stendra). All of the currently approved PDE5 inhibitors work in the same way. They differ in the number of available doses, how quickly they work and last in your system, the dosing, and to some extent in the side effects. However, they generally share the same indications and contraindications. Currently, tadalafil is the only medication that patients can take on a daily basis and is approved for the treatment of both ED and BPH (benign enlargement of the prostate).
Alprostadil may also be administered into the urethral opening of the penis. In MUSE (medical urethral system for erection), the man inserts a thin tube the width of a vermicelli noodle into his urethral opening and presses down on a plunger to deliver a tiny pellet containing alprostadil into his penis. The drug takes about 10 minutes to work and the erection lasts about an hour. The main side effect is a sensation of pain and burning in the urethra, which can last about five to 15 minutes.
Sexual stimulation causes the release of neurotransmitters from cavernosal nerve endings and relaxation factors from endothelial cells lining the sinusoids. NOS produces NO from L-arginine, and this, in turn, produces other muscle-relaxing chemicals, such as cGMP and cyclic adenosine monophosphate (cAMP), which work via calcium channel and protein kinase mechanisms (see the image below). This results in the relaxation of smooth muscle in the arteries and arterioles that supply the erectile tissue, producing a dramatic increase in penile blood flow.
Can apple cider vinegar treat erectile dysfunction? Apple cider vinegar is thought to have many health benefits, but can it help treat erectile dysfunction (ED)? ED can result from cardiovascular problems, diabetes, and other factors. Apple cider vinegar may help improve symptoms of conditions related to ED. Find out how it may help, and how to use it safely. Read now
A CVA can occur anywhere through the brain, midbrain, brainstem and spinal cord leading to varying degrees of SD depending on location. A decline in libido, erection and ejaculation are frequent in men who have had a CVA, with a reported prevalence of ED that varies from 17% to 48% (28,29). Right hemispheric infarcts seem to affect erections more so than left-sided ones. The exact effects of CVA on sexual function are complex and multifactorial, as disability, psychological and emotional status can affect sexual function aside from the location of the CVA.
Cavallini, G., Modenini, F., Vitali, G., & Koverech, A. (2005, November). Acetyl-L-carnitine plus propionyl-L-carnitine improve efficacy of sildenafil in treatment of erectile dysfunction after bilateral nerve-sparing radical retropubic prostatectomy. Urology, 66(5), 1080-5. Retrieved from http://www.sciencedirect.com/science/article/pii/S0090429505006515
Many factors can contribute to sexual dysfunction in older men, including physical and psychological conditions, comorbidities and the medications used to treat them. Aspects of an ageing man’s lifestyle and behaviour and androgen deficiency, most often decreasing testosterone levels, may affect sexual function as well. A study of men between the ages of 30 and 79 years showed that 24% had testosterone levels below 300 ng/dL and 5.6% had symptomatic androgen deficiency.2
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
When lifestyle changes alone don’t work, drug therapy (Viagra®, Cialis®, Levitra®, etc.) is normally the next step. Most of these medications work similarly to enhance a natural chemical in your body that relaxes the muscles in your penis. The goal of this medication is to increase your response to sexual stimulation by increasing the blood flow in your penis allowing you to get an erection.22
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
Neurogenic ED remains difficult to diagnose and treat effectively. It is important to realize that many men with neurologic disorders may have ED related to disease related factors separate from the insult to the neuro-erectile pathway. These disease related factors must be addressed prior or simultaneously with pharmacologic and/or surgical therapy to effectively treat their SD. As awareness of the complexities of normal sexual function increase so will the recognition of SD in this population. This movement will lead to improved quality of life in men with neurologic disorders, as proven by the strong link between sexual function and quality of life.
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.  Nevertheless, this research has given rise to many new treatment targets and a better understanding of the entire process.
Modern drug therapy for ED made a significant advance in 1983, when British physiologist Giles Brindley dropped his trousers and demonstrated to a shocked Urodynamics Society audience his papaverine-induced erection. The drug Brindley injected into his penis was a non-specific vasodilator, an alpha-blocking agent, and the mechanism of action was clearly corporal smooth muscle relaxation. The effect that Brindley discovered established the fundamentals for the later development of specific, safe, and orally effective drug therapies.[better source needed][better source needed]
An analysis of 14 studies involving more than 90,000 patients with ED confirmed the relation between ED and an increased risk of cardiovascular events and mortality.  Compared with patients without ED, those with ED had a 44% increased risk of cardiovascular events, a 25% increased risk of all-cause mortality, a 62% increased risk of MI, and a 39% increased risk of cerebrovascular events. Treatment of ED, either through lifestyle interventions or by pharmacologic means, may improve prognosis and reduce risk.
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
Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older.  Testosterone is known to be important in mood, cognition, vitality, bone health, and muscle and fat composition. It also plays a key role in sexual dysfunction (eg, low libido, poor erection quality, ejaculatory or orgasmic dysfunction, reduced spontaneous erections, or reduced sexual activity). 
If you bike a lot and have a very narrow saddle on your bicycle, consider switching to a "no-nose seat" which is wider at the back than a conventional saddle, allowing more of your weight to be distributed to the sitting bones. Make sure the seat is level or angled slightly downward and at a height that allows your knee to be just slightly bent at the bottom of the pedal cycle. Raising the handlebars on your bike so that you're sitting upright may also help.
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.
PDE5i use in PD has not been well studied; however its benefits have been shown. Raffaele performed an open label, prospective study evaluating the efficacy of sildenafil 50 mg on demand and depressive symptoms experienced by the PD patient (73). Erections were improved in approximately 85% of men and 75% noted improvements in their depressive symptoms as well. Sildenafil was well tolerated without significant side effects. Zesiewicz et al., performed a shorter study showing improvements in erectile function but no change in depression and parkinsonisms after ED treatment (74).
In comparison, 37% of men who had received external radiotherapy as their primary therapy reported the ability to attain functional erections suitable for intercourse, along with 43% of men who had received brachytherapy as primary treatment. Pretreatment sexual health-related quality of life score, age, serum prostate-specific antigen (PSA) level, race or ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. 
Sexual dysfunction and ED become more common as men age. The percentage of complete ED increases from 5% to 15% as age increases from 40 to 70 years. But this does not mean growing older is the end of your sex life. ED can be treated at any age. Also, ED may be more common in Hispanic men and in those with a history of diabetes, obesity, smoking, and hypertension. Research shows that African-American men sought medical care for ED twice the rate of other racial groups.