In prescribing sildenafil, a doctor considers the age, general health status, and other medication(s) the patient is taking. The usual starting dose for most men is 50 mg, however, the doctor may increase or decrease the dose depending on side effects and effectiveness. The maximum recommended dose is 100 mg every 24 hours. However, many men will need 100 mg of sildenafil for optimal effectiveness, and some doctors are recommending 100 mg as the starting dose.

ICI Alprostadil may be used as a mixture with two other drugs to treat ED. This combination therapy called "bimix or trimix" is stronger than alprostadil alone and has become standard treatment for ED. Only the Alprostadil ingredient is FDA approved for ED. The amount of each drug used can be changed based on the severity of your ED, by an experienced health professional. You will be trained by your health professional on how to inject, how much to inject and how to safely raise the drug's dosage if necessary.


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.
Chlamydia and erectile dysfunction: What's the link? Some people who have chlamydia also experience erectile dysfunction (ED), which involves problems getting or maintaining an erection. Chlamydia can infect the prostate gland, leading to prostatitis, pain, and ED. In this article, learn more about the link between this common infection and ED, and treatments for both. Read now
Not enough info for you? No problem. Nerd out on all the causes of erectile dysfunction with research from the most trusted sources on the interwebs. If you have any questions or you think we missed something important, leave a comment or book a consultation with one of these trained professionals and we’ll get you on the way to a healthier manhood.
The primary complication of the surgical implantation is postoperative infection, which occurs in about 8% of cases involving diabetes. This infection can be difficult to treat and may require the removal of the device, although this occurs <3% of the time. The infection can also cause penile erosion, reduced penile sensation, and auto-inflation. Glycemic control should be optimized several weeks before surgery. Once a patient has surgery, none of the oral agents or vacuum devices will work because of the destroyed penile architecture.
Alcohol is a depressant, not an aphrodisiac or a libido enhancer. Excessive consumption can interfere with the ability to achieve an erection at any age, and even occasional drinking can make erectile dysfunction worse in older men. Feloney advises using alcohol in moderation: "In small amounts, alcohol can relieve anxiety and may help with erectile dysfunction, but if you drink too much, it can cause erectile dysfunction or make the problem worse."
Alcohol abuse is the leading cause of impotence and other disturbances in sexual dysfunction.[3] Episodic erectile failure in alcoholic men is fairly routine, found to be significantly higher in men consuming more than three standard units of alcohol (12 g ethanol) daily and in subjects smoking more than 10 cigarettes/day.[4] Van Thiel and Lester[5] reported that 61% of patients dependent on alcohol reported sexual dysfunction, the most common being erectile dysfunction followed by reduced sexual desire. Erectile dysfunction and reduced sexual desire were frequently seen to be coexisting.[6–9] Vijayasenan,[10] found that of 97 male inpatients admitted for the treatment of alcoholism, 71% suffered from sexual dysfunction for a period of more than 12 months prior to admission to a hospital. The disturbances noted were diminished sexual desire (58%), ejaculatory incompetence (22%), erectile impotence (16%) and premature ejaculation (4%). Virtually all aspects of the human sexual response are affected by alcohol especially sexual desire and erection.[11]

CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is sage, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.

We can partially speak to this issue by looking at data from the first wave of the National Survey of Sexual Health and Behavior (NSSHB), a nationally representative US sex survey conducted in 2009 with thousands of Americans aged 14-94 [3]. As part of this study, male participants were asked whether they’d experienced any erectile difficulties the last time they had sex via a single item with five response options, ranging from “not difficult” to “very difficult.” Obviously, this is a quite different question compared to the other studies because it only focused on a single event (the most recent one in memory) and it was more complex than a simple yes/no answer. The researchers also divided men into slightly different age groups.
Erectile dysfunction related to medical/physical causes is often treatable but less commonly curable. In some cases of medication-induced erectile dysfunction, changes in medication may improve erections. Similarly, in men with a history of arterial trauma, surgical intervention can restore erectile dysfunction. In most cases of ED associated with a medical condition, treatment allows one to have an erection "on demand" or with the aid of medications/device (but not spontaneous).
The recommended starting dose of vardenafil is 10 mg taken orally approximately one hour before sexual activity. A doctor may adjust the dose higher or lower depending on efficacy and side effects. The maximum recommended dose is 20 mg, and the maximum recommended dosing frequency is no more than once per day. Patients can take vardenafil with or without food. As with sildenafil, for vardenafil to be effective, sexual stimulation must occur.

Cardiovascular diseases: The most common cause of cardiovascular diseases in the United States is atherosclerosis, the narrowing and hardening of arteries that reduces blood flow. Atherosclerosis (a type of vascular disease) typically affects arteries throughout the body; hypertension, high blood cholesterol levels, cigarette smoking, and diabetes mellitus aggravate atherosclerosis. Hardening of the arteries to the penis and pelvic organs, atherosclerosis, causes insufficient blood flow into the penis. There is a close correlation between the severity of atherosclerosis in the coronary arteries and erectile dysfunction. For example, men with more severe coronary artery atherosclerosis (hardening of the arteries in the heart) also tend to have more erectile dysfunction than men with mild or no coronary artery atherosclerosis. Some doctors suggest that men with new onset erectile dysfunction undergo evaluation for silent coronary artery diseases (advanced coronary artery atherosclerosis that has not yet caused angina or heart attacks).
Injury to the penis may cause the scar tissue to develop. Sex, sports, or an accident might cause the injury. However, most patients don’t remember any painful injury. There are risk factors that increase the chances that an injury may cause scar tissue. They are genetics, connective tissue disorders, and age. The risk of Peyronie’s increases with age.
Although few studies specifically evaluated the clinical characteristics of ED in younger men, this problem is increasingly frequent. Healthcare professionals both inside and outside of Sexual Medicine are likely to deal with young men complaining for ED and it is important that basic knowledge on this topic is available. In fact, young men reporting ED risk being dismissed without any specific medical assessment, including medical history or physical exam, owing to the assumption that ED in younger is a self-limiting condition, without any clinical consequence. However, evidence shows that, similar to middle-aged or older men, ED can be the consequence of the combination of organic, psychological and relational factors and all these components must be assessed for a correct clinical management. In particular, ED in younger, even more than in older men, can be considered a harbinger of CVD and it offers the unique opportunity to unearth the presence of CV risk factors, thus allowing effective and high quality preventive interventions.
Pornography addiction or dependence is a potential cause for ED that many men fail to consider. If you spend a great deal of time watching and masturbating to pornography, it could cause you to develop unrealistic expectations about sex or about your sexual partners. When this happens, your brain becomes “trained” to not only expect but, in a way, to need that kind of experience in order to achieve arousal and climax. Researchers have actually studied this effect and have given the condition its own name – pornography-induced erectile dysfunction (PIED).
Once evaluated, there are a number of treatments for erectile dysfunction, varying from oral therapies that can be taken on demand (for example, sildenafil [Viagra, Revatio], vardenafil [Levitra, Staxyn], avanafil [Stendra], and tadalafil [Cialis, Adcirca]) or once daily (tadalafil), intraurethral therapies (alprostadil [Muse]), injection therapies (alprostadil, combination therapies), the vacuum device, and penile prostheses. Less commonly, arterial revascularization procedures can be performed. It is important to discuss the indications and risks of each of these therapies to determine which is best for you.
As recently as two decades ago, doctors tended to blame erectile dysfunction on psychological problems or, with older men, on the normal aging process. Today, the pendulum of medical opinion has swung away from both notions. While arousal takes longer as a man ages, chronic erectile dysfunction warrants medical attention. Moreover, the difficulty is often not psychological in origin. Today, urologists believe that physical factors underlie the majority of cases of persistent erectile dysfunction in men over age 50.
Is your erectile dysfunction due to psychological (stress, relationship problems, etc.) or physical factors? Your doctor may ask if you note erections at night or in the early morning. Men have involuntary erections in the early morning and during REM sleep (a stage in the sleep cycle with rapid eye movements). Men with psychogenic erectile dysfunction (erectile dysfunction due to psychological factors such as stress and anxiety rather than physical factors) usually maintain these involuntary erections. Men with physical causes of erectile dysfunction (for example, atherosclerosis, smoking, and diabetes) usually do not have these involuntary erections. Men with psychogenic erectile dysfunction may relate the onset of problems to a "stressor," such as failed relationship. Your doctor may suggest a test to determine if you have erections during sleep, which may suggest that there may be a psychological cause of the erectile dysfunction.
Sexuality and erection are controlled by multiple areas of the human brain including the hypothalamus, the limbic system, and the cerebral cortex. Stimulatory or inhibitory messages are relayed to the spinal erection centers to facilitate or inhibit erection (5). Two mechanisms have been proposed to explain the inhibition of erection in psychogenic dysfunction: direct inhibition of the spinal erection center by the brain as an exaggeration of the normal suprasacral inhibition and excessive sympathetic outflow or elevated peripheral catecholamine levels, which may increase penile smooth muscle tone and prevent the relaxation necessary for erection (8). Animal studies demonstrate that the stimulation of sympathetic nerves or systemic infusion of epinephrine causes detumescence of the erect penis (6,7). Clinically, higher levels of serum norepinephrine have been reported in patients with psychogenic ED than in normal controls or patients with vasculogenic ED (9).
When we say it’s a barometer of men’s health, it’s a signal. It’s an indicator that things may be right or not. And so when a man develops an erectile problem– and we’re talking about something that is occurring over time. It’s not something that just occurred overnight. When it occurs overnight, it’s more often than not a psychogenic, an anxiety reaction.

Erectile dysfunction (ED), also known as impotence, is the inability to achieve or sustain a hard enough erection for satisfactory completion of sexual activity. Erectile dysfunction is different from other health conditions that interfere with male sexual function, such as lack of sexual desire (decreased libido) and problems with ejaculation release of the fluid from the penis (ejaculatory dysfunction) and orgasm/climax (orgasmic dysfunction), and penile curvature (Peyronie's disease), although these problems may also be present. ED affects about 50% of men age 40 and over. This article focuses on the evaluation and treatment of erectile dysfunction.

Natural treatments: Although natural remedies are increasingly available for sale over the counter, there is little scientific evidence to support their claims of improving ED. These remedies may produce adverse side effects or react negatively with other medications a man is taking. Before trying any over-the-counter treatments, it is essential to consult a doctor.


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.


Drugs.com provides accurate and independent information on more than 24,000 prescription drugs, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. Data sources include IBM Watson Micromedex (updated 9 Jan 2019), Cerner Multum™ (updated 14 Jan 2019), Wolters Kluwer™ (updated 7 Jan 2019) and others. Refer to our editorial policy for content sources and attributions.
These are not currently approved by the FDA for ED management, but they may be offered through research studies (clinical trials). Patients who are interested should discuss the risks and benefits (informed consent) of each, as well as costs before starting any clinical trials. Most therapies not approved by the FDA are not covered by government or private insurance benefits.
Erectile dysfunction is often an early warning sign of more serious problems like hypertension, diabetes, obesity, and cholesterol. That’s why we call ED your body’s “check engine light”. The blood vessels in the penis are smaller than the rest of the body, especially the blood vessels that lead to the heart and brain. So ED is usually the first sign of high cholesterol or high blood pressure before a blockage causes more serious problems, like a heart attack or stroke.
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.
×