PDE 5 inhibitors are broken down primarily by enzyme, cytochrome P450enzyme CYP3A4. Medications that decrease or increase the activity of CYP3A4 may affect levels and effectiveness of PDE 5 inhibitors. Such drugs include medications for the treatment of HIV (protease inhibitors) and the antifungal medications ketoconazole and itraconazole. Thus caution is recommended.
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.
This process comprises a variety of physical aspects with important psychological and behavioral overtones. In analyzing the material presented and discussed at this conference, this consensus statement addresses issues of male erectile dysfunction, as implied by the term "impotence." However, it should be recognized that desire, orgasmic capability, and ejaculatory capacity may be intact even in the presence of erectile dysfunction or may be deficient to some extent and contribute to the sense of inadequate sexual function.
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".

Injection of vasodilator substances into the corpora of the penis has provided a new therapeutic technique for a variety of causes of erectile dysfunction. The most effective and well-studied agents are papaverine, phentolamine, and prostaglandin E[sub 1]. These have been used either singly or in combination. Use of these agents occasionally causes priapism (inappropriately persistent erections). This appears to have been seen most commonly with papaverine. Priapism is treated with adrenergic agents, which can cause life-threatening hypertension in patients receiving monoamine oxidase inhibitors. Use of the penile vasodilators also can be problematic in patients who cannot tolerate transient hypotension, those with severe psychiatric disease, those with poor manual dexterity, those with poor vision, and those receiving anticoagulant therapy. Liver function tests should be obtained in those being treated with papaverine alone. Prostaglandin E[sub 1] can be used together with papaverine and phentolamine to decrease the incidence of side effects such as pain, penile corporal fibrosis, fibrotic nodules, hypotension, and priapism. Further study of the efficacy of multitherapy versus monotherapy and of the relative complications and safety of each approach is indicated. Although these agents have not received FDA approval for this indication, they are in widespread clinical use. Patients treated with these agents should give full informed consent. There is a high rate of patient dropout, often early in the treatment. Whether this is related to side effects, lack of spontaneity in sexual relations, or general loss of interest is unclear. Patient education and followup support might improve compliance and lessen the dropout rate. However, the reasons for the high dropout rate need to be determined and quantified.

Think of erectile dysfunction as your body’s “check engine light.” The blood vessels in the penis are smaller than other parts of the body, so underlying conditions like blocked arteries, heart disease, or high blood pressure usually show up as ED before something more serious like a heart attack or stroke. ED is your body’s way of saying, “Something is wrong.” And the list of things that cause erectile dysfunction can include:
Remember those cultural messages we discussed earlier, about how men are wild sex aliens from the planet Weenus? Well, men are raised hearing those messages, too, and they can end up screwing with their sexual self-image —for instance, they can lead men to obsess over their own virility, and panic about impressing a new partner, until they've thought their boner into a corner and can't get an erection. Performance anxiety is one of the most common culprits behind lost erections, especially among younger, less experienced men.
Alteration of NO levels is the focus of several approaches to the treatment of ED. Inhibitors of phosphodiesterase, which primarily hydrolyze cGMP type 5, provided the basis for the development of the PDE5 inhibitors. Chen et al administered oral L-arginine and reported subjective improvement in 50 men with ED. [14] These supplements are readily available commercially. Reported adverse effects include nausea, diarrhea, headache, flushing, numbness, and hypotension.
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.
The causes of erectile dysfunction include aging, high blood pressure, diabetes mellitus, cigarette smoking, atherosclerosis (hardening of the arteries), depression, nerve or spinal cord damage, medication side effects, alcoholism or other substance (drug) abuse, pelvic surgery including radical prostatectomy, pelvic radiation, penile/perineal/pelvic trauma such as pelvic fracture, Peyronie's disease (a disorder that causes curvature of the penis and sometimes painful erections), and low testosterone levels.
But if the blood flow is weak here, it is highly likely that it is also weak in arteries supplying the heart, raising the risk of a heart attack. In fact, some studies suggest that women with heart disease may also suffer sexual dysfunction: the clitoris, like the penis, is a vascular organ, and also relies on healthy blood flow for successful orgasms.
#4 You’re just plain turned off. It happens. Whether it’s the weight your partner has put on, the realization that you’re having period sex, or you’re just not getting what you need in the bedroom, at some point in your life, you’re going to be turned off enough to lose *or be unable to attain* your hard-on. [Read: Not attracted to your girlfriend anymore? The why and the fixes]
Remember those cultural messages we discussed earlier, about how men are wild sex aliens from the planet Weenus? Well, men are raised hearing those messages, too, and they can end up screwing with their sexual self-image —for instance, they can lead men to obsess over their own virility, and panic about impressing a new partner, until they've thought their boner into a corner and can't get an erection. Performance anxiety is one of the most common culprits behind lost erections, especially among younger, less experienced men.

Did you know that erectile dysfunction precedes coronary artery disease in almost 70 percent of cases.2 The arteries in the penis are smaller than those that cause heart disease symptoms, which means they are likely to be affected by blockages sooner. When the arteries in the penis are blocked, keeping an erection will be difficult regardless of your level of arousal.

This penile tumescence monitor is placed at the base and near the corona of the penis. It is connected to a monitor that records a continuous graph depicting the force and duration of erections that occur during sleep. The monitor is strapped to the leg. The nocturnal penile tumescence test is conducted on several nights to obtain an accurate indication of erections that normally occur during the alpha phase of sleep.


Other medical therapies under evaluation include ROCK inhibitors and soluble guanyl cyclase activators. Melanocortin receptor agonists are a new set of medications being developed in the field of erectile dysfunction. Their action is on the nervous system rather than the vascular system. PT-141 is a nasal preparation that appears to be effective alone or in combination with PDE5 inhibitors. The main side effects include flushing and nausea. These drugs are currently not approved for commercial use.
Fact is, almost all men experience erection problems from time to time. Sometimes it's a temporary condition that will go away with just power of mind or little treatment. But unfortunately in many cases it may be an ongoing problem. Whatever it is, if you don't want to eventually destroy your self esteem and harm relationship with your lover, immediate treatment is required.

Malleable implants usually consist of paired rods, inserted surgically into each of the corpora cavernosa. The rods are stiff, and to have an erection, one bends them up and then when finished with intercourse one bends them down. They do not change in length or width. The malleable implants are the least mechanical and thus have the lowest risk of malfunction. However, also have the least "normal appearance."


A rigid or nearly rigid erectile response to intracavernous injection of pharmacologic test doses of a vasodilating agent (see below) indicates adequate arterial and veno-occlusive function. This suggests that the patient may be a suitable candidate for a trial of penile injection therapy. Genital stimulation may be of use in increasing the erectile response in this setting. This diagnostic technique also may be used to differentiate a vascular from a primarily neuropathic or psychogenic etiology. Patients who have an inadequate response to intracavernous pharmacologic injection may be candidates for further vascular testing. It should be recognized, however, that failure to respond adequately may not indicate vascular insufficiency but can be caused by patient anxiety or discomfort. The number of patients who may benefit from more extensive vascular testing is small, but includes young men with a history of significant perineal or pelvic trauma, who may have anatomic arterial blockage (either alone or with neurologic deficit) to account for erectile dysfunction.
Finally, there are NO-releasing polymers that are capable of delivering NO in a pharmacologically useful way. Such compounds include compounds that release NO upon being metabolised and compounds that release NO spontaneously in aqueous solution. Initial animal studies suggest that cavernosal injections of NO polymers can significantly improve erectile function.48
Studies to further define vasculogenic disorders include pharmacologic duplex grey scale/color ultrasonography, pharmacologic dynamic infusion cavernosometry/ cavernosography, and pharmacologic pelvic/penile angiography. Cavernosometry, duplex ultrasonography, and angiography performed either alone or in conjunction with intracavernous pharmacologic injection of vasodilator agents rely on complete arterial and cavernosal smooth muscle relaxation to evaluate arterial and veno-occlusive function. The clinical effectiveness of these invasive studies is severely limited by several factors, including the lack of normative data, operator dependence, variable interpretation of results, and poor predictability of therapeutic outcomes of arterial and venous surgery. At the present time these studies might best be done in referral centers with specific expertise and interest in investigation of the vascular aspects of erectile dysfunction. Further clinical research is necessary to standardize methodology and interpretation, to obtain control data on normals (as stratified according to age), and to define what constitutes normality in order to assess the value of these tests in their diagnostic accuracy and in their ability to predict treatment outcome in men with erectile dysfunction.
Talk with your doctor before trying supplements for ED. They can contain 10 or more ingredients and may complicate other health conditions. Asian ginseng and ginkgo biloba (seen here) are popular, but there isn't a lot of good research on their effectiveness. Some men find that taking a DHEA supplement improves their ability to have an erection. Unfortunately, the long-term safety of DHEA supplements is unknown. Most doctors do not recommend using it.
×