In most healthy men, some of the drug will remain in the body for more than two days after a single dose of tadalafil. Metabolism (clearing of the drug from the body) of tadalafil can be slowed by liver disease, kidney disease, and concurrent use of certain medications (such as erythromycin, ketoconazole, and protease inhibitors). Slowed breakdown allows tadalafil to stay in the body longer and potentially increase the risk for side effects. Therefore, doctors have to lower the dose and frequency of tadalafil in the following examples:
Examination of the vascular system is particularly relevant to the evaluation of the impotent patient. Absence of pulses in the feet and presence of femoral bruits suggest atherosclerosis. However, normal femoral and pedal pulses do not exclude selective obstruction to penile blood flow. Direct palpation of the dorsal artery of the penis may be informative if pulsation is absent. The presence of a pulse, however, does not rule out vascular disease, particularly in a patient who is able to achieve normal erections at rest, but unable to maintain them during thrusting. At the same time that the penile pulses are palpated, the examiner should feel for plaques in the corpora cavernosa which would indicate Peyronie's disease.
Patients receiving penile prostheses should be instructed in the operation of the prosthesis before surgery and again in the postoperative period. The prosthesis usually is not activated until approximately 6 weeks after surgery, so as to allow the edema and pain to subside. The prosthesis is checked in the office before the patient begins to use it.
Most older men suffer not ED but erection dissatisfaction. Starting around age 50 (often earlier among smokers and/or diabetics), erections change. In some men, the process is gradual, in others, it happens more quickly. Either way, older men lose the ability to raise erections solely from sexual fantasies. Direct fondling of the penis becomes necessary. When erections appear, they rise more slowly and do not become as firm as they were during men’s thirties and forties. And minor distractions may cause wilting—the doorbell or an ambulance siren. These changes alarm many men, who jump to the conclusion that they must have ED. If you can still raise erection durings masturbation, you don’t. What you have is erection dissatisfaction.
The first line and by far the most common treatment today is with the prescription drug sildenafil citrate, sold under the brand name Viagra. An estimated 20 million prescriptions for the pill have been filled since it was approved by the FDA in March 1998. It is also the most effective treatment with a success rate of more than 60%. The drug boosts levels of a substance called cyclic GMP, which is responsible for widening the blood vessels of the penis. In clinical studies, Viagra produced headaches in 16% of men who took it, and other side effects included flushing, indigestion, and stuffy nose.
The FDA does not recommend alternative therapies to treat sexual dysfunction.[24] Many products are advertised as "herbal viagra" or "natural" sexual enhancement products, but no clinical trials or scientific studies support the effectiveness of these products for the treatment of erectile dysfunction, and synthetic chemical compounds similar to sildenafil have been found as adulterants in many of these products.[25][26][27][28][29] The United States Food and Drug Administration has warned consumers that any sexual enhancement product that claims to work as well as prescription products is likely to contain such a contaminant.[30]

Vijay Bhat, MD is a board certified internal medicine physician who is passionate about providing quality medical care that’s affordable for patients. He believes that integrating technology and medicine can make healthcare efficient and more accessible. Throughout his training Dr. Bhat was involved with global health initiatives, providing care to underprivileged communities locally and overseas. He’s also been a strong proponent of quality improvement in the medical field. Dr. Bhat graduated with a BS from the University of California Berkeley, and received his medical degree from Stony Brook University in New York. He completed his residency in Internal Medicine at Rutgers Robert Wood Johnson.
A number of herbs have been promoted for treating impotence. The most widely touted herbs for this purpose are Coryanthe yohimbe (available by prescription as yohimbine, with the trade name Yocon) and gingko (Gingko biloba), although neither has been conclusively shown to help the condition in controlled studies. In addition, gingko carries some risk of abnormal blood clotting and should be avoided by men taking blood thinners such as coumadin. Other herbs promoted for treating impotence include true unicorn root (Aletrius farinosa), saw palmetto (Serenoa repens), ginseng (Panax ginseng), and Siberian ginseng (Eleuthrococcus senticosus). Strychnos Nux vomica has been recommended, especially when impotence is caused by excessive alcohol, cigarettes, or dietary indiscretions, but it can be very toxic if taken improperly, so it should be used only under the strict supervision of a physician trained in its use.
On the horizon is gene therapy that would deliver genes that produce products or proteins that may not be functioning properly in the penile tissue of men with ED. Replacement of these proteins may result in improvement in erectile function. Experimental animal models have demonstrated improvement in erectile function with gene therapy. Human studies may also demonstrate success with this therapy. Gene therapy may take a long time for regulatory approval and public acceptance.
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.

Normal erectile function depends on the release of NO and endothelial-dependent vasodilation of the penile arteries. The ‘artery size’ hypothesis, first described by Dr Montorsi, offers an explanation why men are more likely to develop ED before a myocardial infacrtion. It is believed that atherosclerosis affects all vascular beds equally but smaller arteries are more likely to become occluded than larger arteries.31 32 The penile arteries are 1–2 mm while the coronary arteries are 3–4 mm. Thus, the same degree of endothelial dysfunction and atherosclerosis is more likely to occlude blood flow in the penile arteries compared with the coronary arteries. The penile arteries therefore serve as a sensitive indicator for subsequent CVD. This theory is supported by the fact that ED occurs approximately 3 years prior to cardiac symptoms in virtually all patients with chronic coronary syndrome whereas patients with acute coronary syndrome have a much lower prevalence of sexual dysfunction.32

Between 10 and 88% of patients diagnosed with cancer experience sexual problems following diagnosis and treatment. The prevalence varies according to the location and type of cancer, and the treatment modalities used. Sexuality may be affected by chemotherapy, alterations in body image due to weight change, hair loss or surgical disfigurement, hormonal changes, and cancer treatments that directly affect the pelvic region.
However, men are affected psychologically when it comes to achieving erections. For instance, if a man is with a woman for the first time, or even before he feels comfortable with her, he may suffer from performance anxiety. In such a situation, his mind and body are both saying yes, but then they become out of sync. The body is then saying yes, but the mind is filled with question. “Will I be able to perform?” “How long will I last?” “Am I big enough to satisfy her?” “Is she looking at that mole on my stomach?” All kinds of questions may be going through a man’s mind upon getting in bed, and these can be distracting, they can lead to self-doubt, and therefore, failure to achieve or maintain an erection.

So not only are erectile problems common, they're nothing for you or your special friend to be freaked out about. Check out the nine most common reasons that dudes sometimes can't get it up, and get ready to become the soothing voice of reason the next time the guy you're with has a hard time pitching his tent in your happy valley. Everything (and every penis) is gonna be fine!


While studies are limited, it has been shown that male sexual dysfunction can also negatively impact the sexual function of female partners. A study comparing the sexual function of women with partners with erectile dysfunction to those without showed that sexual arousal, lubrication, orgasm, satisfaction, pain and total score were significantly lower in those who had partners with erectile dysfunction. Later in that study, a large proportion of the men with erectile dysfunction underwent treatment. Following treatment, sexual arousal, lubrication, orgasm, satisfaction and pain were all significantly increased. It was concluded that female sexual function is impacted by male erection status, which may improve following treatment of male sexual dysfunction.
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.
Another common problem for men who have trouble in the bedroom is substance use or abuse. In some cases, a man suffering from erectile dysfunction may be diagnosed with depression and be prescribed selective serotonin reuptake inhibitors, or SSRIs. These medications may be able to assist in alleviating the symptoms of depression, but they can also lead to erectile dysfunction.
Picture the scene. You get home from the bar with your date. You both decided to leave a little early, after only two drinks, because the chemistry was really there and both of you wanted to cut to the chase and get intimate. To discover each other's bodies. To eat of the fruits of passion. In short, to have sex. You stick the key in the lock, swing the door open, and invite her into your beautiful place. OK, well it might not be exactly beautiful. It might be a bit of a mess, frankly. But you don't let that ruin the moment. You turn around and passionately kiss her. How the two of you make it to your bedroom with some clothing still on is anybody's guess. You jump on the bed and hurriedly strip. God — can't this go any faster, you wonder? 
There are hundreds of medications that have the side effect of ED and/or decreased libido. Examples of drugs implicated as a cause of ED include hydrochlorothiazides and beta-blocking agents. Medications used to treat depression, particularly the SSRIs such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, Prozac Weekly, Sarafem), fluvoxamine (Luvox, Luvox CR), paroxetine (Paxil, Paxil CR, Pexeva) and sertraline (Zoloft), may also contribute to ED.9 Bupropion (Wellbutrin) which has a predominant effect on blocking the reuptake of dopamine is an antidepressant with lower incidence of ED.10 The side effects of 5ARIs occurring in fewer than 5% of patients can include gynaecomastia, ED, loss of libido and ejaculatory dysfunction.11
The role of the endothelium in erectile function became clearer with the observation that the phosphodiesterase type 5 (PDE5) inhibitor, sildenafil, enhanced erectile function. Erection occurs with the release of nitric oxide (NO) from the vascular endothelial cells.17 The reduction in endothelial cell production of NO results in the negative impact on the smooth muscles in the corporal bodies and results in less relaxation of the smooth muscle cells with decrease in blood supply and resulting ED. A similar phenomenon is well known to impact the coronary arterial system resulting in CVD.
None of the ED drugs is safe to take with cardiac drugs called nitrates because it could cause a dangerous drop in blood pressure. Drugs that many men take for urinary symptoms, called alpha blockers, can also lower blood pressure, so take them at least four hours apart from ED drugs. Your doctor may start you on a smaller dose of the ED drug if you already take an alpha blocker, or may recommend the alpha blocker tamsulosin (Flomax), which affects blood pressure less.
All these treatments listed above do not provide immediate effect on your body. If you need an instant erection, you should take a look at the topical erection treatment. Targeted delivery has been recently identified as an emerging alternative to orally administered products mainly due to the current concerns of the side effects that may occur from taking prescription drugs. Topical erection treatment presents a preferable delivery method to get an erection that enhances the desired effect directly to the intended site of action while limiting the exposure of the rest of the body to the ingredients.
If surgical intervention is an acceptable option, the work-up then proceeds with a noctural penile tumescense (NPT) test, the single most valuable study to establish the diagnosis of organic impotence. The NPT test exploits the fact that males from birth to old age normally have erections during rapid eye movement (REM) sleep. Psychogenic impotence is associated with normal erections during sleep. In organic impotence there should be no evidence of erection or, if erections are present, they should be limited and poorly sustained.

But the main challenge to finding the best ED drug for you may turn out to be health insurance rules—not biochemistry. It's a common practice among insurers to limit the number of pills you can obtain per month. After you hit your limit, the out-of-pocket cost for a single pill can be as high as $20. "The main obstacle in my practice is the cost," Dr. Liou says. You'll need to work with your doctor to get the pill you need at a price you can afford.
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.
There are, as you listen to all of the advertisements, if your erection lasts for more than four hours, there are very, very unusual cases where that can happen. There are very rare cases of visual problems. There are even rarer cases of hearing problems. But with every medication, there always a potential downside. But the absolute contraindication is an unstable medical condition, an unstable cardiovascular condition, being on nitrates.
Among the phenomena in the ageing man are a decrease in erectile function and testosterone levels. Add to these, increased risk for CVD, muscle wasting, decrease in bone density and libido, with all of these factors having an interplay with testosterone metabolism.33 Androgens play a key role in maintaining erectile function through four main mechanisms. Androgen deprivation has been shown to result in impairment of NO synthase release, altered PDE5 expression and activity, impaired cavernosal nerve function, and contribution to veno-occlusive disease in the penis.34 The role of testosterone replacement therapy (TRT) as a potential to improve erectile function in the man with ED remains an issue for patient and physicians who are comfortable treating androgen deficiency which include primary care physicians and specialists. Androgens are known to have a significant impact on the function of the smooth musculature within the corpus spongiosum.35

Stress is another factor that can be a cause or effect of ED. If you're stressed at work, at home, and in your relationships, it's going to take a toll on your sexual function. Your mind is elsewhere, and relaxing when you finally make it between the sheets is a long shot. Now you’re stressed because you can’t get it up (talk about the ultimate catch-22), so you're stuck in this sad, frustrating cycle. “ED really affects the psyche of a guy, regardless of the etiology, Gittens says. “If you have a problem getting an erection one night, you’re probably going to be anxious and worried your partner might see you as less of a man the next time you try to get an erection.” There's a pill that will help with this, and it's not promoted on television with middle-aged men in sports cars. It's a damn chill pill.
A useful and simple way to distinguish between physiological and psychological impotence is to determine whether the patient ever has an erection. If never, the problem is likely to be physiological; if sometimes (however rarely), it could be physiological or psychological. The current diagnostic and statistical manual of mental diseases (DSM-IV) has included a listing for impotence.
Picture this: you have the girl of your dreams laid out before you. You’re kissing and things are getting hot and heavy. There’s just one problem: you can’t get hard. Your thoughts quickly turn from “this is amazing” to “this is a disaster,” and before you know it, the story of your floppy dick is making its way down your lover’s social circle. That is if she’s an insensitive gossip. Either way, not being able to get a boner when the time is right is beyond embarrassing.
Under normal circumstances, when a man is sexually stimulated, his brain sends a message down the spinal cord and into the nerves of the penis. The nerve endings in the penis release chemical messengers, called neurotransmitters, that signal the corpora cavernosa (the two spongy rods of tissue that span the length of the penis) to relax and fill with blood. As they expand, the corpora cavernosa close off other veins that would normally drain blood from the penis. As the penis becomes engorged with blood, it enlarges and stiffens, causing an erection. Problems with blood vessels, nerves, or tissues of the penis can interfere with an erection.
Defined as experiencing difficulty having an erection at least 50 percent of the time, about 30 million men in the U.S. suffer from erectile dysfunction (ED), according to the National Institutes of Health. So, if odds are pretty good you’ll experience a failure to launch at some point in your life, take solace in this finding from the University of Adelaide: You can reverse ED by focusing on lifestyle factors, not just popping a blue pill.
The pathogenesis of organic ED is related to dysfunction of the endothelium. Endothelial cells can become injured through a variety of mechanisms, most of which cause oxidative stress on the tissues. Many of these causes of oxidative stress are related to lifestyle issues which lead to hypertension, diabetes and dyslipidaemia (figure 1). Endothelial cell dysfunction results in reduction of endothelium-dependent vasorelaxation as well as increased adhesion of leukocytes to the endothelium. Endothelial cell injury then leads to a variety of sequelae, including ED, other types of vasoconstriction, atherosclerosis and thrombus formation.18
In some cases, ED can be a warning sign of more serious disease. One study suggests ED is a strong predictor of heart attack, stroke, and death from cardiovascular disease. The researchers say all men diagnosed with ED should be evaluated for cardiovascular disease. This does not mean every man with ED will develop heart disease, or that every man with heart disease has ED, but patients should be aware of the link.
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