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:
More recent estimates suggest that the number of U.S. men with erectile dysfunction may more likely be near 10-20 million. Inclusion of individuals with partial erectile dysfunction increases the estimate to about 30 million. The majority of these individuals will be older than 65 years of age. The prevalence of erectile dysfunction has been found to be associated with age. A prevalence of about 5 percent is observed at age 40, increasing to 15-25 percent at age 65 and older. One-third of older men receiving medical care at a Department of Veterans' Affairs ambulatory clinic admitted to problems with erectile function.
It is essential to discuss erectile dysfunction with your doctor, so any serious underlying causes can be excluded and treatment options can be discussed. Many men are embarrassed discussing this issue with their doctor, or even their partner. Open communication with your doctor, and in your relationship, is important for effectively managing this common problem.
A semi-firm penis if correctly handled can give a somewhat pleasant orgasm. I really don't think there is such a thing as an unpleasant orgasm though. I have have ED for two years. It has been than long since I had sex with my wife in her vagina. There has been plenty of oral sex for her. The ED drugs do not work with me. I take injectable Testosterone, and that does not make a big difference. About twice a month I am able to masturbate. Hey I am glad to know it still works. Next week I am going to see urologist number 2. The first one was a jerk and basically wrote me off because of my age. Now I have read about the Viberect device and the NEW pudendal artery (to the penis). There is hope, but in the mean time I will masturbate as often as I can.
The Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) study, designed to determine whether an individual man’s sexual outcomes after most common treatments for early-stage prostate cancer could be accurately predicted on the basis of baseline characteristics and treatment plans, found that 2 years after treatment, 177 (35%) of 511 men who underwent prostatectomy reported the ability to attain functional erections suitable for intercourse. 
How’s this for a win-win: The more sex you have, the less likely you are to suffer from erectile dysfunction, according to a 2008 study published in The American Journal of Medicine. Men aged 55-75 who reported having sex less than once per week had twice the incidence of erectile dysfunction (there were 79 cases of ED per 1,000) as men who have sex once a week (32 cases of ED per 1,000). But if you really want to up your odds, shoot for three times per week (only 16 cases of ED per 1,000). Can you really argue with science, or a perscription to have more sex?
Metabolism (breakdown) of vardenafil can be slowed by aging, liver disease, and concurrent use of certain medications (such as erythromycin [an antibiotic], ketoconazole [Nizoral, a medication for fungal/yeast infections], and protease inhibitors [medications used to treat AIDS]). Slowed breakdown allows vardenafil to accumulate in the body and potentially increase the risk for side effects. Therefore, in men over 65 years of age with liver disease, or who are also taking medication(s) that can slow the breakdown of vardenafil, the doctor will initiate vardenafil at low doses to avoid its accumulation. For example,
Phosphodiesterase inhibitors: This class of medications includes sildenafil, tadalafil, and vardenafil. They work by inhibiting an enzyme called phosphodiesterase type 5 (PDE-5), allowing more blood to enter the penis and helping to produce an erection. These medications are often taken before sex and will cause an erection only when the man is sexually stimulated.
Q. I started to suffer from erectile dysfunction? Why is this happening and what can I do to treat it? I am a healthy 52 year old. I have hypertension but i take pills to treat it and my levels are around 130/80. except that I am at great shape. In the last few months I feel that a problem in my sex life. I want to have sex but i can't due to erectile dysfunction. What can be the reason for this? and more important what can I do?
I always made sure to satisfy my woman first, from the start of our marriage. When I started having issues with ED a few years ago, I talked to her about it and asked for her to be understanding and also that I needed a lot of the things sexually that she had not really given me much of, regardless of how much pampering or pleasing I did for her. She agreed, but never really stepped it up despite me talking to her about it every few weeks trying to salvage my own interest in sex. I had chased her constantly for over 10 years, then after the psychological effects of ED took their toll and she never really followed through helping me, my sex drive just tanked. I stopped chasing her, then after a little while she slowly started wanting it enough to initiate. Even then, she still wants the same sex as before, without the things I want being a regular part of it. My sex drive is still very low, and I still make an effort, but I can tell that my interest in sex is just deteriorating every time I have an ED episode and feel my desires being neglected. Each time, it just makes me less interested in continuing to try "serve" her because she does not return the favor much. The idea of spending so much effort doing "other stuff" while my wants and desires are barely recognized makes sex sound as exciting as mowing the yard to me now days.
The link between chronic disease and ED is most striking for diabetes. Men who have diabetes are two to three times more likely to have erectile dysfunction than men who do not have diabetes. Among men with erectile dysfunction, those with diabetes may experience the problem as much as 10 to 15 years earlier than men without diabetes. Yet evidence shows that good blood sugar control can minimize this risk. Other conditions that may cause ED include cardiovascular disease, atherosclerosis (hardening of the arteries), kidney disease, and multiple sclerosis. These illnesses can impair blood flow or nerve impulses throughout the body.