A system for inserting a pellet of alprostadil into the urethra is marketed as MUSE. The system uses a pre-filled applicator to deliver the pellet about an inch deep into the urethra at the tip of the penis. An erection will begin within 8 to 10 minutes and may last 30 to 60 minutes. The most common side effects of the preparation are aching in the penis, testicles, and area between the penis and rectum; warmth or burning sensation in the urethra; redness of the penis due to increased blood flow; and minor urethral bleeding or spotting.
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
What to do: Close your eyes and relax. If you're overly nervous, you may have triggered your sympathetic nervous system, the so-called "fight or flight" reaction your body has in intense situations. This can prevent you from having an erection for between five and 15 minutes. So go back to the foreplay stage. Kiss passionately. Caress. Perform oral sex. Don't rush things. Let your instinct take over. Remember; she's a person, just like you.
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.
For the patient whose history suggests organic impotence, further history, physical and laboratory data will help identify the cause. The classification listed in Table 187.2 is based on the pathophysiologic scheme presented above, and includes mechanical problems that can interfere with erection. Vascular disease is the most common cause of impotence. In advanced cases, Lehriche's syndrome of aortoiliac occlusion will be suggested by bilateral thigh or calf claudication, loss of muscle mass in the buttocks and legs, and impotence. However, the majority of patients with vascular impotence have less severe vascular disease and many will have occlusive disease of the hypogastric-cavernous bed only. Even among patients without claudication, vascular disease is still a likely cause of impotence, especially if risk factors for atherosclerosis are present. Nonatherosclerotic disease is a consideration in the patient with a history of trauma or radiation to the pelvis, both of which cause fibrosis of vessels.
This point is important – the anticipatory anxiety. Sports men and women regularly use “mental rehearsal” to help them prepare for a match. They imagine the shots, the game and perform according to plan when the event arises. Research has show that musicians mentally practicing their instrument in their mind, use the same brain processes as when playing for real.
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.
The history can be useful in distinguishing organic from psychogenic impotence (Table 187.1). The patient with organic impotence describes problems with erection that progress over months to years. At first, the patient will have partial erections or seemingly firm erections that become flaccid during intercourse. With time, total erectile failure ensues. Organic impotence is constant and nonselective, meaning it is not better or worse with any specific partner or any type of stimulation.
The motivation and expectations of the patient and his partner and education of both are critical in determining which therapy is chosen and in optimizing its outcome. If single therapy is ineffective, combining two or more forms of therapy may be useful. Penile prostheses should be placed only after patients have been carefully screened and informed. Vascular surgery should be undertaken only in the setting of clinical investigation and extensive clinical experience. With any form of therapy for erectile dysfunction, long-term followup by health professionals is required to assist the patient and his partner with adjustment to the therapeutic intervention. This is particularly true for intracavernosal injection and vacuum constriction therapies. Followup should include continued patient education and support in therapy, careful determination of reasons for cessation of therapy if this occurs, and provision of other options if earlier therapies are unsuccessful.
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.
#2 Physically exhausted. If you’ve been cranking it at the gym, haven’t been sleeping well, or you’ve been working your ass off at your job, getting tangled up with your lover for even more physically demanding activities may not sound ideal. Physical exhaustion has a direct effect on your ability to get aroused. The only fix for this one is to get some rest.
Alprostadil self-injection. With this method, you use a fine needle to inject alprostadil (Caverject Impulse, Edex) into the base or side of your penis. In some cases, medications generally used for other conditions are used for penile injections on their own or in combination. Examples include papaverine, alprostadil and phentolamine. Often these combination medications are known as bimix (if two medications are included) or trimix (if three are included).
A common and important cause of ED is vasculogenic. Many men with ED have comorbid conditions such as hyperlipidemia, hypercholesterolemia, tobacco abuse, diabetes mellitus, or coronary artery disease (CAD).  The Princeton III Consensus recommends screening men who present with ED for cardiovascular risk factors; ED may be the earliest presentation of atherosclerosis and vascular disease. 
Let’s admit that not “talking about anything that could possibly be uncomfortable” is a sure-fire recipe for total disaster. Maybe you’re exaggerating, but if he can’t deal with anything even slightly difficult, then that is a bigger problem than pillow talk. Think about how exactly it would affect everything else in your relationship. He can’t choose not to deal. When good things are happening, it’s a shame he can’t say "I love you0". But when hard things happen, he can’t just say: "Um, pass."
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.