Some men should not take PDE5 inhibitors. They can cause hypotension (abnormally low blood pressure that can lead to fainting and even shock) when given to patients who are taking nitrates (medications taken for heart disease). Therefore, patients taking nitrates daily should not take any of the PDE5 inhibitors. Nitrates relieve angina (chest pain due to insufficient blood supply to the heart muscle because of narrowing of the coronary arteries); these include nitroglycerine tablets, patches, ointments, sprays, and pastes, as well as isosorbide dinitrate and isosorbide mononitrate. Other nitrates such as amyl nitrate and butyl nitrate also are in some recreational drugs called "poppers."
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
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."
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.
The general medical history is important in identifying specific risk factors that may account for or contribute to the patient's erectile dysfunction. These include vascular risk factors such as hypertension, diabetes, smoking, coronary artery disease, peripheral vascular disorders, pelvic trauma or surgery, and blood lipid abnormalities. Decreased sexual desire or history suggesting a hypogonadal state could indicate a primary endocrine disorder. Neurologic causes may include a history of diabetes mellitus or alcoholism with associated peripheral neuropathy. Neurologic disorders such as multiple sclerosis, spinal injury, or cerebrovascular accidents are often obvious or well defined prior to presentation. It is essential to obtain a detailed medication and illicit drug history since an estimated 25 percent of cases of erectile dysfunction may be attributable to medications for other conditions. Past medical history can reveal important causes of erectile dysfunction, including radical pelvic surgery, radiation therapy, Peyronie's disease, penile or pelvic trauma, prostatitis, priapism, or voiding dysfunction. Information regarding prior evaluation or treatment for "impotence" should be obtained. A detailed sexual history, including current sexual techniques, is important in the general history obtained. It is also important to determine if there have been previous psychiatric illnesses such as depression or neuroses.
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?
The most common inflatable prosthesis is the three-piece penile prosthesis. It is composed of paired cylinders, which doctors surgically insert inside the penis. Patients can expand the cylinders using pressurized fluid (see figure 3). Tubes connect the cylinders to a fluid reservoir and pump, which doctors also surgically implant. The reservoir is usually in the pelvis. A doctor places the pump in the scrotum. By pressing on the pump, sterile fluid transfers from the reservoir into the cylinders in the penis. An erection is produced primarily by expansion of the width of the penis, however, one model can increase in length a small amount also. Lock-out valves in the tubing prevent the fluid from leaving the cylinder until a release valve is pressed. By pressing the relief valve and gently squeezing the penis, the fluid within the cylinders transfers back into the reservoir.
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.
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.
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
Concerns that use of pornography can cause erectile dysfunction have not been substantiated in epidemiological studies according to a 2015 literature review. However, another review and case studies article maintains that use of pornography does indeed cause erectile dysfunction, and critiques the previously described literature review.
The main medical causes of erectile dysfunction are based around poor blood flow (due to furring of the arteries thanks to raised cholesterol or high blood pressure), poor nerve supply caused by diabetes-related nerve damage, or low testosterone as a result of obesity, old age or failing gonads. We doctors get just as concerned with men who have variable erections as well as those that can't get an erection at all. Failing to get an erection occasionally is pretty normal as you get older. But if you have unreliable erections for a prolonged period of time – more than six months – this could suggest an early sign of physical problems such as cardiovascular disease or diabetes which could develop further so get yourself checked out.
Sildenafil (Viagra) was the first oral phosphodiesterase type 5 (PDE5) inhibitor approved by the FDA in the United States for the treatment of erectile dysfunction (it is not approved for women). Sildenafil inhibits PDE5, which is an enzyme that destroys cGMP. By inhibiting the destruction of cGMP by PDE5, sildenafil allows cGMP to accumulate. The cGMP in turn prolongs relaxation of the smooth muscle of the corpora cavernosa. Relaxation of the corpora cavernosa smooth muscle allows blood to flow into the penis resulting in increased engorgement of the penis. In short, sildenafil increases blood flow into the penis and decreases blood flow out of the penis.
Endocrine problems, though uncommon, should be considered in patients presenting with impotence. As a rule, impotence due to hypogonadism will be partial and accompanied by decreased libido. Hypothalmic–pituitary problems, which include tumors, are the most common endocrine disorders causing impotence, followed by primary gonadal failure from one of many causes. Poorly controlled diabetes with polyuria and polydypsia is an important reversible cause of impotence, as is hyperthyroidism. Certain drugs, alcohol included, can lead to impotence as a result of endocrine disturbances.
Both ED and low testosterone (hypogonadism) increase with age. The incidence of the latter is 40% in men aged 45 years and older.  Testosterone is known to be important in mood, cognition, vitality, bone health, and muscle and fat composition. It also plays a key role in sexual dysfunction (eg, low libido, poor erection quality, ejaculatory or orgasmic dysfunction, reduced spontaneous erections, or reduced sexual activity). 
Erectile dysfunction (ED) is commonly called impotence. It’s a condition in which a man can’t achieve or maintain an erection during sexual performance. Symptoms may also include reduced sexual desire or libido. Your doctor is likely to diagnose you with ED if the condition lasts for more than a few weeks or months. ED affects as many as 30 million men in the United States.