The recommended starting dose of tadalafil for use as needed for most patients is 10 mg taken orally approximately one hour before sexual activity. A doctor may adjust the dose higher to 20 mg or lower to 5 mg depending on efficacy and side effects. Doctors recommended that patients take tadalafil no more frequently than once per day. Some patients can take tadalafil less frequently since the improvement in erectile function may last 36 hours. Patients may take tadalafil with or without food. Tadalafil is currently the only PDE5 inhibitor that is FDA-approved for daily use for erectile dysfunction and is available in 2.5 mg or 5 mg dosages for daily use.
Surgery for erectile dysfunction is usually considered only after all other options have failed. The two surgical options include the insertion of a semi-rigid rod or the implantation of a three-piece inflatable prosthesis. Penile prosthesis implantation has low infection, complication, and malfunction rates. However, since placement of an implant requires permanent injury to the erectile tissue of the penis, implant treatment is considered irreversible.
Obesity. Obesity itself is not a risk factor for ED — but there is a connection. “The bigger concern is that obesity can lead to type 2 diabetes or vascular diseases, which are risk factors for ED,” says Montague. Morbid obesity, a term used to classify individuals who are significantly overweight, can cause hormonal changes that are triggered by excess body fat. In addition, obesity can put physical limitations on sexual intercourse.
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.
The penis contains three cylinders, the two corpora cavernosa, which are on the top of the penis (see figure 1 below). These two cylinders are involved in erections. The third cylinder contains the urethra, the tube that the urine and ejaculate passes through, runs along the underside of the penis. The corpus spongiosum surrounds the urethra. Spongy tissue that has muscles, fibrous tissues, veins, and arteries within it makes up the corpora cavernosa. The inside of the corpora cavernosa is like a sponge, with potential spaces that can fill with blood and distend (known as sinusoids). A layer of tissue that is like Saran Wrap, called the tunica albuginea, surrounds the corpora. Veins located just under the tunica albuginea drain blood out of the penis.
The physical examination can reveal clues for physical causes of erectile dysfunction. A doctor will perform an assessment of BMI and waist circumference to evaluate for abdominal obesity. A genital examination is part of the evaluation of erectile dysfunction. The examination will focus on the penis and testes. The doctor will ask you about penile curvature and will examine the penis to see if there are any plaques (hard areas) palpable. The doctor will examine the testes to make sure they are in the proper location in the scrotum and are normal in size. Small testicles, lack of facial hair, and enlarged breasts (gynecomastia) can point to hormonal problems such as hypogonadism with low testosterone levels. A health care provider may check pulses in your groin and feet to determine if there is a suggestion of hardening of the arteries that could also affect the arteries to the penis.
To give you some evidence of the link between anxiety, stress, and ED consider the results of a study published in a 2015 edition of Comprehensive Psychiatry. In a study of case records for 64 men with erectile dysfunction or premature ejaculation, there was a significant link between ED and anxiety disorders or depression. Of the 64 participants, 8 had comorbid depressive disorders and 15 had anxiety disorders. In the majority of patients, these disorders predated the onset of sexual dysfunction which suggests that the disorders may have been a contributing factor.
Erectile dysfunction (ED) generally affects men older than 65, but younger men can get it too. If it happens at a younger age, ED may be a warning sign of another health issue. If you have no obvious risk factors and no other health problems, like diabetes, your doctor will run laboratory tests and may order heart tests. The same process that affects the arteries in the penis affects the ones in your heart, too. If something is wrong and it is not diagnosed and treated, you have a fairly high risk over the next four to five years of having some type of cardiac event.
The physical exam should focus on femoral and peripheral pulses, femoral bruits (vascular abnormalities), visual field defects (prolactinoma or pituitary mass), breast exam (hyperprolactinemia), penile strictures (Peyronie’s disease), testicle atrophy (testosterone deficiency), and asymmetry or masses (hypogonadism). A rectal exam allows for assessment of both the prostate and sphincter tone, abnormalities that are associated with autonomic dysfunction. Sacral and perineal neurological exam will help in assessing autonomic function.
In rare cases, the drug Viagra ® can cause blue-green shading to vision that lasts for a short time. In rare cases, the drug Cialis® can cause or increase back pain or aching muscles in the back. In most cases, the side effects are linked to PDE5 inhibitor effects on other tissues in the body, meaning they are working to increase blood flow to your penis and at the same time impacting other vascular tissues in your body. These are not ‘allergic reactions'.
At the same time, people with diabetes are susceptible to a type of blood vessel damage known as endothelial dysfunction. A recent study found that men with ED are at a greater risk of heart disease, which is also associated with endothelial dysfunction. If blood vessels aren't in good working order, the penis may not get enough blood for an erection.
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.
The vascular processes that produce an erection are controlled by the nervous system and certain prescription medications may have the side effect of interfering with necessary nerve signals. Among the possible culprits are a variety of stimulants, sedatives, diuretics, antihistamines, and drugs to treat high blood pressure, cancer, or depression. But never stop a medication unless your doctor tells you to. In addition, alcohol, tobacco, and illegal drugs, such as marijuana, may contribute to the dysfunction.
Luckily, awareness of ED as a significant and common complication of diabetes has increased in recent years, mainly because of increasing knowledge of male sexual function and the rapidly expanding armamentarium of novel treatments being developed for impotence. Studies of ED suggest that its prevalence in men with diabetes ranges from 35–75% versus 26% in general population. The onset of ED also occurs 10–15 years earlier in men with diabetes than it does in sex-matched counterparts without diabetes.