In the Massachusetts Male Aging Study (MMAS) among a community-based survey of men aged 40-70 years, 52% of the men reported some degree of erectile difficulty. Complete ED, defined as the total inability to obtain or maintain suitable erections during sexual stimulation, as well as the absence of nocturnal erections (normal erections [four to six/night], which occur during sleep), occurred in 10% of the men in the study. Lesser degrees of mild and moderate ED occurred in 17% and 25% of participants.
Medications: Many common medicines produce erectile dysfunction as a side effect. Medicines that can cause erectile dysfunction include many used to treat high blood pressure, antihistamines, antidepressants, tranquilizers, and appetite suppressants. Examples of common medicines that can cause erectile dysfunction include propranolol (Inderal) or other beta-blockers, hydrochlorothiazide, digoxin (Lanoxin), amitriptyline (Elavil), famotidine (Pepcid), cimetidine (Tagamet), metoclopramide (Reglan), naproxen, indomethacin (Indocin), lithium (Eskalith, Lithobid), verapamil (Calan, Verelan, Isoptin), phenytoin (Dilantin), gemfibrozil (Lopid), amphetamine/dextroamphetamine (Adderall), and phentermine. Prostate cancer medications that lower testosterone levels such as leuprolide (Lupron) may affect erectile function. Some chemotherapies such as cyclophosphamide (Cytoxan) may affect erectile function.
Men who do not respond or tolerate oral medications are best treated with an internal penile pump (IPP) commonly known as an inflatable implant. The Internal Penile Pump is an inflatable, water-filled device. During the course of a 45-minute outpatient procedure, the pump is inserted through a one-inch opening in the scrotal sac. By squeezing the pump, (which is contained completely within the scrotum), for approximately a minute, fluid is pumped into the penis, resulting in a long lasting erection. To return the penis to its flaccid state, simply press and hold down the pump. Once inserted, there is no maintenance required for the pump, which can remain in place for a lifetime. Couples are once again able to have spontaneous sex. Normal sensation including orgasm and ejaculation are not affected.
Besides PDE5 inhibitors and among second-line therapies are VCDs which are clear plastic chambers placed over the penis, tightened against the lower abdomen with a mechanism to create a vacuum inside the chamber. This directs blood into the penis. If an adequate erection occurs inside the chamber, the patient slips a small constriction band off the end of the VCD and onto the base of the penis. An erection beyond 30 min is not recommended. These devices can be a bit cumbersome, but are very safe.40
In one study, 9.6% reported ‘occasional’ erectile dysfunction, 8.9% reported erectile dysfunction occurring ‘often’, and 18.6% reported erectile dysfunction occurring ‘all the time’. Of these, only 11.6% had received treatment.In another study, only 14.1% of men reported that they had received treatment, despite experiencing erectile dysfunction for longer than 12 months.
Oral therapies via the PDE5i sildenafil, vardenafil, and tadalafil have been proven to be generally safe and effective in select NED populations. The majority of the treatment effectiveness data has been generated in the SCI population. Data regarding the use of PDE5i outside of the SCI population is lacking (58). Furthermore, the ED that exists in the population with neurologic disorders is often multifactorial and may be caused by psychogenic, psychosocial, hormonal, medication-related and disability-related factors. A careful evaluation of each patient must be performed to isolate these factors prior to initiating vasoactive therapy.
ED exists in approximately 75% of men with SB and is dependent upon the level of the neurologic lesion (54). The level of the neurologic lesions usually corresponds to sensation and penile sensation indicates pudendal nerve signaling. With absent sacral reflexes ED is variable. Furthermore, Diamond et al. reported that 64% of men with lesions below T10 obtained erections versus 14% with a lesion above T10 (55). It has also been suggested that ED may be underreported due to lack of sexual education even in men without associated cognitive impairment (56).
Other treatment options such as penile self-injection therapy, external vacuum pumps and the medicated urethral system for erection are in rare occasions an effective long-term treatment. Only a very small percentage of men will continue with these treatments as evidenced by a very high drop out rate and a very low refill rate. These treatments require extensive planning which interferes with spontaneity. This may be the reason why the refill rate is so low and the drop out of treatment so high.
An alprostadil cream that patients apply into the tip of the penis (the urethral meatus, the opening that urine passes through) is currently available in the UK and Europe. It is currently under review by the U.S. Food and Drug Administration (FDA). After application of the cream, an erection occurs within five to 30 minutes, and the erection lasts one to two hours in men who respond to the cream. Doctors recommend that one use the cream for a maximum frequency of two to three times per week and no more frequent than once every 24 hours. It has essentially the same contraindications and side effects as the other formulations of alprostadil. The cream may cause vaginal burning in roughly 4% of partners. Men should not use alprostadil cream for sexual intercourse with women of childbearing potential unless a condom is used. Researchers have performed controlled trial studies to evaluate the safety and effectiveness of this drug. Overall, 52% of men reported improvement in their erections compared to 20% of men receiving placebo. A later analysis demonstrated that 36% of men using the alprostadil cream had a clinically relevant improvement in vaginal penetration ability and 31% clinically relevant improvement in ability to have successful intercourse to ejaculation.
Ultrasound with Doppler imaging (ultrasound plus evaluation of blood flow in the arteries and veins) can provide additional information about blood flow of the penis and may help in the evaluation of patients prior to surgical intervention. This study is typically performed after the injection of a chemical that causes the arteries to open up, a vasodilator (prostaglandin E1), into the corpora cavernosa in order to cause dilation of blood vessels and promote blood flow into the penis. The rate of blood flow into the penis can be measured along with an evaluation of problems with compression of the veins.
Some men report being helped by an oral medication called yohimbine, which comes from the bark of a tree that grows in India and Africa. This drug, which needs to be taken every day, has been reported to help about 20 to 25 percent of the men taking it. A relatively new but widely used oral medication called Viagra requires a careful medical evaluation by your doctor.
VIP is a neurotransmitter with regulatory actions on blood flow, secretion and muscle tone with intracorporal adenylate cyclase activation and smooth muscle relaxation. VIP has been shown to elevate cAMP intracellular concentrations without affecting cGMP levels. However, when VIP is given alone it may not induce erection and requires combination with phentolamine or papaverine for it to be effective (88). Common associated adverse effects were facial flushing and headache. VIP in combination with phentolamine is currently being used in the UK and Europe and is seeking regulatory approval for use in the United States.
With an inflatable implant, fluid-filled cylinders are placed lengthwise in the penis. Tubing joins these cylinders to a pump placed inside the scrotum (between the testicles). When the pump is engaged, pressure in the cylinders inflate the penis and makes it stiff. Inflatable implants make a normal looking erection and are natural feeling for your partner. Your surgeon may suggest a lubricant for your partner. With the implant, men can control firmness and, sometimes, the size of the erection. Implants allows a couple to be spontaneously intimate. There is generally no change to a man's feeling or orgasm.