Category - Part 2
Medical treatment of erectile dysfunction: Other treatments
ORAL AGENTS
Trazodone
The antidepressant trazodone was noted to occasionally induce priapism and therefore interest developed in its possible role in treatment of erectile dysfunction. There are reports of good erectogenic activity with trazodone, although no significant benefit was found in a placebo-controlled trial. There are also troublesome side-effects, including drowsiness, orthostatic hypotension, nausea and vomiting.
Sildenafil (Viagra®)
Sildenafil is a novel oral therapy currently under active investigation. It is a specific inhibitor of type 5 cGMP phosphodiesterase, which is the predominate isoenzyme in the cavernosal tissue of the penis. Its inhibition leads to increased local levels of the secondary messenger cGMP, leading to relaxation of smooth muscle in the cavernosal tissue. This in turn increases blood flow into the corpora cavernosa, an essential stage in the erectile process. In a double-blind cross-over study of 12 patients with erectile dysfunction of no established organic cause, an objective dose-dependent increase in erectile activity as determined by plethysmography (RigiScan, Dacomed Corporation, MN, USA) was demonstrated. Ten of 12 patients reported improved erectile activity in the sildenafil group compared with two of 12 taking placebo. In another double-blind placebo-controlled study of 351 men with erectile dysfunction, outcome by patient and partner questionnaire confirmed a significant dose-dependent improvement on erectile activity. Side-effects such as facial flushing, headaches and dyspepsia were rare and mild. Sildenafil seems to be efficacious and safe and will undoubtedly play a major role in the treatment of erectile dysfunction in the future. Buy Viagra Professional
External vacuum devices
For patients with erectile dysfunction who cannot tolerate or do not respond to intracavernosal injections, there is a choice between a penile prosthesis or a vacuum device. A vacuum device works by creating penile congestion and enough rigidity to allow penetration (figure l). There are no comparative controlled studies and most of the questionnaire reviews are carried out by the manufacturers themselves. However, a satisfaction rate of 70% was reported by Price in diabetics, who also emphasized the importance of a stable relationship for success. One major disadvantage to the patient is that these devices are not available on the National Health Service and cost £200 or more. Of the 60% who were able to get an adequate erection, only one third purchased a device, claiming price as the limiting factor. There are few side-effects; some complained of pain and bruising at the site of the constricting rubber ring at the base of the penis and in a minority the partner found it an unacceptable method.
Although not universally popular, for some patients who cannot tolerate intracavernosal injections or are too elderly or unfit to be offered a penile prosthesis, a vacuum device may be a very effective treatment and it does not carry the risk of priapism.
Testosterone replacement and supplementation
Testosterone can be given orally, by injection or implant, and now by a transdermal route (patch). Oral administration of testosterone is an unreliable route for increasing testosterone levels and injections or implants, both invasive techniques, are needed to sustain increased levels. The testosterone patch is a convenient and noninvasive method of obtaining controlled and sustained increases in testosterone levels. However, the use of the testosterone patch has been limited to date, probably because of problems with skin irritation.
INTRACAVERNOSAL AGENTS
Vasoactive intestinal polypeptide and phentolamine
Vasoactive intestinal polypeptide (VIP) is a postganglionic neurotransmitter which seems to have a role in the erectile process. VIP is described as a ‘facilitator’ of erections because intracavernosal injection leads to tumescence only. A combination of VIP and phentolamine can be very effective. In a study of 52 men with erectile dysfunction of mixed aetiology but full response to papaverine, intracorporeal injection of 30 ug of VIP and 0.5-2 mg of phentolamine led to a functionally rigiderection in 100% of cases. At 6 months follow-up no patient had complained of pain or suffered a complication such as corporeal fibrosis or priapism. VIP and phentolamine would seem to be a very promising, safe and efficacious treatment for erectile dysfunction and maybe an especially important alternative for patients who suffer PGEl-induced pain. At present this combina tion is currently only available on a named-patient basis in hospitals.
PROSTAGLANDIN El (PGEl)
Effectiveness
There are a multitude of publications on the use of PGEl. One large multicentre trial of 187 patients with erectile dysfunction reported good or very good patient satisfaction in 91% of patients. In a study by Stackl of 550 sufferers, 70% reported a full erection lasting for more than 30 minutes and all were adequate for vaginal penetration. More recently, in an open flexible-dose study of 683 men with erectile dysfunction, 11 924 of 13 762 PGEl injections given (87%) resulted in a satisfactory sexual performance. Satisfaction rates of between 77% and 86% amongst partners was also reported.
Medical treatment of erectile dysfunction
There has been a tremendous increase in demand for the treatment of erectile dysfunction in the last 10 years. This has occurred partly because of a greater understanding and awareness by both the general public and clinicians, and also because there now exists a range of effective treatments. The choice of treatments is increasing rapidly and novel delivery systems which may be more patient-friendly than intracavernosal injections are now becoming available. We review the published data on effectiveness and safety of the currently available treatments and discuss recent advances in oral therapy, as these drugs are likely to become available in the near future.
FDA Approves Third Drug To Treat Erectile Dysfunction
The Food and Drug Administration (FDA) today approved Cialis (tadalafil), an oral medication to treat erectile dysfunction (ED, or impotence) in men. This is the third oral product approved for this condition. This drug is different than currently approved products for ED in that it stays in the body longer.
Erectile dysfunction (ED) affects millions of men in the United States. Cialis acts by relaxing muscles in the penis and blood vessels, allowing increased blood flow into the penis, which produces an erection.
Canadian Cialis was evaluated in randomized, placebo-controlled trials involving more than 4,000 men with erectile dysfunction. In two of these trials, men had ED associated with diabetes mellitus or following radical prostatectomy for prostate cancer.
The drug’s effectiveness was assessed using a sexual function questionnaire. In addition, patients were asked to report if they were able to achieve an erection adequate for intercourse and whether that erection was maintained to allow completion of intercourse. In all of these trials, Cialis pills improved patients’ ability to achieve and maintain a penile erection. In other studies, sexual activity was improved in some patients at 30 minutes after taking a dose; additional studies demonstrated improvements for up to 36 hours after taking Cialis when compared to placebo.
The recommended starting dose for most patients is 10 mg taken prior to anticipated sexual activity. A higher dose of 20mg is available for patients whose response to the 10mg dose is not adequate. A lower dose (5 mg) is also available and may be necessary for patients taking other medicines or having medical conditions that may decrease the body’s ability to metabolize tadalafil. Cialis tablets should not be used more than once per day.
Cialis should not be used with nitrates (such as nitroglycerin tablets or patches) or with an alpha blocker other than FLOMAX 0.4 mg daily (alpha blockers are medicines used to treat benign prostatic hyperplasia and high blood pressure) because the combination may significantly lower blood pressure and lead to fainting or even death in some men.
Because some drugs affect the metabolism of Cialis, patients should inform their doctors that they are taking Cialis. For example, patients taking ketoconazole or ritonoavir should not take more than a 10mg dose of Cialis once every 72 hours.
Also, in patients with moderately or severely decreased kidney function, the starting dose is 5mg taken once daily. In this group, the dose may be increased to 10mg taken once every 48 hours. In patients with mild or moderate liver impairment, the maximum dose of Cialis is 10mg.
In most patients, after taking a single dose of generic Cialis, some of the drug will remain in the body for more than 2 days. In those with decreased kidney function, impairment of the liver, or those taking certain medications (e.g. ketoconazole or ritonavir) tadalafil can remain in the body longer.
Cheap Cialis should not be taken by men in whom sexual activity is inadvisable because of their underlying cardiovascular status (heart condition). Patients should inform their doctor about any heart problems that they have experienced before taking Cialis.
Generic Cialis is not recommended in patients who have suffered a heart attack or stroke within the last six months, or patients who have significantly low blood pressure, uncontrolled high blood pressure, unstable angina, severe liver impairment, or retinitis pigmentosa (an eye disorder).
The most common side effects reported in clinical trials included headache, indigestion, back pain, muscle aches, flushing, and stuffy or runny nose. Patients who get back pain and muscle aches usually get it 12 to 24 hours after taking generic Cialis and these usually go away by themselves within 48 hours. A small number of patients taking Cialis also reported abnormal vision.
Before taking Cialis drugs, patients are advised to undergo a thorough medical history and physical examination to attempt to diagnose the underlying cause of the erectile dysfunction and to identify appropriate treatment.
Source: FDA Talk Paper #T03-79, November 21, 2003