Three hundred million. That’s the number of men globally who are expected to have erectile dysfunction or ED by 2025. ED or impotence can affect men of all ages, contrary to the perception that only elderly men suffer from it. In reality, as many as 5% of American men over 40 years old have complete erectile dysfunction. This means that they absolutely cannot achieve an erection, and therefore, cannot engage in penetrative sexual intercourse.
Erectile dysfunction has three components, the first of which has to do with low or no sexual desire. The second component involves difficulties in achieving a functional erection. The third component is about not being able to maintain tumescence long enough to achieve vaginal penetration, orgasm, or ejaculation. Fortunately, new treatments for ED are currently being developed, and these treatments target specific components of the condition.
In the past, when the various causes of erectile dysfunction were not yet fully known, there was a prevalent belief that the condition was caused by excessive masturbation. Psychotherapy was considered as one way to stop excessive masturbation. Hence, psychotherapy became the primary treatment for erectile dysfunction. However, while it is true that emotional or psychological factors cause some instances of ED, this is not the case for everyone.
After psychotherapy, penile prostheses became popular as the main treatment for erectile dysfunction. However, not everyone could get the treatment. Then in the ’80s, the trend shifted towards intracavernosal injection (ICI), which entails medication injected into the base of the penis. Although many men might think twice about aiming a needle to their sex organ, the truth is that drugs for ICI are still sold in the market, and many men continue to use ICI as their preferred ED treatment.
The ’90s saw the introduction of oral phosphodiesterase type 5 inhibitors (PDE5Is) in the form of Viagra. Since then, research on new and non-invasive ways to treat erectile dysfunction have been continuing. Levitra has been available in the market since 2003. Next came Staxyn, which was approved by the US FDA in 2010. Cialis was approved by the FDA in 2011, the same year when Stendra was made available on the market. Men who are suffering from erectile dysfunction can continue to look forward, as several other medications and new forms of treatments are in the pipeline.
New medications for erectile dysfunction are veering away from the PDE5I mechanism. The focus has shifted to dopaminergic and melanocortin receptor agonists. The first type works by activating dopamine receptors. Dopamine is a neurotransmitter released by the brain during sexual arousal. Thus, increasing dopamine levels and activating dopamine receptors trigger arousal and erection.
Melanocortin receptor agonists, on the other hand, are different from PDE5I in the sense that with melanocortin agonists, you can have an erection even without sexual stimulation. PDE5I, however, requires sexual stimulation before its pharmacological properties kick in. Unfortunately, in one trial involving 20 men with organic erectile dysfunction and ED caused by psychogenic factors, administration of a melanocortin receptor agonist drug led to frequent yawning and nausea, although the drug did show that it was effective in stimulating penile erection in 17 of the 20 male participants.
Nausea is also the reported side effect of a dopaminergic drug for ED that is currently available in European markets. Uprima (apomorphine) is yet to be approved for release in the United States. In its current form, Uprima is an oral tablet but trials are currently ongoing to test the drug in a nasal spray form.
Vasodilators like alprostadil are also used to help achieve an erection. Also a prescription drug, alprostadil is used either as an injection or a penile suppository. It is to be used as needed, such as before engaging in sexual intercourse. If injected, it may take 5-20 minutes before an erection may occur. If used as a suppository, it may take 5-10 minutes before it takes effect.
The problem with the prescription drugs used for the treatment of erectile dysfunction is that many are unable to take the medication due to contraindications with their ongoing medical conditions. For instance, if you have a preexisting cardiovascular disease, you’re not supposed to take any of the PDE5I drugs.
Because the contraindications with PDE5I drugs mean many men with erectile dysfunction can’t take the medications, experts explored other mechanisms and platforms to look for new ways to treat erectile dysfunction.
One treatment that was recently developed is called low-intensity shockwave lithotripsy. When first tested in animal models, low-density shock wave therapy was shown to have significantly improved penile blood flow and increased erectile function.
In diabetic animals with erectile dysfunction, the biggest advantage this therapy offered is that it was able to restore pathological changes in the penis caused by diabetes. This is something that PDE5I medications or vasodilators cannot accomplish. Moreover, shock wave therapy offers an option to erectile dysfunction patients who cannot take or do not respond to PDE5I medications.
When stem cell therapy was first developed for erectile dysfunction treatment, the idea behind it was that stem cells may be able to replenish or replace damaged endothelial cells and cavernous smooth muscle cells in the penis. These two types of cells actually play very important roles in erection.
Stem cell therapy for erectile dysfunction has been tested in animals through various trials and studies. Recently though, several trials involving human participants have been conducted. One of the first tests was conducted in 2010 in Korea. Seven men who had diabetes-related erectile dysfunction were given a penile injection of umbilical cord stem cells. Two months after the treatment, only one of the seven patients did not report experiencing morning erections while the other six patients did.
In 2016, three more trials were conducted by separate research groups. One group had participants suffering from organic erectile dysfunction. The second group’s participants were men who had ED 5-18 months after radical prostatectomy, while it was 22 months after the procedure for the third group.
The three trials also used stem cells from different sources – bone marrow stem cells, adipose-derived stem cells, and placental-derived stem cells. All three studies showed promising results, indicating that stem cell therapy may soon become a mainstream treatment for erectile dysfunction.