The erectile dysfunction drugs, or ED drugs, have been around for quite some time, with the first being sildenafil citrate, also known as Viagra. However, it wasn’t until recently that these drugs truly started to take the world by storm. The discovery of a new peptide, termed testosterone peptide 5, or TP5, which increased the activity of the nitric oxide (NO) system in the body and subsequently increased the efficacy of Viagra and its derivatives, really changed everything. Since then, many new ED drugs have been developed and are currently being tested, with more being brought to market each year.

The most popular of these drugs are known as the phosphodiesterase-5, or PDE5, inhibitors. Essentially, these drugs increase the amount of cGMP in the body, which then results in more powerful and persistent erections. This class of drugs is generally more effective than Viagra at treating erectile dysfunction. There are also other classes of ED drugs, such as the apelin receptor agonist, which also increase cGMP levels but work differently than PDE5 inhibitors. Each of these classes of drugs has its benefits and drawbacks, but no one drug can treat all types of erectile dysfunction. So it’s important to try different drugs, such as the ones mentioned above, to find out what works best for your body.

How Do They Work?

The cGMP-increasing effects of testosterone peptide 5 and other similar drugs result in increased penile blood flow and thus harder and longer-lasting erections. The exact same effects occur with the use of Viagra and Cialis, but to a lesser extent. The reason behind this difference in effect is not exactly known, but it’s believed to be related to the presence of other, more potent and faster mechanisms of action, or MoAs, for ED drugs. Essentially, these other MoAs help the cGMP-increasing drugs exert their full therapeutic potential and allow them to work quicker and more effectively, leading to fewer side effects. It should also be noted that testosterone peptide 5 and similar drugs also have other, less potent MoAs, which contribute to their overall effectiveness. The following are the most common and potent MoAs for ED drugs.

Inhibitors Of Phosphodiesterase-5

This is the most popular class of ED drugs, with the only members of the class currently being sold being sildenafil citrate and tadalafil. Sildenafil citrate is the active ingredient of the widely-used drug Viagra┬«, while tadalafil is the active ingredient of the recently-approved drug Cialis┬«. These two drugs are both orally administered, and they work by inhibiting the effects of phosphodiesterase-5, or PDE5. As a result of this inhibition, cGMP levels increase, leading to greater blood flow into the penis and more powerful and sustained erections. Additionally, PDE5 inhibitors do not inhibit the effects of other hormones, such as angiotensin, which makes them a safer choice for patients already on other medication, such as blood pressure medication, as it’s conceivable that the effects of these hormones might cancel each other out. Finally, PDE5 inhibitors are generally well-tolerated and have few side effects, as most of their effects are concentrated in the tissue adjacent to the vasculature, or blood vessels.

Apelin Agonist

This class of ED drugs was recently approved by the FDA and is currently being marketed under the trade name Revatio. Apelin is a naturally occurring peptide that binds to and activates the apelin receptor, which is present throughout the body, particularly in the cardiovascular system. As a result of this activity, apelin agonists increase the contractility of the smooth muscle cells of blood vessels and other organs, such as the prostate. Since these cells are responsible for moving blood through the body, increasing their contractility results in increased blood flow and thus harder and more sustained erections. Interestingly, many men have found that apelin agonists do not always work perfectly well in treating their erectile dysfunction. It’s been reported that apelin agonists do not work for some individuals and actually cause ED in others, which is why this class of medication is not for everyone, especially since it is contraindicated for use in people with heart disease. Nonetheless, apelin agonists are a promising drug class for the treatment of erectile dysfunction, and new studies are planned to investigate their efficacy and safety further.

Direct Activators Of Nitric Oxide Synthase

PDE5 inhibitors and apelin agonists both increase cGMP levels, but they do so through different mechanisms. PDE5 inhibitors increase cGMP levels by inhibiting the breakdown of cGMP by phosphodiesterase-5. Apelin agonists do so by directly activating nitric oxide synthase, or NOS, which then results in increased synthesis and release of cGMP. Nitric oxide is a substance that plays a crucial role in blood vessel dilation and thus facilitates blood flow into the corpora cavernosa during erection. So although PDE5 inhibitors and apelin agonists both have beneficial effects for men with erectile dysfunction, they serve different purposes and are not interchangeable, at least not yet.

Who Should Avoid These Drugs?

People who are allergic to or have adverse reactions to sildenafil citrate or tadalafil should avoid these drugs. Additionally, people who take blood thinning medication, such as aspirin or warfarin, should also avoid PDE5 inhibitors and apelin agonists as taking these medications together might increase the risk of bleeding. Furthermore, people with a history of heart disease, heart failure, or stroke should avoid apelin agonists as these drugs might worsen their condition. Finally, people who are not able to produce enough of the enzyme phosphodiesterase-5 or are not efficient enough in using the medications that are available should avoid PDE5 inhibitors and consider trying apelin agonists instead.

When Should You Try These Drugs?

Sildenafil citrate and tadalafil are both available for use in men with erectile dysfunction who don’t respond well to other medication or who can’t take other medications, such as nitrates or aspirin, due to a concomitant disease, or condition. Sildenafil citrate is generally regarded as a first-line treatment for erectile dysfunction, with tadalafil being a preferred second-line therapy, while apelin agonists are generally used as a third-line treatment. So if you’re not sure whether or not ED medication will help you out, it might be a good idea to start out with sildenafil citrate and then, if necessary, move on to apelin agonists or tadalafil, but only after trying, and failing, to treat your ED with lifestyle changes and drugs that aren’t effective or have intolerable side effects.

Before we wrap up, it’s important to note that although these drugs are commonly used to treat erectile dysfunction, they aren’t always effective for everyone. As we’ve discussed, there are different causes of erectile dysfunction, and thus different treatments might be needed. If you’re not sure whether or not ED medication will help you out, it might be a good idea to consult with a doctor or a urologist, who can best advise you on the best course of treatment for your particular case.

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