PDE5 inhibitors are a class of medications used to prevent erectile dysfunction and pulmonary arterial hypertension. Such drugs work by inhibiting the enzyme phosphodiesterase-5, which degrades cyclic guanosine monophosphate, a smooth muscle relaxant, in the penis, causing blood flow and hence erection. PDE5 inhibitors are first-line drugs for erectile dysfunction and seem to be extremely effective in treating sex dysfunction. We’ll cover in this paper some of the most frequently used PDE5 inhibitors, applications, side effects, and warnings.
What is a PDE5 inhibitor?
PDE5 is an enzyme in the body that breakdowns the chemical present in the body, called cyclic guanosine monophosphate; PDE5 inhibitors stop that process. Nitric oxide, NO, leads to a cascade-like effect that leads to the release and intracellular concentration of cyclic guanosine monophosphate, or cGMP, the real substance responsible for smooth muscle relaxation, dilatation of arteries and increase in blood flow to the penis. These medications will not work without sexual stimulation and are not aphrodisiacs.
The three most widely used PDE5 inhibitors are sildenafil (Viagra), tadalafil (Cialis) and vardenafil (Levitra). Each of these three medications function in a similar way and are approved for use in ED by the U.S. Food and Drug Administration (FDA). All of them are prescription drugs that are taken orally.
Sildenafil (Viagra)
The first PDE5 inhibitor to be approved by the US Food and Drug Administration (FDA) for ED was Viagra, a brand name for sildenafil citrate, in 1998. It works by preventing the enzyme PDE5 from breaking down cyclic guanosine monophosphate (cGMP), a second messenger that regulates blood flow in the corpus cavernosum of the penis. Through its blockade of PDE5, sildenafil enhances the action of nitric oxide (NO), a potent vasodilator, thereby promoting a greater supply of blood to the penis and enabling an erection.
Sildenafil should be administered orally, in doses of 50 mg if needed, 1 hour before sex. The dose may be reduced to as much as 100 mg, or increased to 25 mg, depending on how the patient responds and tolerates it. Sildenafil has a half-life of approximately 4 hours and the effects last up to 6 hours.
Tadalafil (Cialis)
Tadalafil, which is marketed under the brand Cialis, is a second-generation PDE5 inhibitor approved by the FDA in 2003 for the treatment of ED. Tadalafil’s half-life is longer than sildenafil and vardenafil’s (about 17.5 hours) and its effects can last up to 36 hours. Tadalafil’s longer effect duration has earned it the tag ‘the weekend pill’.
Tadalafil is usually prescribed at 10 mg a day and taken orally, as directed, about 30 minutes before sexual activity. The amount of dose can be increased up to 20 mg, or decreased to 5 mg, depending on the response and tolerability of the patient. Tadalafil is also sold in 2.5 or 5 mg doses daily for the treatment of ED in men who plan to have sex twice or more per week.
Vardenafil (Levitra)
Vardenafil, marketed under the name Levitra, is a second-generation PDE5 inhibitor approved by the FDA for the treatment of ED in 2003. Vardenafil has a half-life of four to five hours (similar to sildenafil), and the effects can last as long as six hours.
Vardenafil should be taken orally, at 10 mg per day, as needed, approximately an hour before sex. Depending on patient response and tolerance, the dose can be increased up to 20 mg or decreased to 5 mg. Additionally, Vardenafil is also available in a chewable tablet form that can be taken without water.
Other PDE5 inhibitors
Aside from these 3 medications, other PDE5 inhibitors include avanafil (Stendra) and udenafil (Zydena). These drugs share the same mechanism of action and have proven to be useful in the treatment of ED. Yet, they are less commonly used than sildenafil, tadalafil, and vardenafil.
Although PDE5 inhibitors are a promising treatment for ED, they do carry risks.
PDE5 Inhibitors: Benefits and Side Effects
PDE5 inhibitors are prescription drugs that are widely used to treat erectile dysfunction. Over the years, they have become immensely popular for their efficacy in erectile dysfunction and their relatively low side effects. But before participating in the treatment with drugs belonging to the group, one needs to consider some of the things and side effects that could happen.
Importance of Consultation
And above all, when using PDE5 inhibitors, talk to your healthcare provider. Usually, it is going to depend largely on your own medical history as to whether you take these medications or not. Some men who suffer from disease, particularly heart diseases, should exercise extreme caution. PDE5 inhibitors also improve blood flow and blood pressure, which could be problematic with heart disease or even post-heart-attack periods.
Similarly, PDE5 inhibitors should not be taken by anyone taking nitrates for angina and other heart problems. Combining the two classes of drugs creates deadly hypotension, or dangerously low blood pressure. This is why it’s critical to ensure that individuals inform their health care providers about their past and current medications.
Common Side Effects
While the PDE5 inhibitors are well tolerated by most men, it must be acknowledged that they do come with their share of side effects. The majority of these effects are mild, and include the following:
Headaches : The most prominent side effect may have to do with the blood flow and the changed dynamics of the blood vessels caused by these medications.
Flushing: This feels like a heat or redness on the face, neck, or chest, usually in conjunction with a drug like sildenafil.
Digestion: Some people suffer from gastrointestinal upset (heartburn, nausea) during or after use.
Nasal congestion: Increased blood flow in the area may cause the passages to clog temporarily, or the nose become stuffy.
Sildenafil has fewer, but more serious, visual disturbances. A human might be aware that certain colours, notably blues and greens, might look different.
These are generally not life-threatening, but they can affect a person’s quality of life. These could be all it takes for a person to stop taking medication. You should speak with your physician about any side effects because a patient may have an alternative.
Contraindications and Allergies
In addition, you have to make sure that PDE5 inhibitor-associated patients who have any known contraindications or allergies don’t take the drug. That’s because any prior disorder or allergy to a compound will lead to an unintentional reaction that may be further jeopardizing a patient’s health. Another condition that the patient will need to report to a healthcare provider is any priapism or painful erection that lasts longer than four hours that PDE5 inhibitors might exacerbate.
Conclusion:
The most common and effective approach for treating ED involves PDE5 inhibitors. The three most commonly used of these drugs, the drugs Sildenafil, tadalafil and vardenafil, have been shown to improve sex very effectively. But they are also susceptible to side effects and precautions. Therefore, they are best consumed under a physician’s supervision. The patient should share all of his fears or concerns with a medical professional prior to the beginning of treatment.
