Medically reviewed by: Thomas Fischer (Pharmacist). This article has been written according to strict guidelines and medical standards.
Medically reviewed by: Thomas Fischer (Pharmacist)
PDE-5 (Phosphodiesterase Type Five) inhibitors are a group of drugs developed to counter the symptoms of erectile dysfunction (ED).
1989 saw the development of the first PDE-5 inhibitor. Pfizer pharmaceuticals produce it. The drug was patented as sildenafil and introduced to the market as Viagra in 1998. Since then, three more PDE-5 inhibitors have been developed and added to the market.
The discovery of PDE-5 inhibitors has been a revelation to men that live with ED. Many of these men view this kind of medication as a miracle drug. This is because it has given them back their dignity and altered their sex life.
But, how do these drugs work, and are there risks involved in taking them?
Which Active Chemicals Do We Classify As PDE-5 Inhibitors?
There are currently four active chemicals on the market classified as PDE-5 Inhibitors. These are:
- Sildenafil - Developed in 1989 by Pfizer pharmaceuticals. It was first introduced to the market in 1998 under the brand name Viagra.
- Tadalafil - Developed and manufactured by Eli Lilly and Co. and sold under the Cialis brand name.
- Vardenafil - GlaxoSmithKline, Schering-Plough, and Bayer pharmaceuticals co-developed vardenafil. It sells as Levitra on the open market.
- Avanafil - Known as the trademark brand Stendra. Mitsubishi Tanabe Pharma designed this chemical.
Regardless of subtle differences, PDE5 inhibitors all function in similar ways. The main application for these drugs is to counter the effects of impotence.
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PDE-5 Inhibitors - Areas Of Application
The principal use for PDE-5 inhibitors is to combat the symptoms related to erectile dysfunction.
However, it’s not the only condition for which PDE-5 inhibitors are useful. Due to its vasodilatory effect, PDE-5 inhibitors have also been efficient in treating pulmonary arterial hypertension (PAH – high blood pressure in arteries leading from the lungs to the heart) as well as Benign Prostatic Hyperplasia (BPH – prostate gland enlargement).
Although further testing is needed, clinical studies have revealed that PDE-5 inhibitors also show potential in the treatment of cystic fibrosis, heart failure, CNS-related diseases, diabetes, cancer, Raynaud’s phenomenon, and male reproductive/urinary system dysfunctions.
PDE-5 Inhibitors - How Do They Work?
In healthy men, sexual arousal produces nitric oxide. This substance is necessary to manufacture cGMP enzymes in the penile area, which allows for blood vessel expansion and contraction. This, in turn, causes the blood flow into the phallus to increase, which results in an erection.
After ejaculation, PDE type 5 enzymes neutralize the cGMP enzymes, which results in blood flowing out of the penis returning it to its normal state.
An abundance of PDE type 5 enzymes are present in men with erectile dysfunction, which interferes with the natural order of things.
This is where PDE-5 inhibitors come into play. These inhibitors prevent the PDE type 5 enzymes from neutralizing the cGMP enzymes, which allows for the natural process to occur unhindered.
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How To Use PDE-5 Inhibitors
PDE-5 inhibitors are typically used as the active ingredient in various drugs available on the market. These drugs are usually produced in the form of a pill that is taken orally and only when needed.
Depending on the drug you have been prescribed, it needs to be taken anywhere from thirty minutes to two hours before intercourse.
Tadalafil based drugs, however, are the exception. Due to tadalafil’s long-lasting effect, it can be taken several hours before intercourse. Your doctor can also prescribe tadalafil as a daily medication. In this case, you need to take one pill at approximately the same time every day.
PDE-5 Inhibitors - Side Effects
The four PDE-5 inhibitors generally have the same side effects. The most common of these include:
- Facial flushing
- Headaches
- Vision abnormalities including blurred vision and altered color perception
- Acid reflux
- Upset stomach
- Muscle pains
- Backache
- Stuffed or runny nose
- Allergic reactions include hives, rash, itching, impaired breathing, and swelling of the face, eyes, tongue, lips, or throat
- Sudden impairment or loss of vision
- Chest pain
- Priapism (painful and prolonged erections lasting more than four hours)
- Seizures or fits
PDE-5 Inhibitors - Drug Interactions
Several drugs may cause interactions when used in combination with PDE-5 inhibitors. The result may be anything from mild to severe. However, it is best to avoid combining erectile dysfunction medications with drugs that may interact with it.
The most common of these interactions include:
- Nitrate and nitrite treatments
- HIV protease inhibitors
- Itraconazole
- High blood pressure medication
- Alcohol
It is crucial that you consult with your doctor before you start to use a PDE-5 inhibitor. This will help to avoid drug interactions. These clashes may result in renal failure, heart attacks, or strokes. In extreme circumstances, it may result in death.
Contraindications Associated With The Use Of PDE-5 Inhibitors
There are some contraindications associated with PDE-5 inhibitors. These include:
- The use of PDE-5 inhibitors are contraindicated in patients who are receiving nitrate treatments. It enhances the hypotensive action of nitrates, which can lead to a severe and sudden drop in blood. This may result in a stroke, heart attack, or renal failure and may be life-threatening.
- The use of erectile dysfunction drugs should be avoided by men that are allergic to any substance that forms part of the medication’s composition. Severe allergic reactions are severely uncomfortable and potentially life-threatening.
- Men that are using alpha-blockers should also use caution when taking PDE-5 inhibitors. The combined use may result in a significant decrease in blood pressure.
For a comprehensive list of contraindications and side effects, consult the leaflet that accompanies the packaging.
Contraindicated use of PDE-5 inhibitors can be life-threatening and should be avoided at all costs.
Are PDE-5 Inhibitors (Cialis, Viagra, Levitra, and Stendra) Available Over the Counter?
In certain European countries, including the UK, erectile dysfunction drugs, or PDE-5 Inhibitors are sold as over the counter (OTC) products.
However, due to FDA regulations in the United States of America, the OTC sale of PDE-5 inhibitors are prohibited. This rule also applies to the import of PDE-5 Inhibitors that were bought without a prescription.
Are PDE-5 Inhibitor Drugs Available To Buy Without A Prescription?
Different countries have different medication regulations. There are some countries, like the UK, that allow the sale of erectile dysfunction medication without a prescription.
If you are willing to risk it, you can search for an online pharmacy that operates from within a country that allows the sale of PDE-5 inhibitors without a prescription. You should take note that this action is ill-advised.
The odds of finding a legitimate pharmacy that sells OTC PDE-5 Inhibitors are against you. There are many risks and dangers involved when you’re dealing with rogue pharmacies. Quite a few of these risks may end up costing you your life.
It is illegal to import or buy erectile dysfunction drugs over the counter in the USA.
The Risks Involved With Ordering PDE-5 Inhibitors Without A Prescription
There are a number of risks involved with ordering prescription-only medication online without a doctor’s script.
Due to its popularity, criminal organizations profit from the mass production of counterfeit PDE-5 drugs. They then sell these drugs to the unknowing public as the original product. This poses potentially severe health risks for the individuals that use these drugs.
Illicitly prepared drugs have also been known to contain different medications not listed on the packaging. This may lead to interactions with other medicines and conditions and can also cause allergic reactions.
Rogue pharmacies are also prone to selling substandard medications. These drugs typically contain either more or less of the active ingredient than is displayed on the packaging. This may result in the product not working effectively or, going the other way, an overdose of the substance.
Many of the so-called online pharmacies also act as phishing scams. If you enter your personal details on these sites, you expose yourself to identity theft. Cybercriminals steal your personal information to commit crimes in your name and also to drain you financially. It may take years to recover from identity theft.
Then there’s also the possibility of being caught by the authorities for bringing contraband products into the country. If found, you may receive a fine or possibly some jail time.
All in all, the risks involved when buying PDE-5 inhibitors without a prescription are far higher than the rewards. It is a fool’s errand.
Online - Where To Order PDE-5 Inhibitor Drugs
There are thousands of online pharmacies and internet health care clinics on the web. The problem is that criminals operate many of these websites, and buying your erectile medication through them is not a good idea.
So, how do you choose a legitimate online pharmacy?
First, it is essential to know what to avoid. Start by eliminating any website that offers the sale of PDE-5 inhibitors without a prescription. Although some of these sites are legit, the gross majority of them aren’t.
Check the spelling and grammar of the site. Start by looking at the website address bar and then scan the welcome page. Criminals, in general, aren’t bothered with proper grammar or correct spelling. Typically these errors are a dead give away.
Next, look at the website protocol. Rogue sites often use the Http:// protocol, which is not a secure connection, so be sure to check that the website you are about to business with uses the Https:// protocol. Also, check for the padlock in the address bar. This is further proof of a safe site.
Other things you can check to guarantee that the website is trustworthy include trust seals, independent reviews, scam review sites, and a contactable telephone number or physical address listed on the website.
Once you are sure that the website is trustworthy, you are good to go. Ordering your medication from these sites is a straightforward procedure.
Logon on to the site you have chosen, register an account, and electronically forward your prescription to the online pharmacy. Next, select the product and the quantity you desire and add it to your shopping basket. Now proceed to the payment page.
As soon as your payment is approved, the chemist will make up your order and package and send it to you via courier or postal services, typically as overnight delivery. Your medication should be delivered to your residence within twenty-four hours.
Alternatively, if you don’t yet have a prescription, the telehealth site will have a doctor available to assist. Complete an online form, have a consultation via phone or video, and the script is generated for you. They’ll then dispatch your medication automatically.
It is crucial that you avoid dealing with online pharmacies, which can not be verified.
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