Viagra Side effects and contraindications

Viagra is one of the most controversial and widely discussed pharmaceutical drugs to hit the market in the last 30 years. For the treatment of erectile dysfunction, men most often use Viagra or its analogues.

What is Viagra

Viagra is the brand name for sildenafil citrate, used to treat impotence and pulmonary arterial hypertension. The main drug relaxes the walls of the blood vessels of the penis, thereby contributing to a full erection. In most cases, Viagra works effectively and changes men's lives for the better.

The chemical formula of sildenafil citrate is C22H30N6O4S. The compound was discovered by scientists in the UK, originally working on a cure for hypertension or high blood pressure, and for angina pectoris, a symptom of coronary heart disease, and marketed by the American pharmaceutical company Pfizer Inc. During the first phase of the trial, it was noted that the drug was not effective enough against angina pectoris, but it caused a noticeable erection of the penis.

Introduced to the market in 1998, Viagra was the first oral therapy for erectile dysfunction to be approved in the United States. Already in 2008, the sale of this drug brought Pfizer about $1.93 billion in revenue. Viagra is also sold under the brand name Revatio.

In this article, you will get acquainted with the principle of the drug, with the rules for taking it, side effects and contraindications.

How the drug works

Originally, the drug was developed to lower blood pressure, but now it is used to treat erectile dysfunction. Viagra helps men who cannot get or maintain an erection due to erectile dysfunction.

Sildenafil improves the erectile response when a man is already sexually stimulated, but the drug itself does not provide sexual arousal. If there is no such stimulation, then Viagra will not work.

When a man is aroused, nitric oxide is released in the erectile tissue of the penis. Nitric oxide stimulates the production of a special enzyme called cyclic guanosine monophosphate (cGMP). It, in turn, causes the arteries to expand, which helps the vessels and cavernous bodies of the penis to fill more fully with blood.

The point of using sildenafil is that it blocks the action of another enzyme, phosphodiesterase type 5 (PDE5). The action of PDE5 interferes with the work of cGMP, and sildenafil eliminates this negative effect. Viagra, as a drug, the main ingredient of which is sildenafil, prevents the breakdown of cGMP and provides blood supply to the penis. The result is a persistent erection.

Dosage How to take

Viagra is available in blue diamond-shaped tablets in dosages of 25, 50 or 100 mg.

The standard dose is 100 mg.

It is recommended to take the tablet with water approximately 30 minutes 1 hour before the planned sexual intercourse.

The maximum allowable dose of the drug is 100 mg for 24 hours.

A larger amount of Viagra taken does not affect the result, but it can lead to serious complications.

At the same time, the number of recorded deaths from an overdose is one among hundreds of thousands of users.

Side effects

If you follow the rules of admission and follow the doctor's recommendations, Viagra is considered a safe remedy. However, its intake can cause a number of adverse consequences for the body.

According to the results of clinical trials, the most common side effects of Viagra include:

• Headaches
• Nasal congestion
• Impaired vision
• Photophobia or sensitivity to light
• Upset stomach

Rarely, some users experience cyanopsia, a condition in which everything around them appears to be tinted blue.

In very rare cases, the use of Viagra can lead to non-arterial anterior ischemic optic neuropathy or damage to the optic nerve.

Other potential side effects of Viagra include:

• priapism painful, prolonged erection
• heart attack
• ventricular arrhythmias
• increased intraocular pressure
• since 2007 labeling Viagra in the US includes a warning about the potential risk of sudden hearing loss

Also, Viagra can reduce the blood supply to the optic nerve, causing sudden loss of vision. This very rare occurrence occurs mainly in men with heart disease, hypertension, diabetes, high cholesterol, or pre-existing vision problems. The mechanism of the link between vision loss and Viagra has not yet been studied.

Interaction with other drugs

Men with HIV taking protease inhibitors should consult their doctor about using Viagra. These drugs increase the risk and severity of side effects. Such patients should take no more than 25 mg of Viagra at a time, and no more than 48 hours later.

Persons taking alpha-blockers, for example: tamsulosin, should use Viagra at least 4 hours before or after taking them. This will help avoid the risk of a dangerous drop in blood pressure.

The same applies to preparations containing nitrate compounds, for example: nitroglycerin. Their combined use with tablets containing sildenafil can lead to a critical drop in pressure.

Contraindications

Sildenafil is contraindicated for men with the following diseases:

• severe liver failure
• kidney disease
• low blood pressure (hypotension)
• recent heart attack or stroke
• hereditary degenerative retinal disease
• patients advised to abstain from sexual intercourse due to cardiovascular risk factors

If you have at least one disease from this list, you should definitely consult with your doctor about the possibility of using Viagra or any of its analogues.

What is Revatio

For the treatment of pulmonary arterial hypertension, sildenafil is available in the form of round white coated tablets. People take one Revatio 20mg tablet three times a day.

Some athletes are known to use Revatio to increase their physical performance, but there is very little evidence to support the effectiveness of this method.

Overdose

An overdose of Viagra can have serious consequences. Overdose symptoms include:

• vomiting
• diarrhea
• blurred or distorted vision
• optic neuropathy optic nerve damage
• tachycardia increased heart rate
li>
• priapism prolonged erection without sexual arousal
• blindness
• rhabdomyolysis destruction of muscle tissue
• drastic drop in blood pressure

In any of these cases, you should immediately seek emergency medical attention.

Who should not use Viagra

The skyrocketing popularity of Viagra has led it to be widely used by perfectly healthy men without symptoms of erectile dysfunction to impress their partners.

Although the researchers note that in this case there is a placebo effect, there is no strong evidence of additional benefits in the duration of erection or the size of the erect genital organ.

Similarly, there is no proven benefit for women taking the drug.