Viagra (Sildenafil): How to take, Side Effects, Properties

Viagra is used mostly in the treatment of erectile dysfunction in men. The active component responsible for the action of Viagra is called Sildenafil Citrate and it belongs to a class of PDE5 inhibitors. Studies have shown that Viagra can be also successfully used for a variety of other diseases, such as pulmonary hypertension, thanks to the vasodilation it causes in pulmonary vascular pathways. Pulmonary vascular is a common term for diseases that happen in the blood vessels on the route between the heart and the lungs.

How and when to take Viagra?

Always follow the directions on the package of the Viagra pill you have obtained. You should not take a larger amount of the pill of Viagra than what was prescribed for you. While there is hardly a possibility of the Viagra overdose, a number of undesired outcomes may occur if you increase the dosage prescribed.

Viagra is normally taken only when needed, that is, if the absence of an erection is observed. A patient should take Viagra from 30 minutes to 1 hour before pre-planned sexual activity. One hour will allow an active component Sildenafil citrate to be absorbed in the system of a patient and to show its full potential. However, a patient may take a Viagra pill up to 4 hours before sexual activity.

Viagra is not to be taken more than once per day, unless otherwise recommended by the physician.

After taking Viagra and during sexual activity, if a patient feels nausea, or has pain, numbness sensations in muscles, a patient is advised to stop sexual activities and call a doctor right away.

Can you get Viagra without going to the doctor?

As of today, in the United States and Canada, as well as in the majority of other countries across the globe, Viagra is sold only with prescription at pharmacies. The same prescription-only rule applies to all Viagra’s popular counterparts, like Cialis, Levitra, and some others. You can see the prices of generic Viagra from Canadian pharmacies on the Pharmos corporation website: pharmoscorp.com/erectile-dysfunction/generic-viagra.

When a medication become available widely not only by prescription it is titled an over-the-counter drug. There are existing means to obtain medications for erectile dysfunction online prescription-free but these often turn out to be counterfeit or contain “modified” components of questionable quality and of less-than-sure efficacy.

The attempts of the pharmaceutical companies to legalize prescription-free availability for Viagra, Cialis, or Levitra as over the counter drugs failed short in the United States and Canada. Even in European countries for the manufacturer of Viagra, the German company Pfizer, it was impossible to get a permission to sell a popular erectile dysfunction treatment as an over the counter drug available for anybody who walks in the store and asks for it. Among the reasons for the disapproval were concerns about the potential misuse, the extensive educational material required to accompany the drug, and the statistics that were saying that the underlying medical conditions that lead to erectile dysfunction would go basically untreated even when tricked by Viagra.

The same outcome awaited other treatments except Viagra. With one notable exception:

Sanofi, the French company that had the exclusive rights to market Cialis as an over the counter medication. When off patent, Sanofi can use its right to create all applications for over the counter approval in the countries of the European Union, in the United States, Australia, New Zeland and Canada.

In the recent years, there have been increased demand for the generic versions of Viagra. The generic versions of Viagra are usually made in India and are coming to the North American pharmaceutical market at the wholesale price, making the online retail price of a drug much lower than that of a branded pill. However, a consumer should be aware that, while generics do not have to be sold with prescription, they are subject to counterfeit or mis-dosage of an active component. Make sure to ascertain that the online seller you are thinking to purchase the generic Viagra from is legitimate.

Viagra (Sildenafil) Properties

The rate of absorption

Viagra is a very rapidly absorbed drug. When you are administering Viagra orally, your peak plasma concentration is about 30 to 90 minutes (when a drug is taken on an empty stomach), with the peak time averaging in about 60 minutes.

Metabolization

Viagra is largely metabolized by the liver. There are the pharmacological effects that show when the drug is taken in combination with other drugs, and can occur because of the Viagra in the liver.

Excretion

Viagra is excreted primarily in the stool with the extremely small portion excreted in the urine.

Pharmacodynamics

Viagra (sildenafil citrate) is PDE5 inhibitor (phosphodiasterese inhibitor). If we block PDE5, the metabolization in cGMP allows causing vasodilation which in its turn is used in the achievement of an erection.

If you have too much of PDE5 inhibitor, it would inhibit cGMP from allowing the release of an enzyme, that causes the release of vasodilation and then helps to achieve an erection. That is to say, too much of PDE5 with no matter how much parasympathetic stimulation one gets, and an erection cannot possibly be achieved or maintained for a sufficiently long time.

Where to store Viagra?

Store Viagra at room temperature away from moisture and heat.

Do we need sexual stimulation for Viagra to work?

As a matter of fact, sexual stimulation is a prerequisite to ensure a Viagra pill would work. A common myth of Viagra is that it is a magic pill that helps with an erection no matter what, under any circumstances.

The truth is, Viagra simply an enhancer of naturally occurring biochemical and physiological processes in the male organism that affect erectile functions. Viagra is efficient only when with the presence of psychogenic stimulation, or simply, the desire to have sex, and reflexive stimulation an erection do not occur for some reasons.

Adverse effects

Common side effects of taking Viagra include:

  • Face flushing. Caused by systemic vasodilation;
  • A mild headache. Caused by systemic vasodilation;
  • Nasal congestion. Caused by systemic vasodilation;
  • Heartburn.

Less common side effects of Viagra include:

  • diarrhea;
  • urinary tract infection;
  • blue-tinged vision;
  • increased light sensitivity;
  • priapism.

Very rare side effects of Viagra include:

  • Non-arthritic anterior ischemic optic neuropathy.

In extremely rare case taking Viagra can cause permanent blindness. In the majority of cases this adverse effect occurred, it was in concurrence with underlying anatomic or vascular factors. (Such as a patient may be older than 50 years old, suffer from diabetes, hypertension, and others).

Interactions

Viagra is metabolized by the liver, so naturally, interactions can occur with all the medications that are also metabolized by the liver. Some of the drugs are antifungals that are metabolized in that way. What happens with these drugs, they are antifungal agents inhibiting the metabolism of Sildenafil citrate and causing elevated plasma levels which can increase the risk of adverse effects.

Interactions with macrolides

Macrolides are inhibiting the growth of various bacteria in the organism and are often prescribed for the treatment of bacterial infections. These can inhibit the metabolism of Viagra. They cause elevated plasma levels, leading to a possible risk of increased side effects.

Protease inhibitors

Protease inhibitors are a class of antiviral medications that are commonly used to treat HIV/AIDS and also hepatitis C. These drugs inhibit the metabolism of Viagra, causing elevated plasma levels, leading to a possible risk of increased adverse effects. The risk of hypotension is definitely increased and everything that goes along with that.

Counter-indications and precautions

  • Nitrate must not be used in combination with Viagra. Viagra potentiates vasodilating effect of Nitric Oxide from the nitrates, which results in significant decrease in the blood pressure. The decrease may be great enough to cause death.
  • Avoid high-fat meals when taking Viagra. This is because high-fat meals decrease the absorption and cause delay the peak in extra sixty minutes. This is a long time and may cause frustration in patients.
  • If a temporary vision loss occurs, a patient is to notify his health care provider immediately. A vision loss is considered to be a serious adverse effect which may potentially lead to blindness.
  • Priapism is an erection that is lasting for a period of more than 4 hours. An erection lasting for that long a time is very uncomfortable and detrimental; besides, it may lead to the damage to the penis. In the case priapism happens, a patient is to call an emergency immediately.