Revatio (sildenafil) makes the muscles more relaxed and arouses the blood to flow into specific areas of your body.
Patients take Revatio as a medicine that doctors prescribe for treating PAH (pulmonary arterial hypertension). Blood pressure in lungs increases when a person has PAH. The action of the heart has to be fast and active so that the blood goes right to the area of lungs. Your physical condition becomes better and the declining changes will reduce after using this medicine. You can do exercises and the symptoms of disease will be minimal.
PDE-5 enzyme called phosphodiesterase is getting blocked when using Revatio. This type of enzyme answers for splitting chemical solutions that relax blood vessels in your lungs. These chemical solutions become more available when Revatio blocks PDE-5 enzymes. The blood flows more easy through blood vessels in the lungs when they are relaxed.
Usually pulmonary arterial hypertension has symptoms when people can not participate in physical activities or perform some exercises. Revatio can help you to decrease these inabilities and help you to normally exercise. The worsening conditions can be reduced. This will help to avoid such outcomes like necessity of another drugs, transplantation of lungs or sometimes death.
They didn't develop a cure for PAH yet. When you know the cause of disease, they find a treatment that is intended for this cause. Besides, this treatment can make less the symptoms of disease.
The below listed treatment can improve some symptoms you have:
Warfarin or another blood thinning drug that prevents from clot of blood
Physical exercises that make your forbearance better
Other medicines are expanding or widening pulmonary arteries which help your heart to easier pump blood through these arteries. This is the type of treatment that Revatio uses. In the following list, there are drugs that apply the same mechanism of treatment:
Revatio is recommended to take TID in 20 mg pills. A patient can take the pill during nourishing or not and the space time between intakes could be four or six hours.
The researches showed that it will not be effective if the dose will be increased. It is forbidden to use a treatment when pills are taken three times a day and they are more than 20mg. A dose of less than 20mg three times a day was not researched. So, we still don't know if this kind of dose is effective.
Patients that are under continued treatment of PAH could use Revatio injection if they can not take oral Revatio at the moment.
For Revatio injection it is recommended to take a dose of 10mg or 12.5mL that is intended for intravenous push injection TID. It is possible of not to adjust the dose of injection of Revatio to the body weight you have.
It is predicted that a Revatio injection dose of 10 mg has the same amount of Viagra and its metabolite of N-desmethyl as it is consists in a 20mg pill of Revatio.
Also, your healthcare provider needs to be informed if you are using drugs to cure ED, any vitamins, medicine that is sold over the counter or by prescription, herbal supplements or nitrates.
Important warnings and precautions
When people took this medicine, it was reported about serious conditions that happened to them as side effects. The were, bleeding in lungs or brain, seizure or stroke. Some people died suddenly when they took sildenafil citrate as a medicine against ED. Revatio's active ingredient is sildenafil citrate. These side effects could happen more possible if the person has significant risk factors of heart sickness or has a cardiovascular disease or as it is also called disease of blood vessels.
The medicine may develop hypotension to patients that take Revatio. Dizziness and faintness may be a result of low blood pressure. So, if you begin to feel this condition, during treatment with Revatio, you should lie on a bed. This feeling can be reduced if you be careful and make your moves more slow when you want to sit down or stand up. Try to lean on something when you are doing these movements.
NAION or nonarteritic anterior ischemic optic neuropathy comes to people that take Revatio or other types of PDE5 inhibitors. The consequence of such state can be loss of sight for both or one eye. But this condition could last for a small period of time. If you see that Revatio makes harm to your vision, you should immediately go to your doctor.
Patients that took Revatio or some other PDE5 inhibitors had also experienced loss of hearing. It had always been accompanied by singing in ears or dizziness. Once you feel that you experience these conditions, you should visit a doctor by all means.
A serious condition called priapism happens to those that take PDE5 inhibitors or phosphodiesterase type-5 inhibitors like Revatio. This condition is an erection that is very painful and lasts for a long time. When you see that the erection doesn't leave you, after 4 hours, you should talk to the doctor immediately. If you don't do first medical aid, you might damage your penis or have impotence.
Revatio is available in generic form as sildenafil citrate. This ingredient is also sold as Viagra that people use to cure impotence. So, it is advised not to take Revatio with another inhibitors of PDE5, like Levitra, Viagra or Cialis.
They consider Revatio as a medicine that belongs to the Category B pregnancy medication. So, perhaps you can use this medication when you are pregnant, but unfortunately the total risk is unknown. Penetration of Revatio into breast milk is unknown. It means that if a patient is feeding with her breast or is planning to do it, she should consult with her doctor about the damage of this drug.
It is forbidden to use Revatio for those, that:
Have allergies to inactive components that they use to produce this medicine, or if they have allergies on sildenafil citrate, Revatio or Viagra
You could have headache, bleeding of nose, giddiness, precollaptoid state, burn in heart, insomnia, flushing or your ankles, hands and feet can swell. A person could have problems with vision, be sensitive to light, and mix such colors like green and blue. Notify your pharmacist if you noticed that these conditions are persisting.
Try to slow your moves when you are getting up or rising from a bed or a chair, it will decrease giddiness and dizziness. You should understand that your healthcare provider made this prescription to you, because he assumed that you will have less side effects with this medicine and the treatment will bring benefits. That is why some people do not experience side effects.
It happens very rare, when patients experience sightlessness on both or one eye, or they have NAION. Sildenafil could even not be a reason of this condition. Nevertheless, you should interrupt using sildenafil and go to the emergency room. If a person is diabetic, has problems with heart, he has high level of cholesterol, high pressure of blood, your age is more than 50 and you are a smoker, or you have eye disease, he has a greater possibility to have such problems with eyesight.
You should reduce your sexual activity, because it may be dangerous to your heart. If a person has a week heart, and while having sex, he nauseate, faints, feels pain in jaw, chest or in left arm, he should immediately stop using saldenafil and visit a doctor.
One of the dangerous side effects may occur when a person has a prolonged erection that could last for more than 4 hours. He also needs to cancel his treatment with saldenafil and get medical help, unless he will have huge long lasting problems. A rare fact, when people experienced problems with their ears, like deafness or ringing in both or one ear. This condition also requires stopping the treatment and a visit to a doctor.
There were not so many cases when people experienced a hard allergy. Still, if you see that your tongue, face or throat is swollen and your skin itches, you have a rash, troubles when you breath or hard dizziness, you need to go to a doctor.
We may not listed all the side effects that could occur to people that are using this drug. When you felt one of the above listed side effects, you need to go to a pharmacist or your doctor.
Sildenafil's action is to inhibit type-5 phosphodiesterase in the pulmonary vasculature's smooth muscle. PDE5 degrades cGMP. It also relaxes smooth muscle of pulmonary vasculature by increasing cGMP. If you have a pulmonary hypertension, you might vasodilate your bed of pulmonary vasculature and make low in systemic circulation your vasodilatation.
Testings in laboratory conditions had demonstrated that this ingredient is culling to PDE5. It better effects PDE5 than other phosphodiesterases that are known. (10-fold for PDE6 is higher than 80-fold for PDE1 which is more that 700-fold that is for PDE2, PDE3, PDE4, PDE7, PDE8, PDE9, PDE10 AND PDE11) The selectivity of 4,000-fold is more selective for PDE5 comparing to PDE3. It is very significant because it takes part in controlling cardiac contractility. Sildenafil has a 10-fold for PDE5's potent comparing to PDE6. It is an enzyme that consists in retina and takes part in its phototransduction pathway. This low culling is the reason why people have problems with differing the colors, because of the levels of plasma and bigger doses.
PDE5 also consists in tissues of platelets, visceral and vascular smooth muscle, thereto the corpus cavernosum and smooth muscle of pulmonary vessel. During laboratory tests it was observed that PDE5 inhibits these tissues with sildenafil and makes it the reason of increased anti-aggregatory activity of nitric oxide. It also makes the dilatation of acentric veins and arteries mild.
Pfizer Inc. is the company that produces Revatio. They still have rights for manufacturing the medicine and the generic competition is excluded.
In September, 2012, the patent for Revatio is expiring. Firstly, this patent was due March 2012, but they got an extension because they made pediatric studied with this drug that were highly needed.
The extension or shortening of this period could happen under certain circumstances. For example, if they find another way to use Revatio or a lawsuit that forbids producing it. There are a lot of companies that can produce a generic version of Revatio, when the expiring date of the patent comes.
Is Sildenafil Citrate a generic form of Revatio?
It is false. Sildenafil citrate is just the main ingredient in the content of Revatio. Sometimes it is confused when people call the active ingredient as the generic version of the medicine.
The original drug has to have an expired patent in order to produce the generic version of it. Also a different company has to make the generic version, but not the manufacturer of the original product.
The interactions are possible if Revatio is taken in the same time with the other drugs. Nitrates lead to negative reaction as well as alpha blockers if to take it together with Revatio. Medicine, which influence blood pressure makes negative reaction with Revatio too. Many medications may be altered by such interections in blood, so that considerable complications may occur. It is important to inform the healthcare provider which medications you take.
Potentially, Revatio (sildenafil citrate) may interact with numerous other drugs. Interactions may be evoked by the drugs which contain the next list of elements (list is not limited):
Nitroglycerin tablets or capsules (Nitro-Time, Nitrostat)
Combination of Revatio and an alpha blockers may be the cause of hypotension, in other words, low blood pressure. In such case you may feel dizziness, fainting and even lightheadedness. To reduce these symptoms and risk of hypotension you have to separate the doses of medications you take. As well it is necessary to monitor the blood pressure regularly if you take Revatio with alpha blockers.
Blood pressure drugs
Blood pressure drugs in combination with Revatio may effect too considerable decrease of your blood pressure. It is necessary to monitor the blood pressure more closely if you take blood pressure drugs together with Revatio.
CYP 3A4 inducer drugs
Enzymes, which are called CYP 3A4 enzymes, help your body to break down Revatio. Liver contains given enzymes. These enzymes' activity may be increased by the other medications. They are CYP 3A4 inducers. If you combine CYP 3A4 inducers and Revatio, the level of the last one in your body may become lower. That may lead to decrease of Revatio effectiveness. If you need to take CYP 3A4 inducer together with Revatio, it is necessary to increase dose of Revatio.
CYP 3A4 inhibitor drugs
Enzymes, which are called CYP 3A4 enzymes, help your body to break down Revatio. Liver contains given enzymes. These enzymes' activity may be decreased by the other medications. They are CYP 3A4 inhibitors. If you combine CYP 3A4 inhibitors and Revatio, the level of the last one in your body may become higher. That may lead to increase of side effects. If you need to take CYP 3A4 inhibitor together with Revatio, it is necessary to decrease dose of Revatio.
Other PDE5 inhibitors
Revatio refers to the group of PDE5 inhibitors that is why it is not recommended to use it with some other PDE5 inhibitor. If you do it, the risk of considerable side effects will be increased. For erectile dysfunction sometimes PDE5 inhibitors are used. You have to talk to healthcare provider if you are going to take Revatio together with drugs for erectile dysfunction.
If you use sapropterin together with Revatio, it may lead to considerable decrease of blood pressure. It is necessary to monitor patient's blood pressure more often if he/she takes these two medication simultaneously.
It is prohibited to take nitrate medications with Revatio. If you do it, your blood pressure may become so much lower that it may be unsafe. Even if you take a nitrate very rarely, you are prohibited to use Revatio, as to predict the time when you need to use nitrate is impossible.
Probably, not all interactions of medicine with Revatio were described in this article. For that reason, you have to talk with your healthcare provider or pharmacist about any definite interactions which may relate to you.