Viagra Sildenafil Interesting Facts

Viagra - a reliable drug for treating erectile dysfunction. He does not act by itself,
and assists in the presence of natural desire and inclination to commit the sexual act.
The drug is a potent and selective inhibitor of cGMP-specific phosphodiesterase type 5 (PDE5).
The physiological mechanism of erection involves release of nitric oxide (NO) in the cavernous body during sexual stimulation. Nitric oxide activates the enzyme guanylate cyclase, which leads to increased
cyclic guanosine monophosphate (cGMP), relaxation of smooth muscle and corpus cavernosum
increased blood flow to the penis.
Viagra has no direct relaxing effect on isolated human corpus cavernosum,
but also actively enhances the relaxing effect of NO on this tissue by inhibiting PDE5,
which is responsible for the breakdown of cGMP in the cavernous body.
When sexually aroused, the local release of NO under the influence of sildenafil results
to PDE5 inhibition and increase cGMP in the cavernous body, resulting in
relaxation of smooth muscles and increasing blood flow in the cavernous body.
The use of Viagra at recommended doses, is ineffective in the absence of sexual stimulation.
Studies in vitro showed a high selective effect of sildenafil on PDE5.
The activity of sildenafil against PDE5 than its activity against other known
isoforms of phosphodiesterase (10 times - FDE6, more than 80 times - FDE1, more than 700 times - FDE2,
FDE3 and FDE4, FDE7 - FDE11). Thus possible to avoid negative side effects.
Regarding PDE5 Viagra is approximately 4000 times more active than in respect
FDE3 - cAMP-specific phosphodiesterase involved in the regulation of contractions of the heart,
makes the risks of negative impacts of the drug on heart action almost nil.
On the other hand due to the low selectivity against FDE6 some patients
1 h after taking Viagra in doses of 100 mg showed slight and reversible disruption of distinction
color (blue / green) with the test Farnsworth-Munsell 100;
2 hours after taking the drug, these changes disappeared.
Violations of established mechanisms of color vision is oppression FDE6,
which is involved in the transmission of light in the retina.
Studies in vitro have shown that the effect of sildenafil on FDE6 just 10 times inferior to its activity
against PDE5.
Viagra has no effect on visual acuity, sensitivity to contrast, elektroretinogrammy,
intraocular pressure or pupil diameter.
Sildenafil at a dose of 100 mg had no effect on locomotor activity or morphology of sperm in their single dose in healthy volunteers.
These clinical
Acute administration of Viagra in doses up to 100 mg did not cause clinically significant changes in ECG
in healthy volunteers.
The maximum decrease in systolic blood pressure in the prone position in the application of the drug inside
a dose of 100 mg was on average 8.4 mmHg The corresponding decrease in diastolic blood pressure
in the prone position was 5.5 mm Hg
More marked, but similarly transient effect on blood pressure was observed in patients
simultaneously treated with nitrates.
In studies the impact of single dose of sildenafil 100 mg on hemodynamics
in 14 patients with severe coronary artery disease
(stenosis> 70% at least one coronary artery) averages
reduction in systolic and diastolic blood pressure were respectively 7% and 6% on
normal level. Systolic pressure in the pulmonary artery was reduced by an average of 9%.
Viagra did not influence cardiac output and will not compromise the blood flow through stenosed
coronary artery, which resulted from the improvement (13% approximately) reserve
adenosine-induced coronary blood flow (as in the stenosed and
in intact arteries).
Efficacy and safety of sildenafil was studied in 21 randomized, double-blind,
placebo-controlled study lasting up to six months. Viagra used
more than 3000 patients with erectile disorders of various etiologies (organic,
psychogenic, mixed) aged 19 to 87 years.
Effectiveness was determined on the basis of overall assessment, diaries, recording an erection,
evaluation of the international index of erectile function (IIEF, a questionnaire designed to assess sexual function), and survey partners.
The effectiveness of sildenafil, which was estimated by the ability to provide advance preparation and conservation of an erection sufficient for sexual intercourse, was demonstrated in all 21 studies and was maintained during long-term treatment (1 year). If you are using Viagra in a fixed-dose proportion of patients reported improvement in erectile function, was 62% (25 mg), 74% (50 mg) and 82% (100 mg), while placebo - 25%. In addition to improving erectile function, IIEF analysis showed that treatment with Viagra improves as orgasm, satisfaction with sexual intercourse and overall satisfaction.
In all studies, the proportion of patients with diabetes, indicating improvement in the treatment of
Viagra, accounted for 59% of patients after radical prostatectomy - 43% of patients
with spinal cord injury - 83% (versus 16%, 15% and 12% of patients receiving placebo,
respectively).

Pharmacokinetics

The pharmacokinetics of sildenafil is dose-dependent when administered in the recommended dose range.
The elimination of the drug occurs mainly through hepatic metabolism (mainly the isoenzymes of cytochrome P450 3A4) with the formation of the active metabolite, on properties similar to sildenafil.
Suction
After receiving the drug inside sildenafil is rapidly absorbed. Absolute bioavailability averages 41% (25-63%). After receiving the drug inside the fasting Cmax is reached within 30-120 min (average 60 minutes).
When you receive Viagra in combination with fatty food reduces the rate of absorption, Tmax is increased by 60 min, and Cmax decreased by an average of 29%.
Distribution
Vd sildenafil at steady state an average of 105 liters, indicating that its distribution in the tissue.
Sildenafil and its major circulating N-desmetilovy metabolite approximately 96% bound to plasma proteins.
Protein binding is not dependent on the total concentration of sildenafil.
In healthy volunteers who received Viagra (single dose of 100 mg), less than 0.0002% (average 188 ng) dose was found in semen after 90 min after administration.
Metabolism
Sildenafil is metabolized, primarily by CYP 3A4 (major route) and CYP 2C9 (non-substantive way) microsomal isoenzymes of the liver. Sildenafil is a weak inhibitor of isoenzymes of cytochrome P450 - 1A2, 2C9, 2C19, 2D6, 2E1 and 3A4 (IK50 <150 mmol). In applying Sildenafil at recommended doses, it is unlikely that sildenafil is able to influence the clearance of substrates of these isoenzymes.
The main circulating metabolite, which is formed by the N-desmetilirovaniya Sildenafil undergoes further metabolism.
On the selectivity of action on PDE metabolite comparable with sildenafil, and its activity against PDE5 in vitro is about 50% of the activity of sildenafil.
Concentration of metabolite in plasma is approximately 40% from those of sildenafil.
N-desmetilmetabolit undergoes further metabolism, and its terminal T1 / 2 is about 4 hours
Withdrawal
Total clearance of Viagra from the body is equal to 41 l / h, T1 / 2 in the terminal phase - 3-5 hours after ingestion or in / to the introduction of sildenafil is excreted as metabolites primarily in the faeces (approximately 80% of the dose introduced into) and to a lesser extent in the urine (about 13% of the administered oral dose).
Pharmacokinetics in special clinical cases
The increase in the level of sildenafil in plasma (AUC) influence the following factors: age over 65 years (an increase of AUC by 40%), inadequate liver function (eg, liver cirrhosis, 84%), severe renal insufficiency (CC <30 ml / min , 100%), concomitant administration of drugs - inhibitors of cytochrome P450 3A4 (eg, erythromycin, 182%, saquinavir, 210%).
In healthy elderly (65 years and older) volunteers sildenafil clearance was reduced, and the concentration of free active substance in the plasma by approximately 40% higher than its concentration in healthy young (18-45 years) volunteers.
In volunteers with mild (CC 50-80 ml / min) and moderate (CC 30-49 ml / min) renal insufficiency pharmacokinetic parameters of sildenafil after oral single dose (50 mg) did not change.
In volunteers with severe renal insufficiency (QA <= 30 ml / min) decreased clearance of sildenafil, which resulted in approximately a twofold increase in AUC (100%) and Cmax (88%) compared with those of volunteers, matched for age, who had no renal impairment.
In volunteers with mild to moderate hepatic cirrhosis (Child-Pugh A and B) sildenafil clearance is decreased, which led to an increase in AUC (84%) and Cmax (47%) compared with those of volunteers with normal liver function, matched by age.

Indications

- Erectile dysfunction, characterized by the inability to achieve or maintain penile erection sufficient for sexual intercourse.
The drug Viagra is effective only when there is sexual stimulation.

Dosage regimen

The drug is taken orally.
For most patients the recommended dose is 50 mg; take medication if necessary for about 1 hour before sexual activity. Given the efficacy and tolerability the dose may be increased to 100 mg or decreased to 25 mg.
The maximum recommended frequency of application - 1 times / day.
In applying the drug in patients aged over 65 years, patients with impaired hepatic function, patients with severe renal insufficiency and in patients receiving both drugs - inhibitors of cytochrome P450 3A4 (eg, erythromycin, saquinavir), there is an increase in plasma levels of Sildenafil that may contribute to increase the effectiveness of the drug, and the possible appearance of side effects. Can expect that even more powerful inhibitors of cytochrome P450 3A4 such as ketoconazole or itraconazole may lead to increased levels of sildenafil in plasma. Should discuss whether the use of the drug in a dose of 25 mg / day for similar groups of patients.
The product is not intended for use in patients under the age of 18 years.

Side effects

Side effects are more common than 5% of patients taking sildenafil as needed, are given in the table.



Side effects in reported incidents of adverse effects (%)
Viagra (n = 734) Placebo (n = 725)
Headache * 16% 4%
Tides * 10% 1%
Dyspepsia * 7% 2%


* - A side effect reported in clinical studies.
In clinical studies, II / III phase with the selection of doses for patients treated with sildenafil as needed, there were between 1% and 5% following a clinically significant side effects, as well as those phenomena whose relationship with the drug intake was possible:
On the part of the organism as a whole: asthenia, pain, abdominal pain, back pain, infection, flu-like syndrome.
From the cardiovascular system: vasodilation (side effect reported in clinical studies).
From the digestive system: diarrhea, nausea.
The part of the musculoskeletal system: joint pain, muscle pain.
From the central nervous system and peripheral nervous system: dizziness (side effect reported in clinical studies), increased muscle tone, insomnia.
On the part of the respiratory system: nasal congestion, pharyngitis, rhinitis (side effect reported in clinical studies), sinusitis, respiratory infections, respiratory dysfunction.
Dermatological reactions: rash.
From the senses: vision changes (mild and transient, mostly change the color of objects, as well as increased perception of light and blurred vision - a side effect reported in clinical studies), conjunctivitis.
The part of the urinary system: urinary tract infections.
On the part of the reproductive system: dysfunction of the prostate.
Using Viagra in doses greater than recommended, the side effects were similar to the above, but usually more often.
The following adverse events were recorded during postmarketing use.
Since the cardiovascular system: hypotension, syncope, tachycardia, palpitations.
From the digestive system: vomiting (side effect reported in clinical studies).
On the part of the reproductive system: prolonged erection and / or priapism.
From the sense organs: eye pain, redness of eyes.
Other: allergic reactions.
Side effects were usually transient and light to moderate.
In studies with fixed dose rate of side effects increased with increasing dose.
The nature of side effects in studies where doses were selected, since such studies better reflect the recommended scheme of application, was comparable to that in studies with fixed doses.
Contraindications

- Hypersensitivity to the ingredients.
Viagra contraindicated in patients treated continuously or intermittently donator of nitric oxide, organic nitrates or nitrates in any form, as sildenafil enhances the hypotensive effect of nitrates, taken continuously or in an emergency.

Pregnancy and lactation

The product is not intended for use in women.
There are no adequate and strictly controlled trials in pregnancy and lactation in women took place.
Results of experimental studies
Reproduction studies in rats and rabbits, oral use of sildenafil did not exert teratogenic effects, had no effect on reproductive function and did not cause any violation of the peri / postnatal development.

Cautions

For the diagnosis of erectile dysfunction, determine their possible causes and select appropriate treatment is necessary to collect a complete medical history and thorough physical examination.
Sexual activity is a risk for heart disease, in this regard before any therapy at the violations of erection doctor may deem it necessary to study the cardiovascular system.
In clinical trials Viagra has systemic vasodilating effect, which leads to a transient reduction of blood pressure. This effect has little value or no leads to any consequences in most patients. However, until the appointment of sildenafil physician must carefully weigh the risk of undesirable manifestations vasodilating action in patients with certain concomitant diseases, especially against the background of sexual activity. Increased sensitivity to the vasodilator observed in patients with obstruction of left ventricular output tract (eg aortic stenosis, hypertrophic cardiomyopathy), as well as the rare atrophy in multiple different systems, manifested severe violation of autonomic control of blood pressure.
Preparations intended for the treatment of erectile dysfunction, should be used with caution in patients with anatomical deformation of the penis (eg, angulation, cavernous fibrosis or Peyronie's disease) and patients with diseases that predispose to the development of priapism (such as sickle cell anemia, multiple myeloma, or leukemia).
Preparations intended for the treatment of erectile dysfunction, should not be given to men for whom sexual activity is undesirable.
Safety and effectiveness of Viagra when used in combination with other tools designed for the treatment of erectile dysfunction, were not studied, so the use of such combinations is not recommended.
Studies of human platelets in vitro suggest that Viagra increases antiagregantny effect of sodium nitroprusside (nitric oxide donator).
No information about the safety of Sildenafil in patients with diseases which are accompanied by bleeding, or exacerbation of peptic ulcer, no, so in these patients the drug should be used with caution.
A small number of patients with hereditary retinitis pigmentosa are inherited disorders of phosphodiesterases in the retina. No information about the safety of sildenafil in patients with retinitis pigmentosa is not, in this regard such patients sildenafil should be used with caution.
Use in Pediatrics
Sildenafil is not intended for use in children and adolescents under the age of 18 years.
Results of experimental studies
There was no evidence of carcinogenicity of the drug as a 24-month study in rats at doses 42 times the maximum recommended dose for humans (MRD), calculated per kilogram of body weight (and approximately 5 times the MRD, as calculated in mg/m2 of body surface ) and at 18-21-month study in mice at doses 5 times the MRD, calculated in mg / kg body weight (and approximately 2 times the MRD in mg/m2 of body surface).
Bacterial and in vivo tests to study the mutagenicity were negative.

Phentermine At UsRxMed.com It's Real New! News From Our Guide

Name: phentermine - 2-methyl-1-phenylpropan-2-amine and 2-methyl-amphetamine.

Synonyms: duromin, ionamin, durominc, adipex.

Classification by action: psychostimulant.

Dosage: 100 mg - oral (mouth).

Phentermine - phenethylamine, sympathomimetic drug substance, a derivative of amphetamine, primarily used to suppress appetite. Phentermine suppresses appetite by acting on the central nervous system similar to amphetamine. Typically prescribed to people suffering from overweight, instead of surgical methods. Phentermine is implemented as a fast form (adipex) and in the form of resins with prolonged action (ionamin, duromine in Australia and New Zealand).

Known, only one prospective randomized controlled trial, which lasted more than 6 months, which assessed the effectiveness of phentermine for weight loss. In this study, published in 1968, involved 108 women with obesity treatment which consisted of a low-calorie diet (1000 kcal / day) and a daily administration of phentermine, and placebo (dummy) with alternation of a month, or only placebo for 36 weeks. 64 patients who participated in the study reduced their weight by 13% from the original.
According to official statistics, in 1998, British doctors were issued about 20 000 prescriptions for this drug. However, some estimate the real consumption of Phentermine has been much higher, since not less than 100 000 British women took the drug. Currently, the UK market were only 2 drugs for those wishing to lose weight with pills - methyl cellulose and orlistat.

What Is Tramadol - News From Our Guide

There is hardly a person who does not know the feeling of pain. The ancient Greeks said: «pain - is the watchdog of health». Indeed, it is the pain body warns of impending danger.

Today the pharmaceutical market represented a lot of pain medication foreign and domestic production. Among them - Tramadol, publication of which has recently mastered Kharkiv JSC «Pharmaceutical Firm« health ».

Produced by that enterprise Tramadol produced by domestic technology using imported substances (tramadol hydrochloride) company «Heumann Pharma Gmbh» (Austria).

Tramadol - a highly non-narcotic centrally acting analgesic, intended for oral administration in acute or chronic pain of various etiologies. Tramadol belongs to a class of moderately toxic, has a good tolerance.

As an agonist-antagonist of opioid receptors, the drug has a marked analgesic activity. Its action occurs within 20 min after administration and lasts up to 5 hours

The product effectively eliminates Moderate pain in the postoperative period, with injuries, bilious colic, myocardial infarction, during a painful diagnostic procedures. In addition, tramadol has antibechic action.

When receiving therapeutic doses of Tramadol does not cause respiratory depression and has no effect on motor function of the intestine.
The drug is produced in gelatin capsules to 0,05 g Adults and children over 14 years of medication prescribed 1 capsule with a small amount of liquid.
During treatment with Tramadol should observe certain precautions: to abandon the car and driving performance of potentially hazardous activities requiring increased attention and speed of mental and motor responses.

Patients with abnormal liver function or renal drug treatment should begin with minimal doses. Particular caution while taking Tramadol should be exercised when administering it to patients with drug and alcohol addiction.

More than 20 years of clinical experience with drugs tramadol overseas and in hospitals of Ukraine testifies under preparation contemporary requirements for effective and safe drug to eliminate pain.

New Way RX Way

Physical activity, proper nutrition, not smoking and excessive intake of alcohol, associated with obesity are important therapeutic factors in patients with erectile dysfunction. However, in many cases this is not enough and have to resort to the use of different treatment methods.

Psychotherapy and / or behavioral therapy as a self-treatment can be effective in the absence of organic causes of ED, as well as psychological factors are very important in all forms of ED. Proper study of the psychological and psychosexual attempt to alleviate the anxiety of the patient should be a mandatory part of the therapeutic effects of this pathology.

Vacuum devices help many patients, but from an aesthetic point of view of suit only a small number of patients.

Surgical treatment in the form of operations on the vessels of the penis is very popular in the past, now rarely used due to its low long-term effectiveness. However, in young patients with pelvic and perineal trauma surgical repair of vascular permeability of the penis in some cases gives good results.

Installing the prosthesis into the penis in almost all cases leads to complete recovery of patients, but now resorting to this method only if the ineffectiveness of all other therapeutic methods.

The method of introducing into the penis of medicinal preparations, despite the fairly high efficiency, has certain drawbacks, the most important of which is the need for painful injections into the penis and the presence of complications such as priapism (painful prolonged erection).
Revolutionary event in the treatment of erectile dysfunction was the appearance in 1996, the drug sildenafil citrate, has become known under the trade name "Viagra". This drug, taken orally in a tablet form, increased the effectiveness of treatment and provided an opportunity for general practitioners to help patients with ED. However, many men, especially with severe erectile dysfunction, diabetes, arterial hypertension, and patients who had undergone radical prostatectomy, is not fully satisfied with the existing treatment. In addition, the effect of sildenafil depends on eating and drinking, often victims of sexual components, which creates some problems with the planning of sexual intercourse. These circumstances lead to the fact that on average only 50% of patients taking sildenafil, intend to continue treatment.

27 Medical Categories

We would also like to say a few words about our categories, and they we had accumulated 27! Very important role we assigned the category of Erectile Dysfunction, well then I think goes without saying. But here is some can be attributed, and Male Enhancement is also not unimportant group. By popular demand, we have included Anti-Acidity medications. It will be interesting to many. Anti-Allergic/Asthma is very popular category for many millions of people around the world, because there are products that can really help with serious illness and disease. Anti-Depressant Anti-Anxiety is active for both men and women. This is a unique group of products includes a large list. Very important category as it turned out that Anti-Diabetic just been added at the request of buyers. Well, we are always happy. Anti-Fungus worthy of respect, a short and simple section with the necessary descriptions of the various classes of medicines. But the Anti-Herpes is already a rare category we nevertheless felt it necessary and implement. Quite a large and perhaps one of the most important Antibiotics undisputed leader among the other categories. But it can compete medicine from Blood Pressure / Cholesterol category, which also includes a long list of pills. Exotic at the same time highly questioned category Body-Building has not been forgotten by us, too. Well, what about your teeth? Oh yes We remember about them. Therefore added Dental Whitening for certain individuals. Continuing the theme of men's health would like to tell men not to forget about the group Erection Packs simple and affordable solution formulated on the basis of established medicine. We love women - that have made the decision for them in the form of Female Enhancement Group. Try it! So went a little farther from the main theme would say about the main section of the largest that we have a General Health that fits in a more than 70 drugs! Yes it is stunningly large category. We use Gums New is for those who love them, their little but still better than nothing - a little variety. Healthy Bones includes the world-famous products, naturally with the description. Now some exclusives - we use Hypnotherapy group with 4 products from our sponsors, I think you'll love them! The next 2 groups is also important for us like men again complete the category Men's Health, and for many of the most demanded Pain Relief (including the famous produtky). There is a good solution for different Patches New because everything is simply and clearly itemized. Wait! And you know that we did not forget about the animals? Yes we are! We love all! Include your pets. I added the category Pets. Use it wisely and you will be happy! Skin Care is particularly well should be in demand in the summer because it is seasonal products for the majority. We are mindful of the problems and insomnia for all ages as a result Sleeping Aid is always at your service. Exactly as in the latter category Stop Smoking section is very necessary and will always be relevant because the problem of smoking in the world badly solved, there are many options but we offer the best. How could we forget about Weight Loss? No! We have not forgotten of course! This is a group member of the 5 most desired. And also to love our women, we have added a full chapter to them - Women's Health with a large assortment of goods, now we can guarantee you a healthy life with usrxmed.com you are not only able to save your money well and always be aware of all the world events in the world of health .

We Done

Well, that happened! We completely finished the update of our service, it is now a full-fledged online pharmacy guide where you can find absolutely free information about medicines, tablets, pills and health products and buy them on the sites of our advertisers. We made as simple and convenient service for you. You might want to visit all products page and choose what you need. We also reviewed the latest global health news as well as added a medical blog, which will be located the information about our company and about what we do and discuss any issues arising from the service and of course information about medications, diseases, treatment and prevention and many other very useful to all. We offer a highly efficient medical service, but we do not provide medical services - it is important to understand. We are one of those who believe in a healthy future for people on the planet! In order for you to orient it easier to use our sitemap it will help you find the necessary links

Soon change!

Hey all! We are glad to see you again on this blog is not official. We would just mention the main news, our developers completing a partial change of design as well as the massive addition of content, it includes about 25-27 parts of (currently), such as: Erectile Dysfunction, Male Enhancement, Anti-Acidity, Anti - Allergic / Asthma, Anti-Depressant/Anti-Anxiety, Anti-Diabetic, Anti-Fungus, Anti-Herpes, Antibiotics, Blood Pressure / Cholesterol, Body-Building, Dental Whitening, Erection packs, Female Enhancement, General Health, Gums New, Healthy Bones, Hypnotherapy, Men's Health, Pain Relief, Patches New, Pets, Skin Care, Sleeping Aid, Stop Smoking, Weight Loss, and Women's Health. These sections will generally be the order of 650-700 tablets, medicines and all kinds of medical products. But we also wanted to say that the list may be updated from time to time, and in the future, you can find almost any product. We encourage you to remember the url of our pharmacy guide. You can trust us - we do our job well and professionally! If you now wish to visit our site, you can see is only the older version, but do not be upset, we do everything possible to expedite the process.