International Nonproprietary Name
Sildenafil citrate
Other names used:
Revatio
Indications
Erection dysfunctions (organic, psychogenic, mixed), including those of a diabetes, adiposity, after radical prostatectomy or spinal cord traumas.
Hypersensitivity, nitrate therapy. Restrictions to application: Serious malfunctions of liver and kidneys, anatomic deformations of a sexual member, erythroid myeloma, acute leukemia, crescent-cellular anaemia, increased predisposition to bleedings, hereditary pigmentary retinitis, an aggravation of stomach ulcer and duodenal gut, heavy forms of an arterial hypertension and a hypotonia, anamnestic indications to the heart attack and stroke transferred in previous 6 months, life-menacing arrythmia, heart insufficiency, unstable stenocardia, age under 18 years old.
Collateral action
Headache, dizziness, vasodilatation (inflow), hypotension, asthenia, nasal congestion, lacrimation, malfunction of light-and colour perception, clearness of vision, dyspepsy, a diarrhoeia, nausea, abdominalgia, lumbodynia, arthralgia, myalgia , hypertonused muscles, a sleeplessness, short wind, skin rash, predisposition to infection of respiratory and urinary trackts, long painful erection (more than 4 h.).
Interaction
Strengthens orthostatic hypotension caused by nitroglycerine, anti-aggregate effects of sodium nytroprussid. Inhibitors CYÐ3À4 (cinamet, ketoconazole intraconazole, erythromycin, etc.) raise concentration in plasma, inducing substances (rifampicin, etc.) - reduce.
Overdose
Symptoms:overdose is shown by sensation of heat, dizziness, a face reddening, a headache, dysfunction of vision clearness, dyspeptic phenomena, decrease of blood pressure. Treatment: symptomatic, the dialysis is inefficient
Dosage and way of application
Inside, an hour before sexual intercourse, 50 mg. At insufficient efficiency against good shipping the dose can be increased to 100 mg.
Special instructions
Before application for diagnostics of erection malfunction, defining of its possible reasons and choosing of adequate methods of treatment, it is necessary to collect the full medical anamnesis and to fulfill careful urological and general clinical examination, especially at patients with accompanying cardiovascular diseases for which the raised sexual activity is undesirable (for example, heavy forms of ischemic heart disease and hypertensive illness). Prescribing of high doses is not recommended to elderly patients. Frequent (more than once a day) use in high doses increases risk of side-effects. Into raised risk category are included patients with accompanying ischemic heart disease as renewal of an active sexual life, including the increase in number of sexual contacts, can affect the course of the basic somatic disease or to demand correction of medicamentous therapy. The estimation of a parity advantage/risk is necessary at patients with heart insufficiency, low volume of blood circulation. To prescrive carefully to men with an arterial hypertensia ( blood pressure 170/110 mm hg) and an arterial hypotension ( blood pressure 90/50 mm hg) . Extra carefully prescribe to patients with the accompanying arterial hypertensia, under multicomponent hypotensive pharmacotherapy, cautiously - at the diseases contributing to development of priapism It is not recommended to combine with other preparations used for treatment of erection dysfunction.
Storage conditions
At temperature not above +30°Ñ in a place inaccessible to children.
Improving erectile function. Selectively inhibits cyclic guanosine monophosphate (cgmPh)-dependent phosphodiesterase type 5 (Phde5), which is contained mainly in smooth muscles of cavernous body and prevents from destruction of (cgmPh). Level increase of the latter leads to decreasing of endocellular concentration of calcium and to relaxation of smooth muscle cages of cavernous body with the subsequent increased filling of sini with blood on the background increase in an arterial blood-flow in a sexual member and squeezing of deferent veins. Strengthens and increases duration of erection, resulted after sexual stimulation. Does not influence morphology, mobility and viability of germ cells, volume and viscosity of ejaculate. Inhibits phosphodiesterase type 6 (PhDE6) of retinas (although weaker than PhDE5, action selectivity 10:1) and can cause dysfunctions of colour vision. Increases antiaggregate and de-aggregate effects of nitrogen oxydes (II) and its donors, blocks formation of thrombi ex vivo. Expands both arterial and venous vessels, causes decreasing of systolyc and diastolic blood pressure, increasing of heart rate. Provides antidiuretic action. Does not influence reproductive function, has no teratogenec, mutagen, clastogenec (chromosomal aberrations studies) and cancerogenic properties. When administered on an empty stomach is soaked up quickly and almost completely. The maximum concentration in plasma will be reached in 0,5-2 h, absolute bioavailability - 41 % (exposed to a first-pass metabolism), fat food consummation reduces intensivity of absorption to 11 %, the maximum concentration to 29 %. Substantially (96 %) binds with fibers of plasma, a half-life period - 4 h. (2-8h). It is accumulated in an organism administered 3 times a day within 9 days, cumulation makes 36 %. Up to 80 % of sildenafil metabolites are excreted with excrements and 14 % - with urine.
More about Viagra
On recently held medical round table in Paris, the French and Italian doctors have presented their research data, in pursuant of 85% of patients who were taken Viagra, declare that they felt a deep satisfaction, only 9% consider this drug insufficiently effective, and only 2% decided to not take Viagra anymore, for fear of the side effects.
