The drug is recommended for men with erectile dysfunction, which is defined as the inability to achieve or maintain an erection of the penis necessary for successful sexual intercourse. For effective action of the drug, sexual arousal is necessary.
active substance: sildenafil
1 tablet contains sildenafil citrate in doses equivalent to 50 mg or 100 mg of sildenafil
excipients: calcium hydrogen phosphate dihydrate, microcrystalline cellulose, copolyvidone, colloidal silicon dioxide, talc, magnesium stearate, croscarmellose sodium, potato starch.
EROTON DOSAGE FORM
MAIN PHYSICAL AND CHEMICAL PROPERTIES:
Drugs used for erectile dysfunction. Sildenafil ATX code G04B E03.
Mechanism of action. Sildenafil is an oral drug used to treat erectile dysfunction in men. With sexual arousal, the drug restores reduced erectile function by increasing blood flow to the penis.
The physiological mechanism that leads to an erection, including the release of nitric oxide (NO) in the corpora cavernosa during sexual arousal. The released nitric oxide activates the enzyme guanylate cyclase, which stimulates an increase in the level of cyclic guanosine monophosphate (cGMP), which, in turn, causes relaxation of the smooth muscles of the corpora cavernosa, promoting blood flow.
Sildenafil is a potent and selective inhibitor of cGMP-specific phosphodiesterase 5 (PDE-5) in the corpora cavernosa, where PDE-5 is responsible for the breakdown of cGMP. The effects of sildenafil on erection are peripheral. Sildenafil does not have a direct relaxing effect on isolated human cavernous bodies, but powerfully enhances the relaxing effect of NO on this tissue. When the metabolic pathway NO / cGMP is activated, which occurs during sexual stimulation, inhibition of PDE5 by sildenafil leads to an increase in the level of cGMP in the corpora cavernosa. Thus, in order for sildenafil to cause a pharmacological effect, sexual arousal is necessary.
Absorption. Sildenafil is rapidly absorbed. The maximum plasma concentration of the drug is reached within 30-120 minutes (with a median of 60 minutes) after oral administration on an empty stomach. The average bioavailability after oral administration is 41% (with a range of values from 25 to 63%). In the recommended dose range (from 25 to 100 mg), the AUC and Cmax values of sildenafil after oral administration increase in proportion to the dose.
With the use of sildenafil with food, the degree of absorption decreases with an average lengthening of T max up to 60 minutes and an average decrease in C max by 29%.
Distribution. The average equilibrium volume of distribution (V d) is 105 liters, which indicates the distribution of the drug in the tissues of the body. After a single oral administration of sildenafil at a dose of 100 mg, the average maximum total plasma concentration of sildenafil is approximately 440 ng / ml (coefficient of variation is 40%). Since the binding of sildenafil and its main N-desmethyl metabolite to plasma proteins reaches 96%, the average maximum plasma concentration of free sildenafil reaches 18 ng / ml (38 nmol). The degree of binding to blood plasma proteins does not depend on the total concentration of sildenafil.
Excretion. The total clearance of sildenafil is 41 l / h, causing a half-life of 3-5 hours. Both after administration and after administration, the excretion of sildenafil in the form of metabolites is carried out mainly with feces (about 80% of the oral dose) and to a lesser extent with urine (approximately 13% of the oral dose).
The drug is recommended for men with erectile dysfunction, which is defined as the inability to achieve or maintain an erection of the penis necessary for successful intercourse.
For the effective action of the drug, sexual arousal is necessary.
Hypersensitivity to sildenafil or any of the excipients of the drug, simultaneous use with nitric oxide donors (such as amyl nitrite) or nitrates in any form is contraindicated, since it is known that sildenafil affects the pathways of nitric oxide / cyclic guanosine monophosphate (cGMP) metabolism and potentiates the hypotensive effect of nitrates conditions in which sexual activity is undesirable (severe cardiovascular disorders such as unstable angina or severe heart failure).
Taking the drug is contraindicated in patients who have lost vision in one eye due to non-arterial anterior ischemic neuropathy of the optic nerve, regardless of whether this pathology is associated with previous use of PDE-5 inhibitors or not.
The presence of such diseases as severe liver dysfunction, arterial hypotension (blood pressure below 90/50 mm Hg. Art.), Recent stroke or myocardial infarction and known hereditary degenerative retinal diseases such as retinitis pigmentosa retinal PDE disorders), since the safety of sildenafil has not been investigated in such patient subgroups.