Sildenafil Citrate

Viagra tablets 0.1g

Release form, composition and packaging

Tablets coated with a blue film, diamond-shaped, slightly biconvex, with cut and rounded edges, with the engraving "Pfizer" on one side and "VGR 25" on the other.

  • 1 tab.
  • sildenafil citrate | 35.112 mg, |
  • which corresponds to the content of sildenafil | 25 mg |

microcrystalline cellulose - 78.291 mg, calcium hydrophosphate - 26.097 mg, sodium croscarmellose - 7.5 mg, magnesium stearate - 3 mg.

The composition of the film shell*: opadray blue OY-LS-20921 (hypromellose, lactose, triacetin, titanium dioxide (E171), aluminum varnish based on indigocarmine (E132)) - 3.75 mg and opadray transparent YS-2-19114- A (hypromellose, triacetin) - 1.125 mg.

1 pc. - blisters (1) - cardboard packs with the control of the first opening.

Tablets coated with a blue film, diamond-shaped, slightly biconvex, with cut and rounded edges, with the engraving "Pfizer" on one side and "VGR 50" on the other.

  • 1 tab.
  • sildenafil citrate | 70.225 mg, |
  • what corresponds to the content of sildenafil | 50 mg |

microcrystalline cellulose - 156.581 mg, calcium hydrophosphate - 52.194 mg, sodium croscarmellose - 15 mg, magnesium stearate - 6 mg.

The composition of the film shell*: opadray blue OY-LS-20921 (hypromellose, lactose, triacetin, titanium dioxide (E171), aluminum varnish based on indigocarmine (E132)) - 7.5 mg and opadray transparent YS-2-19114- A (hypromellose, triacetin) - 2.25 mg.

  • 1 pc. - blisters (1, 2) - cardboard packs with the control of the first opening.
  • 2 pcs. - blisters (1, 2) - cardboard packs with the control of the first opening.
  • 4 pcs. - blisters (1, 3) - cardboard packs with the control of the first opening.
  • 12 pcs. - blisters (1) - cardboard packs with the control of the first opening.

Tablets coated with a blue film, diamond-shaped, slightly biconvex, with cut and rounded edges, with the engraving "Pfizer" on one side and "VGR 100" on the other.

  • 1 tab.
  • sildenafil citrate | 140.45 mg, |
  • which corresponds to the content of sildenafil | 100 mg |
  • microcrystalline cellulose - 313.162 mg, calcium hydrophosphate - 104.388 mg, croscarmellose sodium - 30 mg, magnesium stearate - 12 mg.

The composition of the film shell*: opadray blue OY-LS-20921 (hypromellose, lactose, triacetin, titanium dioxide (E171), aluminum varnish based on indigocarmine (E132)) - 15 mg and opadray transparent YS-2-19114- A (hypromellose, triacetin) - 4.5 mg.

1 pc. - blisters (1, 2) - cardboard packs with the control of the first opening.
2 pcs. - blisters (1, 2) - cardboard packs with the control of the first opening.
4 pcs. - blisters (1) - cardboard packs with the control of the first opening.

* up to 30 micrograms/g of vanillin and/or biotin can be added to the blue film coating; the content of one or both components in the film coating will be up to 0.75 micrograms, 1.5 micrograms and 3 micrograms for dosages of 25 mg, 50 mg and 100 mg, respectively.

Pharmacological action

Sildenafil is a potent selective inhibitor of cGMP-specific phosphodiesterase type 5 (PDE5).

The realization of the physiological mechanism of erection is associated with the release of nitric oxide (NO) in the cavernous body during sexual stimulation. This, in turn, leads to an increase in the level of cGMP, subsequent relaxation of the smooth muscle tissue of the cavernous body and an increase in blood flow.

Sildenafil does not have a direct relaxing effect on the isolated cavernous body in humans, but enhances the effect of NO by inhibiting PDE5, which is responsible for the breakdown of cGMP.

Sildenafil is selective against PDE5 in vitro, its activity against PDE5 exceeds the activity against other known phosphodiesterase isoenzymes: PDE6 - 10 times; PDE1 - more than 80 times; PDE2, PDE4, PDE7-PDE11 - more than 700 times. Sildenafil is 4000 times more selective against PDE5 compared to PDE3, which is of crucial importance, since PDE3 is one of the key enzymes regulating myocardial contractility.

Cardiological studies

The use of sildenafil in doses up to 100 mg did not lead to clinically significant ECG changes in healthy volunteers. The maximum decrease in systolic blood pressure in the supine position after taking sildenafil at a dose of 100 mg was 8.3 mmHg, and diastolic blood pressure was 5.3 mmHg. A more pronounced, but also transient effect on blood pressure was observed in patients taking nitrates.

In a study of the hemodynamic effect of sildenafil in a single dose of 100 mg in 14 patients with severe coronary artery disease (more than 70% of patients had stenosis of at least one coronary artery), systolic and diastolic blood pressure at rest decreased by 7% and 6%, respectively, and pulmonary systolic pressure decreased by 9%. Sildenafil did not affect cardiac output and did not disrupt blood flow in stenosed coronary arteries, and also led to an increase (by about 13%) in adenosine-induced coronary blood flow in both stenosed and intact coronary arteries.

In a double-blind placebo-controlled study, 144 patients with erectile dysfunction and stable angina, taking antianginal drugs (except nitrates), performed physical exercises until the severity of angina symptoms decreased. The duration of the exercise was significantly longer (19.9 sec; 0.9-38.9 sec) in patients taking sildenafil in a single dose of 100 mg compared with patients receiving placebo.

In a randomized, double-blind, placebo-controlled study, the effect of changing the dose of sildenafil (up to 100 mg) was studied in men (n=568) with erectile dysfunction and hypertension taking more than two antihypertensive drugs. Sildenafil improved erection in 71% of men compared to 18% in the placebo group. The frequency of adverse effects was comparable to that in other groups of patients, as well as in those taking more than three antihypertensive drugs.

Studies of visual disorders

In some patients, 1 hour after taking sildenafil at a dose of 100 mg, a slight and transient impairment of the ability to distinguish shades of color (blue / green) was detected using the Farnsworth-Munsel 100 test. After 2 hours after taking the drug, these changes were absent. It is believed that color vision impairment is caused by inhibition of PDE6, which is involved in the process of light transmission in the retina of the eye. Sildenafil had no effect on visual acuity, contrast perception, electroretinogram, intraocular pressure or pupil diameter.

In a placebo-controlled cross-sectional study of patients with proven early-age macular degeneration (n=9), sildenafil in a single dose of 100 mg was well tolerated. There were no clinically significant changes in vision assessed by special visual tests (visual acuity, Amsler lattice, color perception, color passage modeling, Humphrey perimeter and photostress).

Effectiveness

The efficacy and safety of sildenafil were evaluated in 21 randomized, double-blind, placebo-controlled trials lasting up to 6 months in 3,000 patients aged 19 to 87 with erectile dysfunction of various etiologies (organic, psychogenic or mixed). The effectiveness of the drug was evaluated globally using an erection diary, an international index of erectile function (a validated questionnaire on the state of sexual function) and a partner survey. The efficacy of sildenafil, defined as the ability to achieve and maintain an erection sufficient for satisfactory sexual intercourse, has been demonstrated in all studies conducted and has been confirmed in long-term studies lasting 1 year. In fixed-dose studies, the ratio of patients who reported that therapy improved their erection was: 62% (sildenafil 25 mg dose), 74% (sildenafil 50 mg dose) and 82% (sildenafil 100 mg dose), compared with 25% in the placebo group. Analysis of the international index of erectile function showed that in addition to improving the erection, treatment with sildenafil also increased the quality of orgasm, allowed to achieve satisfaction from sexual intercourse and general satisfaction.

According to the generalized data, 59% of diabetic patients, 43% of patients who underwent radical prostatectomy and 83% of patients with spinal cord injuries were among the patients who reported an improvement in erection during treatment with sildenafil (compared with 16%, 15% and 12% in the placebo group, respectively).

With a single dose of the drug up to 800 mg, adverse events were comparable to those when taking sildenafil in lower doses, but they were more common. Treatment: symptomatic therapy. Hemodialysis does not accelerate the clearance of sildenafil, because the latter actively binds to plasma proteins and is not excreted in the urine. According to the registered indication, the drug is not intended for use in women.

  • The most common side effects were headache and "hot flashes".
  • Side effects are usually mild or moderate and are transient.
  • In studies using a fixed dose, it was found that the frequency of some adverse events increases with increasing dose.

The frequency of adverse reactions is determined as follows:

  1. Very often
    10%
  2. Often
    1% and
  3. Infrequently
    0.1% and
  4. Rarely
    0.01% and

Very rarely

The frequency is unknown
it is impossible to determine based on the available data
From the immune system: infrequently - hypersensitivity reactions (including skin rash), allergic reactions.