Sildenafil is rapidly absorbed. The maximum concentration in the blood plasma after oral administration of the drug on an empty stomach is reached within 30 to 120 minutes. The average absolute oral bioavailability is 41% (range 25–63%). After oral administration of sildenafil, AUC and Cmax increase in proportion to the dose when taken in the recommended dose range (50-100 mg). When taking sildenafil with food, the absorption rate decreases, with an average delay of Tmax of 60 minutes and an average decrease of Cmax – 29%. The volume of distribution of sildenafil in a state of equilibrium concentration (Vd) is 105 liters, which indicates its distribution in the tissues. After a single oral dose of 100 mg, the average maximum total plasma concentration of sildenafil is approximately 440 ng / ml. Since sildenafil (and its main circulating metabolite N-desmethyl) is 96% bound to plasma proteins, the average maximum concentration of free sildenafil in plasma is 18 ng / ml (38 nM). Protein binding does not affect the total concentration of the drug. In healthy volunteers receiving sildenafil (single dose 100 mg), less than 0.0002% (average 188 ng) of the administered dose was determined 90 minutes after the administration in seminal fluid. Sildenafil metabolized predominantly by microsomal liver isoenzymes CYP3A4 (primary pathway) and CYP2C9 (secondary pathway). The main circulating metabolite is formed from sildenafil by N-demethylation. This metabolite has a phosphodiesterase profile of selectivity similar to that of sildenafil, and its in vitro PDE5 activity is approximately 50% of the activity of the original preparation. The concentration of this metabolite in plasma is approximately 40% of the concentration of sildenafil. Subsequently, the metabolite N-desmethyl is metabolized, while its half-life is about 4 hours. The total clearance of sildenafil is 41 l / h, while the terminal half-life is 3-5 hours. After oral or intravenous administration, sildenafil is excreted in the form of metabolites mainly with faeces (approximately 80% of the dose administered orally) and less in the urine (approximately 13% of the dose administered orally).
Indications for use
A drug Maksigra used to treat erectile dysfunction (to maintain an erection of the penis, sufficient for sexual intercourse).
Mode of application
Hg Art. and 7 mm. Hg Art.).
Symptoms of drug overdose Maksigra: increased symptoms of side effects. Treatment: symptomatic. Unknown specific antidote for sildenafil. Dialysis does not accelerate the elimination of sildenafil.
Store in a dry, dark place at a temperature not exceeding 25 ° C. Keep out of the reach of children!
Maksigra – tablets, coated 100 mg.On 1 or 4 tablets in packing. On 1 planimetric packing in a pack from a cardboard.
1 tablet Maksigra contains the active substance – sildenafil citrate