Вацирекс

General characteristics. Structure:

Active ingredient: 500 mg of a valatsiklovir in the form of a hydrochloride.

Excipients: maltodextrin, potato starch, gidroksipropilmetiltsellyuloz (gipromelloz), sodium lauryl sulfate, кросповидон (Kollidon CL) of magnesium stearate

Excipients for a cover: gidroksipropilmetiltsellyuloz (gipromelloz), polyethyleneglycol 6000 (macrogoal 6000), titanium dioxide

Вацирекс — new antiviral drug for the treatment of diseases of skin and mucous membranes caused by a herpes virus.

Pharmacological properties:

Pharmacodynamics. Specific inhibitor of a DNA polymerase of viruses of herpes. Blocks synthesis of virus DNA and replication of viruses. In a human body turns into an acyclovir and L-valine; as a result of phosphorylation active triphosphate of an acyclovir which competitively suppresses a virus DNA polymerase is formed of an acyclovir. The first stage of phosphorylation occurs under the influence of virusospetsifichesky enzyme (for the viruses Herpes simplex, Varicella zoster, Epstein-Barre's virus — a virus thymidinekinase which is found only in the cells infected with a virus).

For TsMV cytomegalovirus selectivity of drug is caused by the fact that phosphorylation is partially mediated by an UL97 phosphotransferase gene product. in vitro concerning the Herpes simplex 1 and 2 viruses of types, the Varicella zoster virus, Epstein-Barre's virus, TsMV and a human virus of herpes 6 types is active.

Pharmacokinetics. Absorption — high, quickly and almost completely turns into an acyclovir and L-valine. Bioavailability of an acyclovir at reception of 1 g of a valatsiklovir — 54% (is 3-5 times higher, than at reception of an acyclovir inside). After use of a valatsiklovir in a dose of 1 g 4 times a day the area under a curve "concentration — time" (AUC) is approximately equal to AUC at in introduction of an acyclovir in a dose of 5 mg each 8 h. The maximum concentration in plasma (Cmax) after a single dose of 1 g — 15-25 µmol/ml, time of achievement of the maximum concentration (TCmax) — 1,6-2,1 h; by 3 h nemetabolizirovanny валацикловир in plasma is not defined. Communication with proteins of plasma valatsiklovira-13-18%, an acyclovir — 9-33%.

The acyclovir is widely distributed in fabrics and liquids of an organism, including a brain, kidneys, lungs, a liver, the lacrimal liquid, intestines, muscles, a spleen, a uterus, a mucous membrane and a secret of a vagina, sperm, amniotic liquid, the SMZh spino-brain liquid (50% of concentration in plasma), liquid of herpetic bubbles. The highest concentration are created in kidneys, a liver and intestines. Gets through a placenta and into breast milk.

Elimination half-life of T1/2 of a valatsiklovir — less than 30 min.; an acyclovir — 2,5-3,3 h, at an end-stage of a renal failure — 14 h, at elderly patients (65-83 years) — 3,3-3,7.

It is removed by kidneys (45,6%), less than 1% — in not changed view and with fecal masses (47,12%) during 96 h are preferential in the form of an acyclovir and its metabolite of a 9-karboksimetoksimetilguanin.

Indications to use:

At adults: shingles; the diseases of skin and mucous membranes caused by the Herpes simplex virus (including genital herpes); prevention of a recurrence of the diseases caused by the Herpes simplex virus.

At adults and children since 12 years: prevention of a Cytomegaloviral infection at organ transplantation.

Route of administration and doses:

Inside, for treatment of shingles — on 1 g 3 times a day within 7 days; for Herpes simplex treatment — on 500 mg 2 times a day. At a recurrence of the diseases caused by the Herpes simplex virus, treatment is begun in a prodromal stage or right after emergence of the first symptoms within 5 days; if necessary at the first stage duration of treatment is increased up to 10 days.

Against the background of a chronic renal failure the dose is reduced: at the surrounding herpes — on 1 g each 12 h at clearance of creatinine of 30-49 ml/min.; 1 time a day at clearance of creatinine of 10-29 ml/min.; on 500 mg of 1 times a day at clearance of creatinine less than 10 ml/min.; at simple (including genital) herpes — on 500 mg each 12 h at clearance of creatinine of 30-49 ml/min. or 1 times a day at clearance of creatinine less than 30 ml/min.; in case of a hemodialysis drug is appointed after it.

Features of use:

Pregnancy. There are limited data on use of a valatsiklovir at pregnancy. Use is possible only when the potential advantage for mother exceeds possible risk for a fruit.

Valatsiklovir in not changed look was not defined in mother's plasma, breast milk. The acyclovir, the main metabolite of a valatsiklovir, is allocated with breast milk. Considering it, it is necessary to appoint with care Vatsireks of mother in the period of a lactation.

With normal immunity viruses with a hyposensitivity occur at patients exclusively seldom; rather more often these viruses are found in persons with the expressed immunodeficiency (at recipients of internals or marrow; the patients receiving chemotherapy concerning the malignant new growths infected with HIV). A hyposensitivity of viruses to drug is caused by phenotypical deficit of a thymidinekinase in the cells infected with a virus while virulence of such viruses is close to that of "wild" viruses.

Patients of advanced age during treatment need to increase the volume of the consumed liquid.

In the absence of the expressed renal failures of correction of the mode of dosing it is not required.

Experience of use of drug for children is insufficient.

At treatment of genital herpes it is necessary to avoid sexual contacts since drug does not protect from transmission of infection.

Administration of drug in high doses at the states which are followed by the expressed immunodeficiency (transplantation of marrow, clinically expressed HIV infection forms, transplantation of a kidney) led for a long time to development of a Werlhof's disease and a gemolitikouremichesky syndrome, up to a lethal outcome.

Side effects:

Nausea, vomiting, gastralgia, loss of appetite, dizziness, headache, excessive fatigue; a renal failure, a mikroangiopatiya, hemolitic anemia, thrombocytopenia (at the patients with the expressed immunodeficiency receiving валацикловир in high doses (8 g/days) and a long time), increase in activity of aspartate aminotransferase (nuclear heating plant).

Interaction with other medicines:

Cimetidinum and blockers of canalicular secretion reduce effect (reduce speed, but not completeness of transformation into an acyclovir).

Nephrotoxic medicines increase risk of development of nephrotoxicity and disturbances from the central nervous system.

Contraindications:

Hypersensitivity, transplantation of marrow, clinically expressed HIV infection forms, transplantation of a kidney, children's age (up to 12 years — for prevention of a Cytomegaloviral infection at organ transplantation, up to 18 years — according to other indications), a lactose intolerance, deficit of lactase, glyukozo-galaktozny malabsorption.

With care: Liver/renal failure, pregnancy, lactation period.

Overdose:

Symptoms: adjournment of drug in renal tubules.

Treatment: a hemodialysis (at an acute renal failure and an anury).

Storage conditions:

List B. In the dry, protected from light place, at a temperature not above 25 °C. To store in the place, unavailable to children! A period of validity - 2 years. Not to use after the expiry date specified on packaging.

Issue conditions:

According to the recipe

Packaging:

Tablets, film coated 500 mg. On 6,7 or 10 tablets in a blister strip packaging from a film of the polyvinyl chloride and printing aluminum foil varnished. On 1,2,3,4,5,6,7 blister strip packagings together with a design on use place in a pack from a cardboard.