Acyclovir

General characteristics. Structure:

Active ingredient: 212 mg of an acyclovir (it is equivalent to the maintenance of an anhydrous acyclovir of 200 mg).

Excipients: lactose monohydrate, magnesium stearate, prezhelatinizirovanny starch, sodium carboxymethylcellulose.

Antiviral means.

Pharmacological properties:

Pharmacokinetics. The acyclovir is an analog of a purine nucleoside of a dezoksiguanidin, the DNA normal component. Similarity of structures of an acyclovir and dezoksiguanidin allows an acyclovir to interact with virus enzymes that leads to interruption of reproduction of a virus. After implementation of an acyclovir in the cell affected with herpes under the influence of the thymidinekinase allocated by a virus, the acyclovir turns into an acyclovir monophosphate which enzymes of a host cell turns into an acyclovir diphosphate, and then into an active form an acyclovir triphosphate which blocks implementation of virus DNA.

Drug affects selectively synthesis of virus DNA. The acyclovir triphosphate practically does not influence DNA replication of a host cell (a cell of the person). The acyclovir at herpes prevents formation of new elements of rash, reduces probability of skin dissimination and visceral complications, accelerates formation of crusts, weakens pains in an acute phase of the surrounding herpes. Drug has also immunopromoting effect.

Pharmacodynamics. At intake, the acyclovir is soaked up only partially (about 20%). An elimination half-life at intake and introduction to a vein about 3 h. It is allocated generally with kidneys in not changed look, partially in the form of a metabolite (9-karboksimetoksimetilguanin). At a renal failure the elimination half-life considerably increases (up to 19,5 h).

Indications to use:

The acyclovir is applied to treatment of a simple herpes infection of skin and mucous membranes, chicken pox, shingles, to suppression of a returnable infectious viral herpes simplex at immunocompetent patients and at patients with reduced immunity.

Route of administration and doses:

Pill is taken inside, without chewing, washing down with a small amount of water.

Adults. Treatment of simple herpes infections: 200 mg five times a day with four-hour intervals, except for night time. Treatment duration usually makes five days, but in case of heavy primary infection it should be prolonged. At patients with disturbances of intestinal absorption or heavy disturbance of immunity of a dose about  400 mg can be doubled (or intravenous forms are applied). Treatment has to be begun as soon as possible, it is preferable in a prodromal stage (at emergence of nonspecific symptoms of a disease) or at emergence of the first centers of defeat in a case of a returnable infection.

Suppression of a herpes infection at patients with the broken immunity: 200 mg four times a day with six-hour intervals. The dose of 400 mg twice a day with a twelve-hour interval is suitable for many patients. Doses of 200 mg three times a day with an eight-hour interval or 200 mg twice a day with a twelve-hour interval can be in certain cases effective. Some patients can have exacerbations of an infection at the general dose      of 800 mg. Prolonged treatment. Each six-twelve months therapy has to be interrupted for observation of possible changes in a disease.

Prevention of a herpes infection at immunocompetent bolnykh:200 mg four times a day with an interval six hours. At patients with oppressed intestinal absorption or heavy immune disturbances the dose can be increased by reception to 400 mg (or intravenous forms are applied). Use duration for the purpose of prevention is defined by the risk period.

Treatment of chicken pox and shingles: 800 mg five times a day with a four-hour interval, except for night time. Treatment has to continue seven days. At patients with disturbances of intestinal absorption or with heavy immune disturbances intravenous administration most approaches.

At treatment of shingles the best results are achieved at most quick start of treatment, at emergence of the first skin rashes. Treatment of chicken pox at patients with the broken immunity has to be begun within 24 hours after emergence of the first rash.

Children. Treatment and prevention simple герпеса:детям are more senior than two years in adult dosages. At children up to two years: half doses.

Treatment of the infections caused by Varicella: treatment has to last five days.

Up to two years: 200 mg four times a day. Doses can be defined at the rate of 20 mg/kg of body weight four times a day. The general day dose should not exceed 800 mg.

From two to five years: 400 mg four times a day.

Six years are also more senior: 800 mg four times a day.

Doses can be defined at the rate of 20 mg/kg of body weight four times a day.

Patients with a disease will not lead pochek:rekomenduyemy doses at treatment of a herpes simplex to accumulation of an acyclovir over the entered level at patients with oppressed function of kidneys. At heavy renal disturbances, clearance of creatinine less than 10 ml/min., doses of 200 mg twice a day with an interval of 12 hours are recommended.

For treatment of Varicellai Herpeszostermogut to be recommended the following doses:

Renal disturbances of moderate degree clearance of creatinine of 10-25 ml/min., 800 mg three times a day with an eight-hour interval.

Heavy renal disturbances, clearance of creatinine less than 10 ml/min., 800 mg twice a day with a twelve-hour interval.

Features of use:

It is necessary to consider that at use of an acyclovir development of an acute liver failure owing to formation of a deposit from acyclovir crystals is possible that it is especially probable at simultaneous use of nephrotoxic drugs, at patients with renal failures and at insufficient water loading.

At use of an acyclovir it is necessary to control urea nitrogen level in blood and creatinine in a blood plasma.

Treatment of patients of advanced age should be carried out at sufficient increase in water loading and under observation of the doctor as at this category of patients the acyclovir elimination half-life increases.

Side effects:

From digestive tract and печени:редко – moderate short-term increase in level of bilirubin and activity of enzymes of a liver; in isolated cases – nausea vomiting, diarrhea, intestinal colic.

From the central nervous sistemy:pra systematic use of drug the headache, weakness, in isolated cases – dizziness, confusion of consciousness, a hallucination, drowsiness, spasms are seldom observed. These reactions are most probable at the patients accepting high doses of drug intravenously and also at patients with a renal failure and AIDS, and have usually reversible character.

From a pochek:pra reception of an acyclovir slight increase of concentration of urea and creatinine in blood inside is seldom observed.

Dermatological a reaktsii:vozmozhna the skin rash passing at drug withdrawal it is rare – a diffusion hair loss.

Interaction with other medicines:

At simultaneous use пробенецид reduces canalicular secretion of an acyclovir and by that increases concentration in a blood plasma and an acyclovir elimination half-life.

At simultaneous use with nephrotoxic drugs the risk of development of nephrotoxic action increases (especially at patients with an impaired renal function).

Contraindications:

The acyclovir is contraindicated at persons with hypersensitivity to an acyclovir or to any of auxiliary components of drug.

Overdose:

At a dose of oral administration of 4 g a day within seven days without toxic effects. At overdose more than 5 g are recommended medical observation of the patient. A symptomatic treatment and supporting. The acyclovir is removed at a hemodialysis.

Storage conditions:

List B. To store in the place protected from moisture and light at a temperature not above +25 °C. To store in the place, unavailable to children. Not to use after the period of validity specified on packaging. Period of validity of 5 years.

Issue conditions:

According to the recipe

Packaging:

On 10, 20 or 30 tablets in banks polymeric. On 10 tablets in a blister strip packaging from a film of polyvinyl chloride and aluminum foil. Bank or 1, 2, 3 blister strip packagings in a cardboard pack.