Acyclovir

General characteristics. Structure:

Active agent: an acyclovir of 200 mg in terms of anhydrous substance;

Excipients: lactose (sugar milk) - 150,8 mg, potato starch - 46,9 mg, sucrose - 0,2 mg, magnesium stearate - 3,0 mg, povidone (polyvinylpirrolidone) - 8,0 mg, stearic acid - 1,1 mg.

Pharmacological properties:

Antiviral drug, the synthetic analog of an acyclic purine nucleoside possessing highly selective effect on herpes viruses. In the cells infected with a virus under the influence of a virus thymidinekinase there takes place a number of consecutive reactions of transformation of an acyclovir in mono - di - and acyclovir triphosphate. Atsiklo-virtrifosfat is built in a chain of virus DNA and blocks its synthesis by means of competitive inhibition of a virus DNA polymerase. In vitro an acyclovir is effective against a herpes simplex virus — Herpes simplex of type I and II, against the Varicella zoster virus; higher concentration are required for inhibition of a virus of Epstein-Burra. In vitro an acyclovir therapeutic and preventively is effective first of all at the viral infections caused by Herpes simplex.
At intake biological availability makes 15-30%. The acyclovir well gets into all bodies and body tissues, including a brain and skin. Linkng with proteins of plasma makes 9-33% and does not depend on its concentration in plasma. Concentration in cerebrospinal fluid makes about 50% of its concentration in plasma. The acyclovir gets through a placental barrier and collects in breast milk. The maximum concentration after appointment in 200 mg of 5 times a day — 0,7 mkg/ml, time of achievement of the maximum concentration — 1,5-2 hours.
It is metabolized in a liver with formation pharmacological of inactive connection of a 9-karboksimetoksimetilguanin. The elimination half-life at adults with normal function of kidneys makes 2-3 hours. Patients with a heavy renal failure have an elimination half-life — 20 hours, at a hemodialysis — 5,7 hours (at the same time concentration of an acyclovir in plasma decreases to 60% of a reference value). About 84% are allocated with kidneys in an invariable look and 14% — in the form of a metabolite. The renal clearance of an acyclovir makes 75-80% of the general plasmatic clearance. Less than 2% of an acyclovir are brought out of an organism through intestines.

Indications to use:

- Treatment of infections of skin and the mucous membranes caused by the Herpes simplex viruses of type I and II both primary, and secondary, including genital herpes.
- Prevention of exacerbations of the recurrent infections caused by the Herpes simplex viruses of type I and II at patients with the normal immune status.
Prevention of primary and recurrent infections caused by the Herpes simplex viruses of type I and II in patients with an immunodeficiency.
- As a part of complex therapy of patients with the expressed immunodeficiency: at HIV infection (AIDS stage, early clinical manifestations and the developed clinical picture) and at the patients who transferred transplantation of marrow.
- Treatment of primary and recurrent infections caused by the Varicella zoster virus (chicken pox, and also shingles — Herpes zoster.

Route of administration and doses:

Inside. Drug is accepted in time or right after meal and is washed down with enough water.
The mode of dosing is set individually depending on severity of a disease. At the treatment of infections of skin and mucous membranes caused by Herpes simplex of type I and II: Adults: drug is appointed on 200 mg of 5 times a day within 5 days with 4-hour intervals during the day and from the 8th an hour interval to night. In more hard cases of a disease the course of treatment can be prolonged on doctor's orders up to 10 days. As a part of complex therapy at the expressed immunodeficiency, including at the developed clinical picture of HIV infection (including, early clinical displays of HIV infection and a stage of AIDS), after implantation of marrow appoint 400 mg of 5 times a day. For prevention of a recurrence of the infections caused by the Herpes simplex viruses of type I and II to patients with the normal immune status and at a recurrence of a disease appoint 200 mg 4 times a day each 6 hours, duration of a course from 6 to 12 months.

For prevention of a recurrence of the infections caused by the Herpes simplex viruses of type I and II, the adult with an immunodeficiency,    drug    is recommended to appoint on 200 mg 4 times a day each 6 hours, the maximum dose — to 400 mg of an acyclovir of 5 times a day in dependence on weight of an infection. Children: for treatment of the infection caused by Herpes simplex and prevention of this infection at patients with the weakened host defense, children are more senior than 3 years receive the same dose, as adults.

At treatment of the infections caused by Varicella zoster:
Adults: on 800 mg of 5 times a day each 4 hours in the afternoon and from the 8th an hour interval for the night. Duration of a course of treatment is 7-10 days. Children: at chicken pox appoint 20 mg / кг4 once a day within 5 days (the maximum single dose of 800 mg), to children from 3rd to 6 years: 400 mg 4 times a day, are more senior than 6 years: 800 mg 4 times a day within 5 days. At treatment of the infections caused by Herpes zoster adult appoint 800 mg 4 times a day each 6 hours within 5 days. At patients with a renal failure: At treatment and prevention of the infections caused by Herpes simplex at patients with clearance of creatinine a dosage of drug it is necessary to lower less than 10 ml/min. to 200 mg 2 times a day from 12 hour intervals.

At treatment of the infections caused by Varicella zoster at patients with clearance of creatinine less than 10 ml/min. are recommended to lower a drug dosage to 800 mg 2 times a day from 12 hour intervals; at clearance of creatinine to 25 ml/min. about 800 mg 3 times a day with the 8th hour intervals are appointed.

Features of use:

To apply strictly on doctor's orders in order to avoid complications at adults and children is more senior than 3 years. With care appoint to patients with renal failures, patients of advanced age in connection with increase in an elimination half-life of an acyclovir.
At use of drug it is necessary to provide receipt of enough liquid. At administration of drug it is necessary to control function of kidneys (level of urea of blood and creatinine of a blood plasma).
The acyclovir does not prevent transfer of herpes sexually therefore during treatment it is necessary to abstain from sexual contacts, even in the absence of clinical manifestations.

Side effects:

Drug is usually well transferred.
- From digestive tract: in isolated cases — abdominal pains, nausea, vomiting, diarrhea.
- In blood: passing slight increase of activity of enzymes of a liver, is rare — small increase in levels of urea and creatinine, a hyperbilirubinemia, a leukopenia, an erythropenia.
- From the central nervous system: seldom — a headache, weakness; in some cases tremor, dizziness, increased fatigue, exhaustion, drowsiness, sleeplessness, paresthesias, confusion of consciousness, hallucination, decrease in concentration of attention, agitation.
- Allergic reactions: anaphylactic reactions, skin rash, itch, Lyell's disease, small tortoiseshell, multiformny exudative erythema, including Stephens-Johnson's syndrome, fever.
- Other: seldom — an alopecia, peripheral hypostases, a vision disorder, a limfoadenopatiya, a mialgiya, an indisposition.

Interaction with other medicines:

Simultaneous use with probenetsidy leads to increase in an average elimination half-life and decrease in clearance of an acyclovir. At a concomitant use with nephrotoxic drugs the risk of disturbance of functions of kidneys increases.
Strengthening of effect is noted at co-administration of immunostimulators.

Contraindications:

Hypersensitivity to an acyclovir, a gantsi-klovir or any excipient of drug.
Administration of drug is contraindicated in the period of a lactation.
Children's age up to 3 years (for this dosage form).

With CARE: pregnancy; the elderly people and patients receiving high doses, especially against the background of dehydration; renal failure; neurologic disturbances or neurologic reactions to reception of cytotoxic medicines (including in the anamnesis).

PREGNANCY AND LACTATION
The acyclovir gets through a placental barrier and collects in breast milk. Use during pregnancy is possible only in that case when the estimated advantage for mother exceeds potential risk for a fruit. In need of reception of an acyclovir in the period of a lactation breastfeeding interruption is required.

Overdose:

Overdose cases after oral administration of an acyclovir are not registered.

Storage conditions:

List B. To store in the dry, protected from light place at a temperature not above 25 °C. To store in the place, unavailable to children.

Issue conditions:

According to the recipe

Packaging:

Tablets of 400 mg.
On 10, 20 tablets in a blister strip packaging from a film of the polyvinyl chloride and printing aluminum foil varnished.
On 10, 20, 30, 40, 50 or 100 tablets in a container polymeric for medicines. One container or 1,2,3,4,5,6,8 or 10 blister strip packagings together with the application instruction place in a pack from a cardboard.