Pharmacological properties
Antiviral agent. Active against herpes simplex virus types 1 and 2 (herpes simplex), shingles virus (varicella zoster), Epstein-Barr virus, cytomegalovirus.
The antiviral activity of the drug is highly selective and is due to its competitive interaction with the virus enzyme thymidine kinase. Under the influence of thymidine kinase, acyclovir is converted into mono-, di-, and then into acyclovir triphosphate, the latter being incorporated into DNA, which is synthesized for new viruses. Thus, viral DNA is formed, the structure of which contains a defect, which leads to inhibition of replication of new generations of viruses.
After oral administration, acyclovir is partially absorbed from the intestine. Binding to plasma proteins is 9-33%. The concentration of acyclovir in the cerebrospinal fluid is 50% of the concentration in plasma.
The only metabolite of the drug is 9-carboxymethoxymethylguanine. Most of acyclovir is excreted by the kidneys in unchanged form, 10-15% - in the form of a metabolite. The rate of excretion of the drug slows down with age, but the half-life increases slightly.
In chronic renal failure, the half-life is 19.5 hours; in the case of hemodialysis, the figure decreases to 5.7 hours, and the concentration in the blood plasma decreases to 60% of the initial value.
Indication
Treatment of infections of the skin and mucous membranes caused by herpes simplex viruses types 1 and 2, both primary and recurrent, including genital herpes.
Prevention of infections caused by Herpes simplex viruses types 1 and 2.
Prevention of the development of primary infection and prevention of recurrence of infections caused by Herpes simplex viruses of types 1 and 2 in patients with reduced immunity, including recipients of organ or bone marrow transplantation, severe forms of immunodeficiency, including HIV infection.
Infections caused by Varicella zoster viruses (chickenpox and shingles).
Application
For infections caused by the herpes simplex virus, adults and children from 2 years of age are prescribed 200 mg of Acic 5 times a day for 5-10 days;
children under 2 years old - 100 mg, 5 times a day (1/2 the adult dose) for 5-10 days.
For the prevention of recurrent genital herpes, the drug is prescribed at 400 mg 2 times a day or 200 mg 4 times a day; the course of treatment is from 6 months to 1 year.
For the prevention of herpetic infection in patients with immunodeficiency or after bone marrow transplantation, Acic is prescribed at 400 mg 4 times a day throughout the entire period of risk of infection.
In the treatment of Herpes zoster ophthalmicus, the dose of the drug is 800 mg, 5 times a day for 7-10 days.
The doses of the drug in the treatment of chickenpox depend on the age of the child (on average 20 mg/kg per dose, but not more than 800 mg) and are:
up to 2 years - 200 mg 4 times a day for 5 days;
from 2 to 6 years - 400 mg 4 times a day for 5 days;
from 6 years old - 800 mg 4 times a day for 5 days.
Patients with chronic renal failure with creatinine clearance less than 10 ml/min are prescribed the drug at a dose of 200 mg every 12 hours for the treatment of infections caused by the Herpes simplex virus, and up to 800 mg every 12 hours for the treatment of infections caused by the Herpes zoster virus.
Contraindication
Hypersensitivity to acyclovir.
Side effects
On the part of the gastrointestinal tract: nausea, vomiting, diarrhea, intestinal colic, moderate short-term increase in bilirubin and transaminase levels are possible.
On the part of the kidneys: in very rare cases - a slight increase in the concentration of urea and creatinine in the blood.
Skin: rashes are possible, which quickly disappear after discontinuation of the drug.
From the side of the central nervous system: in isolated cases, headache, chronic fatigue syndrome, drowsiness or psychomotor agitation, hallucinations, confusion have been noted.
Special instructions
Treatment with the drug should be prescribed as early as possible, if possible - in the prodromal period. The state of the body's immune system is important for the implementation of the therapeutic effect. The drug is more effective in patients with unchanged immunity. In patients with reduced immunity, with multiple repeated courses of treatment, the formation of virus resistance to acyclovir sometimes occurs.
The use of the drug during pregnancy is possible only if absolutely necessary. Breastfeeding is discontinued if the drug is necessary.
Interactions
With simultaneous use of the drug with probenecid, the concentration of acyclovir in the blood plasma increases.
Overdose
In case of oral administration of more than 5 g of acyclovir, it is recommended to monitor the state of renal function.
In cases of overdose, measures are taken to remove the drug (gastric lavage, administration of absorbents), in severe cases - by hemodialysis.
Storage conditions
In a dry, dark place at a temperature not exceeding 25 °C.
