Vivorax, tablets 200 mg 10 pcs

Pharmacodynamics

Acyclovir is an antiviral drug, a synthetic analog of acyclic purine nucleoside with highly selective action on herpes viruses. A series of sequential reactions of acyclovir transformation into mono-, di- and triphosphate acyclovir takes place inside virus-infected cells under the action of viral thymidine kinase. Acyclovir triphosphate integrates into the chain of viral DNA and blocks its synthesis through competitive inhibition of viral DNA polymerase.

In vitro acyclovir is effective against herpes simplex virus – Herpes simplex virus types I and II, against Varicella zoster virus; higher concentrations are required for inhibition of Epstein-Barr virus. In vivo acyclovir is therapeutically and prophylactically effective primarily against viral infections caused by Herpes simplex.

Pharmacokinetics

In oral administration the bioavailability is 15-30%. Acyclovir penetrates well into all organs and tissues of the body, including the brain and skin. Binding to plasma proteins is 9-33% and does not depend on its concentration in plasma. Concentration in cerebrospinal fluid is about 50% of its concentration in plasma. Acyclovir penetrates the placental barrier and accumulates in breast milk. Maximum concentration after oral administration of 200 mg 5 times a day is 0.7 mcg/ml, time to reach maximum concentration is 1.5-2 hours.

It is metabolized in the liver to form pharmacologically inactive compound 9-carboxymethoxymethylguanine. The half-life in adults with normal renal function is 2-3 hours. In patients with severe renal insufficiency the half-life is 20 hours, in hemodialysis – 5.7 hours (in this case the concentration of acyclovir in plasma decreases to 60% of the initial value). About 84% is excreted by the kidneys unchanged, and 14% – as a metabolite. Renal clearance of acyclovir is 75-80% of the total plasma clearance. Less than 2% of acyclovir is excreted from the body through the intestine.

Indications

– Treatment of skin and mucous membrane infections caused by Herpes simplex viruses type I and II, both primary and secondary, including genital herpes.

– Prevention of exacerbations of recurrent infections caused by Herpes simplex viruses type I and II in patients with normal immune status. Prevention of primary and recurrent infections caused by Herpes simplex viruses type I and II in patients with immunodeficiency.

– As part of complex therapy of patients with severe immunodeficiency: in HIV-infection (stage of AIDS, early clinical manifestations and developed clinical picture) and in patients who have undergone bone marrow transplantation.

– Treatment of primary and recurrent infections caused by Varicella zoster virus (chicken pox as well as shingles – Herpes zoster).

Active ingredient

Composition

1 tablet contains:

The active substance: acyclovir 200mg.

Excipients: corn starch, lactose monohydrate, magnesium stearate, indigo carmine (E 132)

How to take, the dosage

Ingestion. The drug is taken during or immediately after meals and washed down with enough water. Treatment should be started as soon as possible, immediately after the appearance of the first symptoms of the disease.

The dosing regimen is set individually, depending on the severity of the disease.

In the treatment of infections of the skin and mucous membranes caused by Herpes simplex types I and II:

Adults: the drug is prescribed in 200 mg 5 times a day for 5 days with 4-hour intervals during the day and with 8-hour intervals at night. In more severe cases the course of treatment may be prolonged by doctor’s prescription up to 10 days. As part of complex therapy in cases of severe immunodeficiency, including developed clinical picture of HIV infection (including early clinical manifestations of HIV infection and AIDS stage), after bone marrow implantation – 400 mg five times a day.

For prophylaxis of recurrent infections caused by Herpes simplex viruses of types I and II, in patients with normal immune status and in case of relapse, 200 mg 4 times a day every 6 hours, duration of course is from 6 to 12 months.

For prophylaxis of infections caused by Herpes simplex viruses of types I and II in adults with immunodeficiency, the drug is recommended 200 mg 4 times a day every 6 hours, the maximum dose is up to 400 mg of acyclovir 5 times a day, depending on the severity of infection.

Children: For the treatment of infection caused by Herpes simplex and the prevention of this infection in patients with weakened immune defenses, children over 3 years of age receive the same dose as adults.

In the treatment of infections caused by Varicella zoster:

Adults: 800 mg 5 times a day every 4 hours during the day and 8 hours apart at night. The duration of treatment is 7-10 days.

Children: in case of chicken pox: 20 mg/kg 4 times a day for 5 days (maximum single dose – 800 mg), for children from 3 to 6 years: 400 mg 4 times a day, over 6 years: 800 mg 4 times a day for 5 days.

In the treatment of infections caused by Herpes zoster, adults are prescribed 800 mg 4 times a day every 6 hours for 5 days.

In patients with impaired renal function:

In the treatment and prevention of infections caused by Herpes simplex in patients with creatinine clearance less than 10 ml/min, the drug dosage should be reduced to 200 mg 2 times daily at 12-hour intervals.

In the treatment of infections caused by Varicella zoster in patients with creatinine clearance less than 10 ml/min, it is recommended to decrease the drug dosage to 800 mg 2 times daily with 12-hour intervals; in creatinine clearance up to 25 ml/min it is administered by 800 mg 3 times daily with 8-hour intervals.

Interaction

Special Instructions

Prolonged or repeated treatment with acyclovir in immunocompromised patients may lead to the emergence of virus strains that are insensitive to its action.

To use strictly as directed by your doctor to avoid complications.

Cautions are used with caution in patients with kidney dysfunction and in elderly patients because of the increased elimination half-life of acyclovir.

When using the drug it is necessary to ensure adequate intake of fluids.

When taking the drug, renal function (blood urea and plasma creatinine levels) should be monitored.

Acyclovir does not prevent sexual transmission of herpes, therefore during treatment it is necessary to abstain from sexual intercourse even if there are no clinical manifestations.

Synopsis

Contraindications

Hypersensitivity to acyclovir, ganciclovir, famiclovir, valacyclovir or any excipient of the drug.

The drug is contraindicated during lactation.

Children under 3 years of age (for this dosage form)

With caution: pregnancy, the elderly and patients receiving high doses, especially with dehydration, impaired renal function, neurological disorders or neurological reactions to cytotoxic drugs (including a history).

Side effects

Gastrointestinal tract: in single cases – abdominal pain, nausea, vomiting, diarrhea.

Laboratory parameters: transient slight increase in liver enzyme activity, rarely – slight increase in urea and creatinine levels, hyperbilirubinemia, leukopenia, erythropenia.

The central nervous system: rarely – headache, weakness; in some cases – tremor, dizziness, fatigue, exhaustion, drowsiness, insomnia, confusion, hallucinations, loss of concentration.

Allergic reactions: skin rash, itching, Lyell’s syndrome, urticaria, erythema multiforme, including Stevens-Johnson syndrome, fever.

Others: rarely alopecia, peripheral edema, visual disturbances, lymphoadenopathy.

Overdose

Orally administered 20 g of acyclovir did not cause specific symptoms.

CNS side effects may occur – seizures, tremors, lethargy.

In case of overdose after ingestion, it is necessary to induce vomiting (best within 30 minutes of taking the drug) and take absorbents.

In case of acute renal failure and anuria: maintenance of vital functions, hemodialysis. Peritoneal dialysis is less effective.

Pregnancy use

Similarities