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 infections of the skin and mucous membranes 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 for patients with severe immunodeficiency: with HIV infection (stage of AIDS, early clinical manifestations and detailed clinical picture) and in patients who have undergone bone marrow transplantation.

– Treatment of primary and recurrent infections caused by the Varicella zoster virus (chickenpox, as well as herpes zoster).

Pharmacological effect

Pharmacodynamics

Acyclovir is an antiviral drug, a synthetic analogue of an acyclic purine nucleoside, which has a highly selective effect on herpes viruses. Inside virus-infected cells, under the influence of viral thymidine kinase, a series of sequential reactions of transformation of acyclovir into mono-, di- and triphosphate of acyclovir takes place. Acyclovir triphosphate is incorporated into the viral DNA chain and blocks its synthesis through competitive inhibition of viral DNA polymerase.

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

Pharmacokinetics

When taken orally, bioavailability is 15-30%. Acyclovir penetrates well into all organs and tissues of the body, including the brain and skin. Plasma protein binding is 9-33% and is independent of its plasma concentration. The concentration in the cerebrospinal fluid is about 50% of its concentration in plasma. Acyclovir crosses the placental barrier and accumulates in breast milk. The maximum concentration after oral administration of 200 mg 5 times a day is 0.7 mcg/ml, the time to reach the maximum concentration is 1.5-2 hours.

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

Special instructions

Long-term or repeated treatment with acyclovir in patients with reduced immunity can lead to the emergence of strains of viruses that are insensitive to its action.

Use strictly as prescribed by your doctor to avoid complications.

Prescribe with caution to patients with impaired renal function and elderly patients due to an increase in the half-life of acyclovir.

When using the drug, it is necessary to ensure the supply of a sufficient amount of fluid.

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

Acyclovir does not prevent the sexual transmission of herpes, so during the treatment period it is necessary to abstain from sexual intercourse, even in the absence of clinical manifestations.

Active ingredient

Acyclovir

Composition

1 tablet contains:

Active substance: acyclovir 200 mg.

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

Pregnancy

Use during pregnancy is only possible if the expected benefit to the mother outweighs the potential risk to the fetus. Acyclovir crosses the placental barrier and accumulates in breast milk. If it is necessary to take acyclovir during lactation, interruption of breastfeeding is required.

Contraindications

Hypersensitivity to acyclovir, ganciclovir, famciclovir, 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, elderly people and patients receiving large doses, especially against the background of dehydration, impaired renal function, neurological disorders or neurological reactions to cytotoxic drugs (including in history).

Side Effects

From the gastrointestinal tract: in isolated cases – abdominal pain, nausea, vomiting, diarrhea.

Laboratory indicators: transient slight increase in the activity of liver enzymes, rarely – a slight increase in urea and creatinine levels, hyperbilirubinemia, leukopenia, erythropenia.

From the central nervous system: rarely – headache, weakness; in some cases, tremor, dizziness, increased fatigue, exhaustion, drowsiness, insomnia, confusion, hallucinations, decreased concentration.

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

Other: rarely – alopecia, peripheral edema, blurred vision, lymphadenopathy.

Interaction

Concomitant use with probenecid leads to an increase in the mean half-life and a decrease in the clearance of acyclovir. When taken simultaneously with nephrotoxic drugs, the risk of renal dysfunction increases.

Overdose

Oral administration of 20 g of acyclovir did not lead to the development of specific symptoms.

Side effects may occur from the central nervous system – convulsions, tremors, lethargy.

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

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

Short product description

Antiviral agent.

Storage conditions

At a temperature not exceeding 25 ° C, in a place protected from light. Keep out of the reach of children.

Shelf life

4 years. Do not use the drug after the expiration date.

Manufacturer

Cadila Pharmaceuticals Ltd, India