Valaciclovir - instructions for use, reviews, analogs and formulations (tablets 500 mg and 1000 mg) of a medicament for the treatment of herpes, chicken pox or chicken pox, shingles in adults, children and pregnancy. Composition

In this article, you can read the instructions for using the drug Valaciclovir. There are reviews of visitors to the site - consumers of this medication, as well as opinions of physicians specialists on the use of Valaciclovir in their practice. A big request is to actively add their feedback on the drug: the medicine helped or did not help get rid of the disease, which were observed complications and side effects, possibly not declared by the manufacturer in the annotation. Analogues of Valacyclovir in the presence of existing structural analogues.Use for the treatment of herpes, chicken pox or chicken pox, shingles in adults, children, as well as during pregnancy and lactation. Composition of the preparation.

Valaciclovir antiviral agent of the nucleoside analog group. Valacyclovir is an L-valine ester of acyclovir, thus being a prodrug.

After absorption into the blood, valaciclovir is almost completely converted into Acyclovir under the influence of the hepatic enzyme valaciclovir hydrolase. Acyclovir formed from valaciclovir, in turn, penetrates into the cells affected by the virus, where, under the influence of the viral enzyme, thymidine kinase is converted to monophosphate, then, under the influence of cellular kinases, into diphosphate and active triphosphate. Acyclovir triphosphate depresses the DNA polymerase and, thus, disrupts the replication of the DNA of the virus. In addition, the disruption of viral DNA replication may be the result of the incorporation of acyclovir into its structure. Thus, the high selectivity of valaciclovir in relation to tissues affected by the virus is explained by the fact that the 1 stage of the chain of phosphorylation reactions is mediated by an enzyme produced by the virus itself.

It is active against Herpes simplex virus types 1 and 2, Varicella zoster, cytomegalovirus, Epstein-Barr virus, human herpes virus 6.

Composition

Valaciclovir hydrochloride + excipients.

Pharmacokinetics

After oral administration, valacyclovir is well absorbed from the gastrointestinal tract, quickly and almost completely converted into acyclovir and L-valine under the action of the enzyme valacyclovirhydrolase. Bioavailability of acyclovir when taken from 1 g of valaciclovir is 54% and does not depend on food intake. The binding of valaciclovir to plasma proteins is very low - 15%. Valacyclovir is excreted in the urine, mainly in the form of acyclovir (more than 80% of the dose) and its metabolite 9-carboxymethoxymethylguanine, less than 1% of the drug is unchanged.

Indications

• shingles;
• infections of the skin and mucous membranes caused by the herpes simplex virus (including genital herpes);
• prevention of recurrence of diseases caused by the herpes simplex virus;
• prevention of cytomegalovirus infection, which develops during organ transplantation.

Forms of release

Tablets coated with 500 mg and 1000 mg.

Instructions for use and dosage

Inside (regardless of food intake).The dosage regimen is set individually, depending on the indications. It is recommended to start therapy as soon as possible, the greatest effectiveness is noted if the treatment was started within 48 hours from the first appearance of signs or symptoms of the disease (rashes, pain or burning sensation).

With shingles, 1000 mg 3 times a day for 7 days.

With simple herpes, including genital recurrent herpes, - 500 mg 2 times a day for 5-10 days.

Against the background of renal failure, the dosing regimen is set depending on the creatinine clearance; in the case of hemodialysis, the drug is prescribed after it.

Side effect

• nausea, vomiting;
• feeling of discomfort, abdominal pain;
• diarrhea;
• anorexia;
• transient increase in liver function;
• headache;
• fatigue;
• dizziness;
• confusion of consciousness;
• impaired consciousness;
• hallucinations;
• anxiety;
• tremor;
• coma (usually in patients with impaired renal function or other predisposing factors);
• rash;
• hives;
• itching;
• angioedema;
• anaphylaxis;
• thrombocytopenia;
• dyspnea;
• impaired renal function;
• pain in the kidneys;
• photosensitization.

Contraindications

• increased sensitivity to valacyclovir, acyclovir.

Application in pregnancy and lactation

Adequate and strictly controlled studies of the safety of the use of valacyclovir during pregnancy and lactation are not conducted. Use in this category of patients is possible in cases where the expected benefit of therapy for the mother exceeds the potential risk to the fetus or infant.

It is known that acyclovir, a metabolite of Valaciclovir, is excreted in breast milk in concentrations that are 0.6-4.1 times higher than its concentration in plasma. T1 / 2 acyclovir from breast milk is 2.8 hours, which is comparable to T1 / 2 from plasma.

In experimental studies, Valaciclovir did not have teratogenic effects in rats and rabbits. When administered orally, Valaciclovir did not cause fertility disorders in males and female rats.

Use in children

Clinical experience of use in children is absent.

Application in elderly patients

Older patients in the period of treatment need to increase the amount of fluid consumed.

special instructions

Patients with renal failure have an increased risk of developing neurological complications with valacyclovir.

Use with caution in patients with liver disease.

With great care appoint for any condition, accompanied by immunodeficiency, especially in HIV-infected patients. During the clinical trials with valaciclovir in high doses (8 g / day) for a long time, thrombocytopenic purpura and / or hemolytic uremic syndrome, rarely in fatal cases, in patients with clinically expressed forms of HIV infection, after transplantation bone marrow or kidney.

During the treatment of genital herpes, sexual intercourse should be avoided (the drug does not prevent transmission of infection).

The difference between Valaciclovir and Acyclovir

Valacyclovir is an L-valine ester of acyclovir, thus being a prodrug. After absorption into the blood, valaciclovir is almost completely converted into acyclovir under the influence of the hepatic enzyme valaciclovir hydrolase.

Drug Interactions

Acyclovir in unchanged form enters the urine as a result of active tubular secretion. Any drugs that are prescribed with it simultaneously and compete for this elimination mechanism can cause an increase in the concentration of acyclovir in the plasma. Cimetidine and drugs that block tubular secretion, when prescribed after taking Valaciclovir in a dose of 1 g, increase the acyclovir AUC and reduce its kidney clearance.

The pharmacokinetics of valacyclovir does not change with simultaneous admission with digoxin.

With the simultaneous administration of acyclovir and an inactive metabolite of mycophenolate mofetil (an immunosuppressant used in transplantation), there was an increase in the aUC of acyclovir and mycophenolate mofetil.

With the simultaneous use of valacyclovir with drugs that disrupt the function of the kidneys (including cyclosporine, tacrolimus), kidney function may worsen.

Analogues of the drug Valacyclovir

Structural analogs for the active substance:

• Vairova;
• Valavir;
• Valaciclovir Canon;
• Valaciclovir hydrochloride;
• Valacitek;
• Valwyr;
• Valmic;
• Walogard;
• Valtrex;
• Valtsikon;
• Wirdel.

Analogues on the curative effect (agents for the treatment of herpes simplex):

• Alpisarin ointment;
• Amiksin;
• Anaferon;
• Anaferon child;
• Antigerpes;
• Arbidol;
• Acyclovir;
• Vectavir;
• Virazole;
• Wirdel;
• Virolex;
• Virosept;
• Vitaherpavak;
• Viferon;
• Galavit;
• Gevisos;
• Gerpevir;
• Herpes;
• Herpferon;
• Groprinosin;
• Devirs;
• Zovirax;
• Isoprinosine;
• Immunomax;
• Kagocel;
• Kipferon;
• Lavomax;
• Lycopid;
• Lorinden C;
• Neovir;
• Panavir;
• Supperan;
• Famvir;
• Famciclovir;
• Fenistil Pencivir;
• Ferrovir;
• Cyclovax;
• Cyclovir;
• Cycloviral;
• Cycloferon;
• Epigenum sex;
• Erazaban;
• Ergoferon.

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