Valtrex - instructions for use, analogs, reviews and release forms (tablets 500 mg) of the drug for the treatment and prevention of oral and genital herpes, as well as cytomegalovirus infection in adults, children and pregnancy. Composition and alcohol

In this article, you can read the instructions for using the drug Valtrex. There are reviews of visitors to the site - consumers of this medication, as well as opinions of physicians specialists on the use of Valtrex 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. Valtrex analogs in the presence of existing structural analogs.Use for the treatment of oral and genital herpes, as well as cytomegalovirus infection in adults, children, as well as during pregnancy and lactation. Composition and interaction of the drug with alcohol.

Valtrex - antiviral drug. In the human body valacyclovir is rapidly and completely converted into Acyclovir under the influence of valacyclovirhydrolase.

Acyclovir has a specific inhibitory activity against Herpes simplex virus types 1 and 2, Varicella zoster and Epstein-Barr, cytomegalovirus and human herpesvirus type 6. Acyclovir inhibits the synthesis of viral DNA immediately after phosphorylation and conversion into active form of acyclovir triphosphate. The first stage of phosphorylation occurs with the participation of virus-specific enzymes. For viruses Herpes simplex, Varicella zoster and Epstein-Barr, such an enzyme is viral thymidine kinase, which is present in virus-infected cells. Partial selectivity of phosphorylation persists in the cytomegalovirus and is mediated through the product of the UL 97 phosphotransferase gene. Activation of acyclovir with a specific viral enzyme greatly explains its selectivity.

The process of phosphorylation of acyclovir (conversion from mono- to triphosphate) is completed by cellular kinases. Acyclovir triphosphate competitively inhibits viral DNA polymerase and, being an analogue of the nucleoside, is inserted into the viral DNA, which leads to obligatory (complete) chain rupture, discontinuation of DNA synthesis and, consequently, to blocking the replication of the virus.

In patients with preserved immunity, Herpes simplex and Varicella zoster viruses with a low sensitivity to valacyclovir are extremely rare (less than 0.1%), but can sometimes be found in patients with severe impairment of immunity, for example, with bone marrow transplant, in chemotherapy for malignant neoplasms and in HIV-infected people.

Resistance is caused by a deficiency of thymidine kinase of the virus, which leads to excessive spread of the virus in the host organism. Sometimes a decrease in sensitivity to acyclovir is due to the appearance of strains of the virus with a violation of the structure of the viral thymidine kinase or DNA polymerase. The virulence of these varieties of the virus resembles that of its wild strain.

Composition

Valaciclovir hydrochloride (Valaciclovir) + excipients.

Pharmacokinetics

After oral administration, Valtrex is well absorbed from the digestive tract, quickly and almost completely converted into acyclovir and valine. This transformation is catalyzed by the enzyme valacyclovirhydrolase, isolated from the human liver. The degree of binding of acyclovir 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

• treatment of herpes zoster caused by the virus Varicella zoster (accelerates the disappearance of pain, reduces its duration and the percentage of patients with pain, including acute and postherpetic neuralgia);
• treatment of skin and mucous membrane infections caused by herpes simplex virus type 1 and 2 (including newly diagnosed and recurrent genital herpes);
• treatment of labial herpes (labial fever);
• Valtrex is able to prevent the formation of lesions, if it is taken at the appearance of the first symptoms of recurrence of herpes simplex;
• prophylaxis (suppression) of recurrences of diseases of the skin and mucous membranes caused by the Herpes simplex virus type 1 and 2, including genital herpes;
• Valtrex can reduce the infection of genital herpes with a healthy partner, if taken as a suppressive therapy in combination with safe sex;
• prevention of cytomegalovirus infection arising from organ transplantation (reduces the severity of acute graft rejection in patients with kidney transplants, the development of opportunistic infections and other viral infections caused by herpes simplex virus and Varicella zoster).

Forms of release

The tablets covered with a cover of 500 mg.

Instructions for use and dosage

To treat herpes zoster, adults are prescribed 1 g 3 times a day for 7 days.

To treat diseases caused by the herpes simplex virus (Herpes simplex), adults are prescribed Valtrex 500 mg twice a day. In case of relapse, treatment should be given within 3 or 5 days. In more severe primary cases, treatment should be started as early as possible, and its duration should be increased from 5 to 10 days. When relapses of the disease is optimal, Valtrex is prescribed in the prodromal period or immediately after the appearance of the first symptoms of the disease.

As an alternative for the treatment of labial herpes (lipid fever), Valtrex is effectively administered at a dose of 2 g 2 times for 1 day. The second dose should be taken after approximately 12 hours (but not earlier than 6 hours) after taking the first dose. With this dosage regimen, the duration of treatment should not exceed 1 day, as it does not provide additional clinical benefits. Therapy should be started when the earliest symptoms of a labial fever occur (ie, tingling, itching, burning).

For the prevention (suppression) of recurrences of infections caused by the Herpes simplex virus, adults with normal immunity parameters are prescribed at a dose of 500 mg once a day. Adults with immunodeficiency recommended to appoint 500 mg 2 times a day.

The duration of treatment is 4-12 months.

To prevent infection of genital herpes with a healthy partner in heterosexual adult patients with preserved immunity and with the number of exacerbations up to 9 per year, Valtrex should be prescribed 500 mg once a day. for a year or more every day with regular sexual intercourse, with irregular sexual intercourse, Valtrex should be taken 3 days before the alleged sexual contact.

Data on the prevention of infection in other populations of patients are absent.

For the prevention of cytomegalovirus infection in adults and adolescents over 12 years of age, the recommended dose is 2 g 4 times per day. The drug is prescribed as soon as possible after the transplantation. The dose should be reduced depending on the QC. The course duration is 90 days, but can be increased in patients with a high risk of infection.

Side effect

• headache;
• nausea, vomiting;
• anaphylaxis;
• dizziness;
• confusion of consciousness;
• hallucinations;
• decreased mental abilities;
• excitation;
• tremor;
• psychotic symptoms;
• convulsions;
• encephalopathy;
• coma;
• dyspnea;
• feeling of discomfort in the abdomen;
• diarrhea;
• leukopenia (mainly observed in patients with reduced immunity), thrombocytopenia;
• rash;
• manifestations of photosensitivity;
• itching;
• hives;
• angioedema;
• impaired renal function;
• acute renal insufficiency;
• renal colic (may be associated with impaired renal function).

Contraindications

• increased sensitivity to valaciclovir, acyclovir and any other component included in the preparation.

Application in pregnancy and lactation

There are limited data on the use of Valtrex in pregnancy. Valtrex is used only in cases where the potential benefit to the mother exceeds the possible risk to the fetus.

Registered data on the outcome of pregnancy in women taking Valtrex or Zovirax (acyclovir is an active metabolite of valaciclovir) did not show an increase in the number of birth defects in their children compared to the general population. Since a small number of women taking Valaciclovir during pregnancy are included in the register, it is impossible to make reliable and definite conclusions about the safety of valaciclovir during pregnancy.

Acyclovir, the main metabolite of valacyclovir, is excreted in breast milk. When a mother valacyclovir is taken inside at a dose of 500 mg twice a day, the child will undergo the same effect of acyclovir as if taking it inside at a dose of about 0.61 mg / kg per day. Valacyclovir in unchanged form was not detected in the plasma of the mother, breast milk or in the baby's urine.

Acyclovir, as a metabolite of the drug Valtrex, is biotransformed by the action of alcohol and aldehyde dehydrogenase and, to a lesser extent, aldehyde oxidase into inactive metabolites.This can cause competition from ethanol (alcohol) for these enzymes, which in turn can lead to increased toxicity of the effects on the body of alcohol.

With this in mind, Valtrex should be cautiously prescribed to the mother during lactation (breastfeeding). However, intravenous administration of zovirax at a dose of 30 mg / kg per day is used in neonates for the treatment of diseases caused by the herpes simplex virus.

In experimental studies, valaciclovir did not have teratogenic effects in rats and rabbits. The administration of acyclovir in conventional tests of teratogenicity did not cause teratogenic effects in rats and rabbits. In additional studies in rats, fetal abnormalities were detected with subcutaneous administration of the drug in doses that caused an increase in the plasma concentration of acyclovir to 100 μg / ml and toxic effects in the mother.

When administered orally, valaciclovir did not cause fertility disorders in males and female rats.

Use in children

The experience of clinical use of Valtrex in children is small.

65 children aged 12 to 18 years took the tablet form of valacyclovir inside within 1-2 days about herpes.The frequency, nature and intensity of unwanted adverse reactions (including deviations in laboratory parameters) were similar to those in a group of adult patients.

special instructions

Patients with a risk of dehydration, especially elderly patients, during treatment with Valtrex, it is necessary to ensure adequate hydration of the body.

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

When violations of liver function in patients with mild to moderate liver cirrhosis (synthetic liver function preserved) correction of Valtrex dosage is not required. In the study of pharmacokinetics in patients with severe cirrhosis of the liver (with a violation of the synthetic function of the liver and the presence of shunts between the portal system and the common vascular bed), there was also no evidence of a need for correction of the dosing regimen; However, the clinical experience of using Valtrex in this category of patients is organic.

There is no data on the use of Valtrex in high doses (4 g per day or more) in patients with liver disease, so caution should be given to the drug in high doses of this category of patients.

Older patients are not required to adjust the dose, except in cases of significant renal dysfunction. It is necessary to maintain an adequate water-electrolyte balance.

Special studies to study the action of Valtrex in patients with liver transplant were not carried out. However, it has been shown that the prophylactic administration of acyclovir in high doses reduces the cytomegalovirus infection.

Suppressive therapy Valtrex reduces the risk of transmission of genital herpes, but does not exclude it completely and does not lead to complete cure. During Valtrex therapy, the patient must take measures to ensure the safety of the partner during sexual intercourse.

Influence on the ability to drive vehicles and work with mechanisms

Special precautions are not required.

Drug Interactions

Clinically significant interaction of Valtrex with other drugs has not been established.

Acyclovir is excreted in the urine mostly unchanged as a result of active tubular secretion. After taking Valtrex in a dose of 1 g of cimetidine and probenecid, which block tubular secretion, increase the AUC of acyclovir and reduce its renal clearance.However, correction of Valtrex dosage is not required in this case; Acyclovir has a wide therapeutic index.

It is necessary to use Valtrex at higher doses (4 g per day) with caution at the same time as drugs that compete with acyclovir for the path of elimination, there is a risk of an increase in plasma levels of one or both drugs or their metabolites. There was an increase in the AUC of acyclovir and the inactive metabolite of mycophenolate mofetil (an immunosuppressant used in transplantation) with the simultaneous use of these drugs.

Care should be taken when Valtrex is combined in a high dose (4 g per day or more) with drugs that disrupt the function of the kidneys (including cyclosporin, tacrolimus).

Analogues of Valtrex drug

Structural analogs for the active substance:

• Vairova;
• Valaciclovir;
• Valaciclovir hydrochloride;
• Vatsireks.

Analogues on the therapeutic effect (means for treating herpes):

• Amiksin;
• Anaferon;
• Anaferon child;
• Antigerpes;
• Lakry Antioxidant;
• Arbidol;
• Acyclovir;
• Vectavir;
• Vero Acyclovir;
• Virazole;
• Virolex;
• Virosept;
• Viferon;
• Galavit;
• Gevisos;
• Gerpevir;
• Herpferon;
• Herpes;
• Groprinosin;
• Devirs;
• Zovirax;
• Isoprinosine;
• Immunomax;
• Kagocel;
• Kipferon;
• Lavomax;
• Lysavir;
• Lycopid;
• Lomagherpan;
• Lorinden C;
• Sodium nucleate;
• Neovir;
• Panavir;
• Supperan;
• Famvir;
• Fenistil Pencivir;
• Ferrovir;
• Cyclovax;
• Cyclovir;
• Cycloviral SEDIKO;
• Cytivir;
• Epigenum sex;
• Ergoferon.

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