Description
Release form
Tablets.
Packing
42 pcs.
Pharmacological action
Valtrex has an antiviral effect.
After phosphorylation with the formation of active triphosphate, it competitively inhibits viral DNA polymerase, blocks DNA synthesis and viral replication.
Indications
Herpes zoster (including pain in acute and postherpetic neuralgia)
Infections of the skin and mucous membranes caused by the herpes simplex virus (including the first detected and recurrent genital herpes)
Herpes simplex prophylaxis.
Contraindications
Hypersensitivity (including to acyclovir).
Pregnancy and lactation
Limited data are available on the use of Valtrex in pregnancy. Valtrex is used only in cases where the potential benefit to the mother outweighs the potential risk to the fetus.
Pregnancy outcome register data for women taking Valtrex or Zovirax (acyclovir is an active metabolite of valacyclovir), did not show an increase in the number of birth defects in their children compared to the general population. Since the register includes a small number of women who took valaciclovir during pregnancy, it is impossible to draw reliable and definite conclusions about the safety of using valaciclovir during pregnancy.
The main metabolite of valaciclovir is acyclovir, which is excreted in breast milk in concentrations 0.6 4.1 times higher than its plasma concentration. T1 / 2 of acyclovir from breast milk is 2.8 hours, which is comparable to T1 / 2 from blood plasma. Given this, caution should be exercised when prescribing Valtrex during lactation (breastfeeding).
In experimental studies, valaciclovir did not exert teratogenic effects in rats and rabbits. When taken orally, valaciclovir did not cause fertility disorders in male and female rats.
Special instructions
In patients with normal immunity, viruses with reduced sensitivity are extremely rare relatively more often these viruses are found in people with severe immunodeficiency (in recipients of internal organs or bone marrow of patients receiving chemotherapy for malignant tumors infected with HIV).
Reduced sensitivity of viruses to the drug is due to phenotypic deficiency of thymidine kinase in cells infected with the virus, while the virulence of such viruses is close to that of wild viruses. Elderly patients during the treatment period need to increase the amount of fluid consumed. In the absence of pronounced renal dysfunction, correction of the dosage regimen is not required. The experience of using the drug in children is insufficient.
In the treatment of genital herpes, sexual contact should be avoided, as the drug does not protect against transmission.
Taking the drug in high doses for a long time in conditions accompanied by severe immunodeficiency (bone marrow transplantation, clinically expressed forms of HIV infection, kidney transplantation), led to the development of thrombocytopenic purpura and hemoliticouremic syndrome, up to a fatal outcome.
Composition
1 tab. contains valaciclovir (L-valine ester of acyclovir) 500 mg.
Dosage and Administration
Inside. Adults with herpes zoster – 1000 mg 3 times a day (7 days).
With herpes simplex – 500 mg 2 times a day for relapses – for 5 days.
During the first episode with a severe course, the duration of treatment can be increased to 10 days.
Side effects
Nausea, vomiting, gastralgia, decreased appetite, dizziness, headache, excessive fatigue, renal failure, microangiopathy, hemolytic anemia, thrombocytopenia (in patients with severe immunodeficiency, who received high doses of valaciclovir (8 g / day) and for a long time), increased AST activity.
Drug Interactions
Cimetidine and tubular secretion blockers reduce the effect (decrease the speed, but not the fullness of conversion to acyclovir).
Nephrotoxic drugs increase the risk of nephrotoxicity and central nervous system disorders.
overdose
Symptoms: sediment deposition in renal tubules.
Treatment: hemodialysis (with acute renal failure and anuria).
Storage conditions
At a temperature not exceeding 30 ° C
Shelf life
3 years.
Active ingredient
Valaciclovir
Terms and conditions
prescription
dosage form
tablets
Indications Indications
Genital Herpes, Herpes Zoster, Herpes
GlaxoSmithKline, UK
