Valtsikon pills film coated 500mg N10
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Active ingredients
Valaciclovir
Release form
Pills
Composition
1 tablet contains: Active substance: valaciclovir hydrochloride - 556.00 mg (in terms of valaciclovir 500.00 mg). Excipients: microcrystalline cellulose - 95.00 mg, hyprolose (hydroxypropylcellulose) - 14.00 mg, crospovidone - 28.00 mg, magnesium stearate - 7.00 mg. Film coating: [hypromellose - 10.50 mg, hyprolosis (hydroxypropylcellulose) - 4.07 mg, talc - 4.12 mg, titanium dioxide - 2.31 mg] or [dry mix for film coating - white, containing hypromellose (50 %), hydroxypropylcellulose (19.4%), talc (19.6%), titanium dioxide (11%)] - 21.00 mg.
Pharmacological effect
Valaciclovir is a nucleoside inhibitor of the DNA polymerase of herpes viruses. Blocks viral DNA synthesis and virus replication. In humans, valaciclovir is completely converted to acyclovir and L-valine. In vitro acyclovir has a specific inhibitory activity against herpes simplex viruses (HSV) 1.2 types (Herpes simplex 1.2 types), varicella zoster virus and herpes zoster (Varzella zoster virus), cytomegalovirus (CMV) , Epstein-Barr virus (EBV) and human herpes virus type 6. Acyclovir inhibits the synthesis of viral DNA immediately after phosphorylation and conversion to the active form of acyclovir triphosphate. The first stage of phosphorylation occurs with the participation of virus-specific enzymes. For HSV, VZV and EBV viruses, this enzyme is viral thymidine kinase, which is present in the cells affected by the virus. Partial selectivity of phosphorylation is retained in cytomegalovirus and is mediated through the gene product of the phosphotransferase UL 97. Activation of acyclovir by a specific viral enzyme largely explains its selectivity. The process of phosphorylation of acyclovir (conversion from mono to triphosphate) is completed by cellular kinases. Acyclovirphosphate competitively inhibits viral DNA polymerase and, being an analogue of a nucleoside, is incorporated into viral DNA, which leads to an obligatory breaking of the chain, termination of DNA synthesis and, therefore, blocking viral replication. In patients with preserved immunity, HSV and VZV viruses with decreased sensitivity to valacyclovir are extremely rare (less than 0.1%), but can sometimes be found in patients with severe immunity disorders, for example, with a bone marrow transplant, in those who receive chemotherapy for malignant neoplasms and in HIV-infected.Resistance is caused by a deficiency in the thymidine kinase of the virus, which leads to an excessive spread of the virus in the host. Sometimes the decrease in sensitivity to acyclovir is due to the appearance of virus strains with a violation of the structure of viral thymidine kinase or DNA polymerase. The virulence of these varieties of virus resembles that of its wild strain.
Pharmacokinetics
Absorption After oral administration, valaciclovir is well absorbed from the gastrointestinal tract, quickly and almost completely converted into acyclovir and valine. This transformation is catalyzed by a liver enzyme - valacyclovirhydrolase. After a single dose of 250-2000 mg of valaciclovir, the average maximum concentration (Cmax) of acyclovir in the blood plasma of healthy volunteers with normal renal function is on average 10-37 mcmol / l (2.2-8.3 μg / ml), and the average time reach a maximum concentration of 1-2 hours. When taking valaciclovir in a dose of 1000 mg, the acyclovir bioavailability is 54% and does not depend on food intake. Cmax of valaciclovir in the blood plasma is only 4% of the concentration of acyclovir and is achieved on average 30-100 minutes after taking the drug; after 3 h, the Cmax level remains the same or decreases. Valacyclovir and acyclovir have similar pharmacokinetic parameters after oral administration. Distribution Communication with valaciclovir proteins - 13-18%, acyclovir - 9-33%. Acyclovir is well distributed in tissues and body fluids, including the brain, kidneys, lungs, liver, aqueous humor, tear fluid, intestines, muscles, spleen, uterus, mucous membrane and vaginal secretions, semen, amniotic fluid, cerebrospinal fluid (50% of plasma concentrations), fluid herpetic vesicles. The highest concentrations are found in the kidneys, liver and intestines. Penetrates through the placenta and into breast milk. Withdrawal Valaciclovir 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 excreted unchanged. The half-life (T1⁄2) of valaciclovir is less than 30 minutes, acyclovir - 2.5-3.3 hours. In elderly patients (65-83 years), T1 Т2 acyclovir is 3.3-3.7 hours, and in patients with end-stage renal disease - about 14 h.The pharmacokinetics of valaciclovir and acyclovir are not significantly impaired in patients infected with HSV and VZV viruses. In HIV-infected patients, the pharmacokinetic parameters of acyclovir after oral administration of valaciclovir at a dose of 1000 mg and 2000 mg are comparable to those observed in healthy volunteers. In recipients of organ transplants receiving valaciclovir at a dose of 2000 mg 4 times / day, Cmax of acyclovir is equal to or greater than that of healthy volunteers who received the same dose of the drug, and the daily area under the pharmacokinetic curve (AUC) was significantly higher. In the late stages of pregnancy, the stable daily indicator of the area under the pharmacokinetic curve after taking 1000 mg of valaciclovir was more than 2 times greater than that when taking acyclovir at a dose of 1200 mg per day.
Indications
Adults: - treatment of herpes zoster (Herpes zoster) (the drug helps relieve pain, reduces its duration and the percentage of patients with pain caused by shingles, including acute and postherpetic neuralgia); - treatment of infections of the skin and mucous membranes caused by the Herpes simplex virus 1.2 type, including the first identified and recurrent genital herpes (Herpes genitalis), and also labial herpes (Herpes labialis); - prevention (suppression) of recurrences of infections of the skin and mucous membranes caused by the Herpes simplex virus 1.2 type, including genital herpes; - prevention of transmission of the virus of genital herpes to a healthy partner when using the drug as a suppressive therapy in combination with safe sex; Adults and children aged 12 years and older: - Prevention of cytomegalovirus (CMV) infection, as well as acute transplant rejection reactions (in patients with kidney transplants), opportunistic infections and other herpes viral infections (HSV, VVZ) after organ transplantation.
Contraindications
Hypersensitivity to valacyclovir, acyclovir, and any other component of the drug; HIV infection when the content of CD4 + lymphocytes is less than 100 in 1 μl; children's age (up to 12 years for the prevention of cytomegalovirus infection after transplantation, up to 18 years - for other indications).
Precautionary measures
Hepatic / renal failure, advanced age, hypohydration, simultaneous administration of nephrotoxic drugs, pregnancy, lactation, clinically expressed forms of HIV infection in patients.
Use during pregnancy and lactation
There are limited data on the use of valaciclovir during pregnancy. Valaciclovir is used only in cases where the potential benefit to the mother outweighs the possible risk to the fetus. Registered data on the outcome of pregnancy in women who took valacyclovir or acyclovir (the 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, there can be no reliable and definite conclusions about the safety of valaciclovir during pregnancy. Acyclovir, the main metabolite of valaciclovir, is excreted in breast milk. After taking valacyclovir orally at a dose of 500 mg, Cmax of acyclovir in breast milk 0.5-2.3 times (on average 1.4 times) exceeded the corresponding concentrations of acyclovir in the mother's blood plasma. The average concentration of acyclovir in breast milk was 2.24 μg / ml (9.95 μmol / l). When a mother takes valaciclovir orally at a dose of 500 mg 2 times / day, the child will be exposed to the same effect of acyclovir as when taking orally acyclovir at a dose of about 0.61 mg / kg / day.
Dosage and administration
Inside, regardless of the meal, drinking water. Treatment of shingles (Herpes zoster) Adults: The recommended dose is 1000 mg 3 times a day for 7 days. Treatment of infections caused by HSV. Adults: The recommended dose for treating an episode is 500 mg 2 times a day for 5 days. In more severe cases, the debut of the disease should begin as early as possible, and its duration can be increased from 5 to 10 days. In case of recurrence, treatment should last 3 or 5 days. When recurrent HSV is considered ideal, the appointment of valacyclovir in the prodromal period or immediately after the onset of the first symptoms of the disease. As an alternative for treating herpes simplex, it is effective to administer valaciclovir at a dose of 2 g twice a day. The second dose should be taken approximately 12 hours (but not earlier than 6 hours) after taking the first dose. When using this dosing regimen, the duration of treatment is 1 day. Therapy should be started when the earliest symptoms of cold sores appear (ietingling, itching, burning). Prevention (suppression) of recurrent infections caused by HSV Adults: In immunocompromised patients, the recommended dose is 500 mg once a day. In patients with immunodeficiency, the recommended dose is 500 mg 2 times a day. Prevention of the transmission of genital herpes to a healthy partner. Infected immunocompetent persons with relapses no more than 9 times a year the recommended dose of valacyclovir is 500 mg once a day for a year or more each day. Data on the prevention of infection in other populations of patients are not available. Prevention of cytomegalovirus (CMV) infection after transplantation Adults and adolescents aged 12 years and older: The recommended dose is 2 g 4 times a day, given as early as possible after transplantation. The dose should be reduced depending on the clearance of creatinine. The duration of treatment is 90 days, but in patients at high risk, treatment may be extended. Special groups of patients Patients with impaired renal function Treatment of shingles and infections caused by HSV, prevention (suppression) of recurrent infections caused by HSV, prevention of transmission of genital herpes to a healthy partner Table 1). In such patients, it is necessary to maintain adequate hydration. Experience with the use of valaciclovir in children with creatinine clearance values less than 50 ml / min / 1.73 m2 no. Patients on hemodialysis are advised to use valacyclovir immediately after the end of the hemodialysis session in the same dose as patients with creatinine clearance less than 15 ml / min. Prevention of cytomegalovirus (CMV) infection after transplantation The mode of administration of valaciclovir in patients with impaired renal function should be set in accordance with Table 2. Table 2 Creatinine clearance, ml / min , 5 g 4 times a day from 25 to less than 50 1.5 g 3 times a day from 10 to less than 25 1.5 g 2 times a day less than 10 or dialysis * 1.5 g 1 time a day * For patients on hemodialysis, valaciclovir should be administered after the end of the hemodialysis session. It is often necessary to determine creatinine clearance, especially at a time when kidney function changes rapidly, for example, immediately after transplantation or transplant engraftment, and the dose of valacyclovir is adjusted in accordance with creatinine clearance.Patients with impaired liver function In adult patients with impaired liver function of mild to moderate severity with an intact synthetic function, dose adjustment of valaciclovir is not required. Pharmacokinetic data in adult patients with severely impaired liver function (decompensated cirrhosis), with impaired synthetic liver function and the presence of porto-caval anastomoses also do not indicate the need to adjust the dose of valaciclovir, however, clinical experience with this pathology is limited. Children under the age of 12 There is no data on the use of the drug Valcicon in children. Elderly patients Dose adjustment is not required except for a significant impaired renal function. It is necessary to maintain an adequate water-electrolyte balance.
Side effects
From the side of the central nervous system: headache, dizziness, psychotic symptoms, agitation, mental decline, ataxia, coma, confusion or depression of consciousness, dysarthria, encephalopathy, mania, hallucinations, convulsions, tremors. These reactions are reversible and are usually observed in patients with impaired renal function or on the background of other predisposing conditions. In patients with a transplanted organ, receiving valaciclovir in high doses (8 g / day) for the prevention of cytomegalovirus infection, neurological reactions develop more often than when taken in lower doses. On the part of the respiratory system: dyspnea. On the part of the digestive system: nausea, abdominal discomfort, vomiting, diarrhea, reversible functional liver function tests (increased activity of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase), which are sometimes regarded as manifestations of hepatitis. On the part of the hematopoietic system: leukopenia (mainly observed in patients with reduced immunity), thrombocytopenia, anemia, thrombotic thrombocytopenic purpura. On the part of the skin: erythema multiforme, rash, photosensitivity, alopecia. Allergic reactions: itching, urticaria, angioedema, anaphylaxis. On the part of the urinary system: pain in the projection of the kidneys, renal dysfunction, including acute renal failure, renal colic.Renal colic may be associated with impaired renal function. From the senses: visual impairment. Laboratory indicators: reduction of hemoglobin, hypercreatininemia. Other: dysmenorrhea, nasopharyngitis, respiratory tract infections, high blood pressure, tachycardia, fatigue; in patients with severe impaired immunity, especially in adult patients with an advanced stage of HIV infection, receiving valaciclovir in high doses (8 g / day daily) for a long time, there have been cases of renal failure, microangiopathic hemolytic anemia and thrombocytopenia (sometimes in combination ). Similar adverse reactions were noted in patients with the same diseases, but not receiving valacyclovir.
Overdose
Symptoms: With an overdose of valaciclovir, acute renal failure and the development of neurological symptoms, including confusion, hallucinations, agitation, depression of consciousness, and to whom, nausea and vomiting are also noted. To prevent overdose, caution should be exercised when using the drug. Many cases of overdose have been associated with the use of the drug for the treatment of patients with impaired renal function and elderly patients, due to non-compliance with the dosing regimen (re-received doses of valacyclovir that exceed the recommended). Treatment. Patients should be carefully monitored for the timely diagnosis of toxic manifestations. Hemodialysis significantly accelerates the excretion of acyclovir from blood plasma and can be considered the best way to treat in case of symptomatic overdose.
Interaction with other drugs
Cimetidine and tubular secretion blockers reduce the effect (reduce the rate, but not the full conversion into acyclovir). Correction of the dosing regimen in individuals with normal creatinine clearance is not required. Nephrotoxic drugs increase the risk of kidney damage. Care must be taken (to observe the change in renal function) with the combination of the drug Valcicon in higher doses (4 g per day and more) with drugs that affect other kidney functions (for example: cyclosporine, tacrolimus).Acyclovir is excreted by the kidneys, mostly unchanged, through active renal secretion. The combined use of drugs with this mechanism of elimination may lead to an increase in plasma acyclovir concentration. After administration of the drug Valcicon in a dose of 1000 mg, cimetidine and probenecid, which are eliminated in the same way as valaciclovir, increase the AUC value of acyclovir and thus reduce its renal clearance. Due to the wide therapeutic index of acyclovir, dose adjustment of the drug Valcicon is not required in this case. Care must be taken in the case of simultaneous use of valaciclovir at higher doses (4 g per day and above) and drugs that compete with acyclovir for the elimination path, since there is a potential threat of an increase in plasma levels of one or both drugs or their metabolites. An increase in the AUC of acyclovir and the inactive metabolite of mycophenolate mofetil was noted with simultaneous use of these drugs. The pharmacokinetics of valaciclovir do not change when taken simultaneously with digoxin, aluminum / magnesium-containing antacids, thiazide diuretics.
special instructions
In patients at risk of dehydration, especially in elderly patients, it is necessary to ensure adequate fluid replenishment during the treatment period. Since acyclovir is excreted by the kidneys, the dose of the drug Valcicon should be adjusted depending on the degree of impaired renal function. In patients with renal failure, there is an increased risk of developing neurological complications, such patients should be carefully monitored. As a rule, these reactions are reversible and disappear after discontinuation of the drug. In patients with chronic renal failure (CRF), it is often recommended to determine creatinine clearance, especially at a time when kidney function changes rapidly (in particular, immediately after transplantation or transplant engraftment), while the dose of valaciclovir is adjusted in accordance with creatinine clearance. There are no data on the use of valaciclovir in high doses (4 g or more per day) in patients with liver disease, so high doses of the drug Valcicon should be given to them with caution.Suppressive therapy with valacyclovir reduces the risk of transmitting genital herpes, but does not exclude the risk of infection and does not lead to complete cure. Therapy with Valcicon is recommended in combination with safe sex. 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 hemolytic uremic syndrome, up to a fatal outcome. If the side effects of the central nervous system (including agitations, hallucinations, confusion, delirium, seizures and encephalopathy) occur, the drug is canceled.