Indications
Chronic hepatitis B against the background of hepatitis B virus replication.
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Active ingredient: | |
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Dosage form: | |
Indications for use: |
Chronic hepatitis B against the background of hepatitis B virus replication.
Hypersensitivity to lamivudine or any other component of the drug, pregnancy (I trimester).
With caution:Â it should be used for renal failure, pancreatitis (including in the anamnesis), peripheral neuropathy, pregnancy (II-III trimester), lactation, in childhood (up to 2 years).
Active substance:
lamivudine 100 mg;
Auxiliary substances:
MCC;
sodium starch glycolate;
magnesium stearate;
hypromellose;
titanium dioxide;
macrogol 400;
polysorbate 80;
iron oxides yellow and red
Active ingredient:
lamivudine 100 mg;
Auxiliary substances:
MCC;
sodium starch glycolate;
magnesium stearate;
hypromellose;
titanium dioxide;
macrogol 400;
polysorbate 80;
iron oxides yellow and red
Zeffix is an antiviral agent.
It is highly active against the hepatitis B virus (HBV).
In both infected and uninfected cells, lamivudine is metabolized to lamivudine triphosphate, which is the active form of the drug. In vitro, the half-life of lamivudine triphosphate in hepatocytes is 17-19 hours.
Lamivudine triphosphate is a substrate for hepatitis B virus DNA polymerase. Inclusion of lamivudine triphosphate in the viral DNA chain and subsequent chain breakage block further formation of viral IDNA. Lamivudine is a weak inhibitor of mammalian α-and β-DNA polymerases.
Studies to determine the possible effect on mitochondrial structure, as well as on the content and function of DNA, lamivudine did not have significant toxic effects. Lamivudine has a very weak ability to reduce the content of mitochondrial DNA, is not included, as a rule, in the mitochondrial DNA chain, and does not inhibit the gamma polymerase of mitochondrial DNA.
Zeffix® has a pronounced antiviral activity in vivo and rapidly suppresses HBV replication after starting treatment.
Pharmacokinetics
Well absorbed from the gastrointestinal tract, bioavailability in adults after oral use is usually 80-85%. When taken orally in therapeutic doses (100 mg once a day)Â Cmax is reached in approximately 1 h and is 1.1-1.5 mcg / ml.
Food intake reducesCmax (by 47%) and lengthensTmax, without changing the overall degree of lamivudine absorption (calculated on the basis of AUC). When administered intravenously, the volume of distribution averages 1.3 l/kg.
In the therapeutic dose range, lamivudine has linear pharmacokinetics and binds to plasma proteins to a small extent. According to limited data, lamivudine penetrates into the central nervous system and into the cerebrospinal fluid (2-4 hours after oral use, the ratio of concentrations in the cerebrospinal fluid and serum is approximately 0.12).
It is slightly biotransformed in the liver. The systemic clearance of lamivudine is on average about 0.3 l / h / kg. T1/2 — about 5-7 hours. Most of lamivudine is excreted unchanged by the kidneys through glomerular filtration and active secretion (organic cation transport system). Renal clearance accounts for about 70% of lamivudine elimination.
Special patient groups
In patients with renal insufficiency, the elimination of lamivudine from the body slows down (in patients with Cl creatinine
Patients with hepatic insufficiency (not infected with HIV and HBV) are well tolerated by lamivudine. Impaired liver function does not affect the pharmacokinetics of lamivudine, unless combined with renal insufficiency.
In elderly patients, age-related decline in renal function does not significantly affect the elimination of lamivudine with a creatinine clearance above 50 ml/min.
In women in the late stages of pregnancy, the pharmacokinetics of lamivudine after oral use were similar to those in non-pregnant women.
The pharmacokinetics of lamivudine in children do not differ from those in adults, but the clearance of lamivudine, adjusted for body weight, is higher than in adults, which is expressed in a decrease in AUC. The highest clearance of lamivudine is in children aged 2 years and decreases by 12 years, when its values become similar to those in adults.
The recommended dose for children from 2 to 11 years of age is 2 mg / kg once a day (up to a maximum of 100 mg/day), which can provide comparable exposure to lamivudine with an adult dose (100 mg / day). Data on the pharmacokinetics of lamivudine in children under 2 years of age are limited.
Chronic hepatitis B against the background of hepatitis B virus replication.
Hypersensitivity to lamivudine or any other component of the drug, pregnancy (I trimester).
With caution: Â it should be used for renal failure, pancreatitis (including in the anamnesis), peripheral neuropathy, pregnancy (II-III trimester), lactation, in childhood (up to 2 years).
The most common side effects are general malaise and rapid fatigue, respiratory tract infections, headache, abdominal discomfort and pain, nausea, vomiting, and diarrhea.
The frequency of changes in laboratory parameters in patients with chronic hepatitis B is similar when using Zeffix® and placebo; the exception is a more frequent increase in ALT levels after completing Zeffix®therapy. However, there is no significant difference in the frequency of elevated ALT levels combined with increased bilirubin levels and/or signs of liver failure. It is not known whether these cases of hepatitis exacerbation are related to treatment with Zeffix® or to the course of chronic hepatitis itself.
Pancreatitis and peripheral neuropathy (or paresthesia) have been reported in patients with HIV infection, but the association of these complications with lamivudine therapy has not been proven. There was no significant difference in the incidence of these complications in the groups of patients with chronic hepatitis B taking Zeffix® and placebo.
Lactic acidosis, which was usually accompanied by severe hepatomegaly and fatty liver disease, has been reported in patients with HIV infection who received combination therapy with nucleoside analogues. There are isolated reports of the same side effects in patients with viral hepatitis B and hepatic insufficiency; however, there are no data confirming the association of these complications with Zeffix®.
The probability of metabolic interaction of lamivudine with other drugs is low due to limited metabolism, low degree of binding to plasma proteins and excretion of the drug mainly by the kidneys in unchanged form.
Consideration should be given to the possibility of interaction of lamivudine with other drugs, the main mechanism of elimination of which is active renal secretion using the organic cation transport system, for example with trimethoprim. Other drugs (for example, ranitidine, cimetidine) are only partially eliminated by this mechanism and do not interact with lamivudine.
Drugs that are mainly eliminated by active transport of organic anions or by glomerular filtration do not appear to have clinically significant interactions with lamivudine.
Simultaneous use of trimethoprim / sulfamethoxazole (co-trimoxazole) at a dose of 160 mg / 800 mg leads to an increase in lamivudine exposure by 40% due to interaction with trimethoprim. However, in the absence of renal failure, there is no need to reduce the dose of lamivudine. Lamivudine does not affect the pharmacokinetics of trimethoprim and sulfamethoxazole.
With simultaneous use of lamivudine and zidovudine, a moderate (28%) increase in peak plasma concentrations of zidovudine was observed, but the area under the “plasma concentration — time” curve did not change significantly. Zidovudine has no clinically significant effect on the pharmacokinetics of lamivudine.
No pharmacokinetic interaction of lamivudine with alpha-interferon was observed with the simultaneous use of these drugs. No clinically significant adverse interactions have been reported in patients treated concomitantly with Zeffix®and immunosuppressants (e. g. cyclosporin A); however, no specific studies have been conducted. Lamivudine may inhibit intracellular phosphorylation of zalcitabine. Therefore, concomitant use of lamivudine and zalcitabine is not recommended.
Inside, regardless of food intake.
Adults and children aged 12 years and older: Â 100 mg once a day.
Children from 2 to 11 years: 3 mg / kg once a day, but not more than 100 mg / day.
Children under 2 years of age: Â There is insufficient data to recommend dosages in this age group.
Symptoms: Â There were no specific symptoms of lamivudine overdose.
Gastric lavage, use of activated charcoal, monitoring of the patient’s condition and standard maintenance therapy are recommended.
Continuous hemodialysis may be used to remove lamivudine, but no specific studies have been conducted.
During treatment with Zeffix, the condition of patients should be regularly monitored by a doctor who has experience in the treatment of chronic hepatitis B.
Pills.
At a temperature not exceeding 30 °C
3 years
Lamivudine
By prescription
Tablets
Hepatitis
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