Specifications: In-house 

Composition
Each film-coated tablet contains lamivudine 100 mg and excipients q.s. (microcrystalline cellulose, pregelatinized starch, L-HPC, magnesium stearate, film coating excipient).

Dosage form
Film-coated tablets.

Presentation
Box of 2 blisters x 14 film-coated tablets.

Indications
VICTRON® is indicated to patients from 16 years of age with chronic viral hepatitis B associated with evidence of hepatitis B viral replication (HBV) and active liver inflammation, with one or more of the following conditions:
- Elevated serum alanine aminotransferase (ALT) more than or equal to 2 times of normal level.
- Liver cirrhosis.
- Decompensated liver disease.
- Biopsy-proven necro-inflammatory liver disease.
- Immunocompromised state.
- Liver transplant.

Contra-indications
Hypersensitivity to lamivudine.

Dosage and Administration
- Patients from 16 years of age:
  Recommended dose: 100 mg once daily.
- Renal impairment patients with creatinine clearance less than 50 mL/min: reduction of the dosage is recommended.
Lamivudine can be taken with or without food.
Optimal duration of lamivudine therapy has not been established, so this drug should be use under doctor’s instruction.
Treatment discontinuance may be considered in the following situation:
- Immunocompetent patients when HBeAg and/or HBsAg seroconversion confirmed.
- Female patients become pregnant during therapy.
- Patients show signs of intolerance to lamivudine on treatment.
- Treatment failed with lamivudine (based on doctor’s examination) e.g. when persistent return of serum ALT to pre-treatment value occurs or when the patient experiences deterioration in liver histology. 
Patient compliance should be monitored during lamivudine therapy.
If lamivudine is discontinued, patients should be periodically monitored for evidence of relapsed hepatitis.
Dose adjustment:
- Renal impairment: it is recommended that doses of lamivudine be adjusted in accordance with renal function as followed:

 - Hepatic impairment: Pharmacokinetic parameters of lamivudine are not significantly affected in case of hepatic dysfunction. Therefore, dose adjustment is not necessary unless accompanied by renal impairment.

Precautions
Patients should be monitored regularly during treatment by a physician experienced in treatment of chronic hepatitis B.
After the treatment of lamivudine is discontinued, some patients may experience clinical or laboratory evidence of relapsed hepatitis, which may have more severe consequences in patients with decompensated liver disease. Patients should be periodically monitored both clinically and by assessment of serum liver function test (for ALT and bilirubin levels) for at least 4 months for evidence of relapsed hepatitis. The doses of 150 mg of lamivudine, twice daily should be maintained for the treatment of patients who are co-infected with HIV and are currently receiving or plan to receive treatment with lamivudine alone or lamivudine and zidovudine concomitantly.
Data on maternal-foetal transmission of hepatitis B virus in pregnant women receiving treatment with lamivudine has not been established. The standard recommended procedures for hepatitis B virus immunization in infants should be followed.
Patients should be advised that therapy with lamivudine has not been proven to reduce the risk of transmission of hepatitis B virus to others and therefore, appropriate precautions should still be taken.
Safety and efficacy of lamivudine have not been established in pediatric patients under 2 years of age, patients dually infected with HBV and HCV, HIV or delta hepatitis.

Special warnings
- Lactic acidosis/ severe hepatomegaly with steatosis: Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination, including lamivudine and other antiretrovirals. A majority of these cases occurred in women. Obesity and prolonged nucleoside exposure may be risk factors. Most of these reports have described patients receiving nucleoside analogues for HIV infection, but some others reported lactic acidosis occurred in patients receiving lamivudine for treatment of hepatitis B. Particular caution should be exercised when lamivudine is administered to any patients with known risk factors of liver disease; however, care should also be taken to patients without risk factors. Discontinuance of treatment with lamivudine should be required in patients who develop clinical or laboratory finding suggestive of lactic acidosis or pronounced hepatotoxicity (which may induce hepatomegaly and steatosis even in the absence of marked transaminase elevations).
- Important differences between lamivudine-containing products, HIV testing, and risk of emergence of resistant HIV: The formulation and dosage of lamivudine in VICTRON film-coated tablet are not appropriate for patients dually infected with HBV and HIV. If lamivudine is indicated to these patients, a higher dose for HIV treatment should be administered as a part of an appropriate combination regimen, in addition, patients should also be informed about the drug information. Counseling and HIV testing should be offered to all patients before beginning and during lamivudine treatment. It is because the risk of rapid emergence of resistant HIV and the limitation of treatment options when lamivudine is prescribed to treat chronic hepatitis B in patient who has unrecognized or untreated HIV infection or acquired HIV infection during treatment.
- Post-treatment exacerbations of hepatitis: Clinical and laboratory evidences of exacerbations of hepatitis have occurred after discontinuance of lamivudine (these have been primarily detected by serum ALT elevations, in addition to the re-emergence of HBV DNA commonly observed after stopping treatment). Although most events appear to have been self-limited, fatalities have been reported in some cases. The causal relationship between the discontinuance of lamivudine and the post-treatment exacerbations of hepatitis is unknown. Patients should be strictly monitored with both clinical and laboratory follow-up for several months after the treatment ended. There is insufficient evidence to determine whether re-initiation of therapy alters the course of post-treatment exacerbations of hepatitis.
- Pancreatitis: Pancreatitis has been reported in patients receiving lamivudine, particularly in HIV-infected pediatric patients previously exposed with nucleoside.

Side effects
The most common adverse events were malaise and fatigue, respiratory tract infections, headache, abdominal discomfort and pain, nausea, vomiting and diarrhea.
Several serious adverse events reported with lamivudine (lactic acidosis and hepatomegaly with steatosis, post-treatment exacerbations of hepatitis B, pancreatitis, and emergence of mutant viruses associated with the reduction of drug susceptibility and of treatment response).

Overdose
Administration of lamivudine at very high dose in acute animal studies did not result in organ toxicity. Limited data are available on the consequence of ingestion of acute overdoses in humans. No fatalities occurred. No specific signs or symptoms have been identified following such overdose. 
If overdose occurs, the patients should be monitored, and standard supportive treatment applied as required. Since lamivudine is dialyzable, continuous haemodialysis could be conducted in the treatment of overdose.

Drug interactions
The likelihood of metabolic interactions is low due to limited metabolism and plasma protein binding and almost complete renal elimination of unchanged drug.
Lamivudine is predominantly eliminated by active organic cationic secretion. The possibility of interactions with other drugs administered concurrently should be considered, particularly when their main route of elimination is active renal secretion via the organic cationic transport system e.g. trimethoprim. Other drugs (e.g. ranitidine, cimetidine), which considered not interacting with lamivudine, are eliminated only in part by this mechanism.
Drugs predominantly excreted either via the active organic anionic pathway or by glomerular filtration are unlikely to yield clinically significant interactions with lamivudine.
Concomitantly administration of trimethoprim (TMP) 160 mg, sulphamethoxazole (SMX) 800 mg once daily increased lamivudine exposure (AUC) by 44%. Dosage changing of either drug is recommended. There is no information regarding the effect on lamivudine pharmacokinetics of higher doses of TMP or SMX such as those used to treat Pneumocystis carinii pneumonia. No available data regarding the potential interaction with other drugs that have renal clearance mechanisms similar to that of lamivudine.
Lamivudine and zalcitabine may inhibit the intracellular phosphorylation of one another. Therefore, use of lamivudine in combination with zalcitabine is not recommended.
Animal studies or in vitro data suggested the lack of interactions between lamivudine and a number of concomitantly administered drugs. Lamivudine was shown not to interact with the cytochrome P450. Interactions only occurred with ganciclovir (weakening of the anti-HIV activity) and trimethoprim.

Use in pregnancy and lactation
- Use in pregnancy
Reproduction studies have been performed in rats and rabbits at oral dose, no evidence of teratogenicity due to lamivudine was observed. Nevertheless, lamivudine should only be used during pregnancy if the potential benefits outweigh the risks. Patients who receiving lamivudine during pregnancy or being pregnant should immediately inform to the physician. 
- Use in lactation
Mothers who are receiving lamivudine should discontinue breast-feeding. 
Effects on the ability to drive and use machines
Study on investigation the effect of lamivudine on the ability to drive and to operate machines has not been established. Also, these detrimental effects would not be predicted from the pharmacology of the drug.

Pharmacology
Lamivudine is an anti-viral agent which is highly active against hepatitis B virus in all cell lines tested and in experimentally infected animals.
Lamivudine is metabolized by both infected and uninfected cells to the triphosphate (TP) derivative which is the active form of the parent compound. The intra-cellular half life of the triphosphate in hepatocyte is 17 - 19 hours in vitro. Lamivudine-TP acts as a substrate for the HBV viral polymerase. The formation of further viral DNA is blocked by incorporation of lamivudine-TP into the chain and subsequent chain termination.
Lamivudine-TP does not interfere with normal cellular desoxynucleotide metabolism. It is also only a weak inhibitor of mammalian DNA alpha and beta polymerases. Furthermore, lamivudine-TP has little effect on mammalian cell DNA content.
In assay relating to potential drug effects on mitochondrial structure and DNA content and function, lamivudine lacked appreciable toxic effects. It has a very low potential to decrease mitochondrial DNA content, is not permanently incorporated into mitochondrial DNA, and does not act as an inhibitor of mitochondrial DNA gamma polymerase.

Pharmacokinetics
- Absorption
Lamivudine is well absorbed from the gastrointestinal tract, and the bioavailability of oral dosage form in adults is normally between 80% and 85%. Following oral administration, the mean time (tmax) to maximal serum concentrations (Cmax) is about an hour. 
At therapeutic dose (i.e.100 mg once daily), Cmax is in the order of 1.1-1.5 mg/mL and stable level is 0.015 - 0.020 mg/mL.
Co-administration of lamivudine with food resulted in a delay of tmax and a lower Cmax (decreased by 47%). However, the extent (based on the AUC) of lamivudine absorbed was not influenced, therefore lamivudine can be administered with or without food.
- Distribution 
From intravenous studies the mean volume of distribution is 1.3 L/kg. Lamivudine exhibits linear pharmacokinetics over the therapeutic dose range and displays low plasma albumin binding.
Limited data shows lamivudine penetrates the central nervous system and present in the cerebro-spinal fluid (CSF). The mean ratio of CSF level to serum level after oral administration 2-4 hours was approximately 0.12.
- Metabolism 
Lamivudine is predominately renal excreted in unchanged form. The likelihood of metabolic drug interactions with lamivudine is low due to the small extent (5 - 10%) of hepatic metabolism and the low plasma protein binding.
- Elimination 
The mean systemic clearance of lamivudine is approximately 0.3 L/h/kg. The observed half-life of elimination is 5 to 7 hours. The majority of lamivudine is excreted unchanged in the urine via glomerular filtration and active secretion (organic cationic transport system). Renal clearance accounts for about 70% of lamivudine elimination.

Shelf-life
36 months.

Storage 
Store in a dry and cool place (<30 C). Keep out of reach of children.