X-vir 0.5mg tablets are used as anti-viral medicine, the safety and effectiveness of the X-vir 0.5mg has been established against chronic hepatitis B viral infection. X-vir 0.5mg contains an active compound known as Entecavir. X-vir 0.5mg is a classified as prototype for cyclopentane class of nucleoside or nucleotide long lasting hepatitis B anti-viral drug. Entecavir is coordinate with development of minimal resistance in long term therapy of nucleoside naïve patients.
X-vir INDICATED FOR
The critical points take into consideration, while starting the therapy with X-vir 0.5mg tablets;
Indication of X-vir 0.5mg is established by clinical trial data in nucleoside inhibitor-therapy naïve and lamivudine resistant patients with HBeAg positive and HBeAg negative HBV infection and compensated liver cirrhosis & decompensated cirrhosis.
X-vir 0.5mg is used in pediatric patients with 2 years of age or older, with treatment naïve, lamivudine resistant with HBeAg positive HBV infection & compensated liver cirrhosis.
X-vir 0.5mg tablets are used to treat chronic hepatitis B viral infection commonly in adolescent patients with the sign of viral multiplication and other information of lasting elevation of serum aminotransferase or active disease.
X-vir 0.5mg MECHANISM OF ACTION
X-vir 0.5mg enclose as Entecavir as an active component, a synthetic analogue of 2-deoxyguanosine has anti-viral activity against hepatitis B virus.
Entecavir is triggers in-vivo into 5-triphosphate metabolite which is an active form of Entecavir.
Consecutively, the active metabolite triphosphate form collides with natural substrate deoxyguanosine triphosphate dGTP for insertion into viral DNA. Thus, the inclusion of the activated triphosphate metabolite of Entecavir causes prohibition of reverse transcriptase enzyme.
RT is responsible for viral production and transcription, thus inhibition results as cell lysis.
X-vir 0.5mg tablet, after an oral administration it may undergo ADME properties. The peak plasma concentration time of X-vir 0.5mg is occurs within 0.5 & 1.5 hours. The steady state of X-vir 0.5mg is reaches after 6 to 10 days of single dose administration. X-vir 0.5mg Cmax value is 4.2ng/ml and trough plasma concentration are 0.3ng/ml
Oral administration of X-vir 0.5mg with high fat meal causes decreasing the absorption, depletes Cmax of 44 to 46%, decreases AUC of 18 to 20%.
The volume of distribution is exuberance of total body water; Entecavir is largely distributed into tissues. The binding of Entecavir with serum proteins occurs relatively 13%.
Entecavir should not be considering as cytochrome P450 enzymes substrate, inhibitor or inducers, which is adequately phosphorylated into an active triphosphate form.
X-vir 0.5mg tablets after metabolism get eliminated via kidneys, in an unchanged form with the range 62% to 73%. The plasma concentration of X-vir 0.5mg depletes in bi-exponential manner with the mean terminal half life period of relatively 128 to 148 hours and the phosphorylated metabolite half life is 15 hours.
X-vir 0.5mg DOSAGE AND ADMINISTRATION
The dosage recommendation of X-vir tablets are given below as follows;
In compensated liver disease
The usual dosage of X-vir tablet for this condition in adults is 0.5mg should be recommended as a single dose. History of hepatitis B viremia in patients: At the time of getting lamivudine or well-known lamivudine or telbivudine opposed substitutions like rtM204I/V with or without rtL180M, rtL80I/v, or rtV173L, in this situation the recommended dosage of X-vir 0.5mg is 1mg should be administered as a single dose.
In decompensated cirrhosis
In chronic hepatitis B viral infected patients, the prescribed dosage of X-vir is 1mg should be given orally as a single dose.
In pediatric patients
For therapy naïve patients
The recommended dosage of X-vir tablet is 0.5mg should be given as a single dose.
For lamivudine resistance
The prescribed dosage is 1mg of X-vir should be taken as a single dose.
For renal impairment patients
CrCl 50ml/min or greater: The recommended dosage is 0.5mg of X-vir given as a single dose CrCl 30 to less than 50ml/min: The recommended dosage is 0.5mg of X-vir given for every 48 hours CrCl 10ml/min to less than 30ml/min: The prescribed dosage is 0.5mg of X-vir should be given for every 72 hours. CrCl less than 10ml/min & hemodialysis, CAPD: The suggested dosage is 0.5mg of X-vir given for every 7 days.
In lamivudine resistant or decompensated cirrhosis
CrCl 50ml/min or greater: The recommended dosage is 1mg of X-vir 0.5mg given as a single dose CrCl 30 to less than 50ml/min: The recommended dosage is 0.5mg of X-vir given as a single dose or 1mg for every 48 hours. CrCl 10ml/min to less than 30ml/min: The prescribed dosage is 1mg of X-vir should be given for every 72 hours. CrCl less than 10ml/min & hemodialysis, CAPD: The suggested dosage is 1mg of X-vir given for every 7 days.
How to administer X-vir 0.5mg tablets
X-virtablet should be given for chronic hepatitis B viral infected patients, taken in an empty stomach i.e., partially 2 hours after a meal and 2 hours earlier the next meal.
The most common adverse reaction occurs during or after the treatment
• Severe aggravation of hepatitis B infection
• Lactic acidosis
• Hepatomegaly with steatosis
The common side effects like
Dyspepsia, Alopecia, Rash, Elevation of transaminase, Headache, Fatigue, Anaphylactic reactions, Dizziness, Diarrhea, Nausea, Vomiting, Somnolence, Insomnia, Hepatic failure, Gastrointestinal hemorrhage, Hepatocellular carcinoma
X-vir 0.5mg PRECAUTIONS
Some precautions should be taken while starting therapy with X-vir;
In severe acute aggravation of hepatitis B
This adverse may occur after discontinuation of anti-hepatitis B therapy. In this condition patient should be monitored frequently with liver functions and other laboratory follow ups. Continue the anti-hepatitis B therapy, if required.
In HBV/HIV-1 co infected patients
Entecavir has not assessed in HIV/HBV co infected patients who are not concurrently taking effective anti-retroviral therapy. X-vir 0.5mg tablet used for HBV infection in patients who are infected with HIV, produce resistant to HIV nucleoside reverse transcriptase inhibitors, not exist to treat. X-vir 0.5mg should not be suggested to HBV/HIV co infected patients, also not receiving HAART. To overcome this type of condition, patient should be examining with HIV antibody testing before the therapy.
In lactic acidosis & hepatomegaly with steatosis
This condition may occur due to the combination of nucleoside analog with anti-retroviral agents, this may happen mostly in women. The major fatal cases of this condition are obesity and extended nucleoside exposure. Lactic acidosis frequently occurs in decompensated liver cirrhosis patients, the only way to reduce this adverse is discontinuing the treatment with X-vir.