Valcivir 500mg (Valacyclovir)
Valcivir 500mg includes an active composition like valacyclovir which is pharmacologically classify as nucleoside analogue of viral DNA polymerase prohibitor.
Valcivir 500mg which belongs to synthetically classified as nucleoside analogue. Valcivir 500mg is usually present as prodrug which gets changed into an active molecule known as acyclovir.
The major indication of valacyclovir is used in the condition like;
Herpes simplex & herpes zoster
Valcivir 500mg is mostly indicated for the treatment of cold sores by Herpes Labialis. Valcivir 500mg have capability to started after the advancement of clinical signs of cold sore has not been evaluated. Valcivir 500mg is likewise determined in the condition like starting scene of genital herpes in immune capable grown -ups. Valcivir 500mg is also indicated in the treatment of relapsed episodes of genital herpes in immuno competent episodes. Valcivir 500mg is exhibit for cutting edge suppressive therapy of repetitive scenes of genital herpes in immuno skillful and HIV-1 contaminated grown-ups. Valcivir 500mg is also used for the contraction of transmission of genital herpes in immuno competent adults. Valcivir 500mg is indicated in the treatment of herpes zoster in immuno competent adults.
In pediatric patients, Valcivir 500mg is includes in the therapy of cold sores with the age of greater or equal to 12 years. Valcivir 500mg is also indicated for the therapy of chicken pox in immuno competent pediatric patients with age of 2 to less than 18 years
MECHANISM OF ACTION
Valacyclovir which represented as a prodrug that will go through phosphorylation by using viral thymidine kinase enzyme for changing of acyclovir triphosphate, an active metabolite. This active molecule is included in the prevention of herpes viral DNA replication by competitive inhibition of viral DNA polymerase. After injected of this metabolite into the virus &causes terminate of the developing viral DNA chain. Valacyclovir contains; TheDNA synthesis blocked Destabilizing the strand Prevention of new viral growth
After oral intake of Valtrex, valacyclovir is fast absorbed from the gastrointestinal tract and bioavailability by 54.5% plus or minus 9.1%.
After absorption occurs, the human serum protein binding capacity is 13 to 18%.
Valacyclovir is rapidly absorbed and approximately 99% of drug get changes into an active form like acyclovir & L-valine by sustaining first pass metabolism & hepatic metabolism by enzymatic hydrolysis.
About 89% of radioactivity gets excreted via urine. The medianvalacyclovir half-life period occurs in 2.5 to 3.3 hours.
Valcivir 500mg tablet should be administered with or without food.
COLD SORE (HERPES LABIALIS)
The prescribed dose of Valtrexis 2 grams should be taken for two times a day for one day in 12 hours apart.
GENITAL HERPES (INITIAL EPISODE)
The prescribed dose of Valtrexis 1 grams should be taken as twice daily for 10 days.
The prescribed dose is 500mg should be administered orally as twice daily for 3 days.
In ceaseless suppressive treatment, the recommended measurements is 1 gram taken as once every day in patients with typical capacities. In patients with 9 repeats for every year, the recommended dosage is 500mg ought to be regulated as once day by day.
IN HIV-1 INFECTED PATIENTS
500mg of Valtrexshould be administered orally as two times a day.
REDUCTION OF TRANSMISSION
500mg of Valtrexshould be taken as once daily.
In this condition, the recommended dose of Valcivir 500mg is 1gm should be given as three times a Day for 7 days.
COLD SORES (HERPES LABIALIS)
The patient’s age of greater or equal to 12 years, the recommended dose of Valtrexis 2 grams should be taken as twice daily for 1 day.
20mg/kg of Valtrexshould be administered orally as three times a day for 5 days. The maximum dose per day is not exceeding 1-gram 3times a day.
THE MAJOR ADVERSE EFFECTS OF VALCIVIR ARE
Thrombotic thrombocytopenia purpura/hemolytic uremic syndrome, Acute renal failure, Central nervous effects
THE COMMON SIDE EFFECTS
Low RBC Increased AST Neutropenia Respiratory tract infection Decreased platelet counts Nasopharyngitis Headache Dizziness Nausea Abdominal pain
POST MARKETING EFFECTS
Visual abnormalities Liver enzyme abnormality Hepatitis Renal failure Aplastic anemia Erythema multiforme Alopecia Facial edema High blood pressure Tachycardia Anaphylactic reactions CNS disorders
This condition occurs during the therapy using with Valtrex, this may leads to death with chronic HIV-1 disease & bone marrow transplant. In this fatal condition treatment should be immediately stopped & monitor the manifestation due to this lethal case.
ACUTE RENAL FAILURE
Use Valcivir 500mg in geriatric patients very carefully. Dosage reduction should be recommended for renal impaired patients. Patients who are receiving nephrotoxic drugs should be taken caution while getting Valcivir 500mg tablets. Patients have no sufficient hydration may leads to precipitation of acyclovir in renal tubules.
CENTRAL NERVOUS SYSTEM EFFECTS
In pediatric patients with or without renal impairment should be identified with nervous problems like agitation, hallucination, confusion, seizures during the treatment with Valtrex. In this condition therapy should be stopped.
No drug- drug interactions occurs in the valacyclovir treatment.
PREGNANCY & LACTATION
The pregnancy category of valacyclovir is B It should be used with caution. Caution should be taken while administering Valcivir 500mg to nursing woman.
Valcivir 500mg should be stored at temperature of 15°C to 25°C. Protect away from moisture, heat & light.
Missed dose condition should be avoided by maintain the regular dosing schedule. Do not skip the dose. If missed dose condition, patient should be get discuss from the medical practitioner & follow the instructions. Avoid self-medication.