Famvir, 500 mg 3 pcs

Pharmacodynamics

Famcyclovir is rapidly converted after oral administration into penciclovir which has activity against human herpes viruses including Varicella zoster and Herpes simplex viruses 1 and II as well as Epstein-Barr and cytomegalovirus.

Penciclovir enters virus-infected cells where it is rapidly converted to monophosphate by the action of viral thymidine kinase, which in turn is converted to triphosphate with the help of cellular enzymes. Penciclovir triphosphate stays in virus-infected cells for more than 12 hours, suppressing viral DNA synthesis and viral replication. The half-life of penciclovir triphosphate in cells infected with Varicella zoster, Herpes simplex I and II viruses is 9, 10 and 20 hours, respectively. The concentration of penciclovir triphosphate in uninfected cells does not exceed the minimum detectable, so in therapeutic concentrations penciclovir has no effect on uninfected cells.

Penciclovir is active against recently discovered acyclovir-resistant strains of Herpes simplex virus with an altered DNA polymerase.

The incidence of resistance to famiclovir (penciclovir) does not exceed 0.19-0.3% in patients with compromised immune status. Administration of famcyclovir significantly reduces the severity and duration of post-herpetic neuralgia in patients with herpes zoster.

In patients with impaired immune status due to infection with human immunodeficiency virus (HIV), famcyclovir at a dose of 500 mg twice daily reduces the number of days of Herpes simplex virus excretion (both with and without clinical manifestations).

Pharmacokinetics

Famcyclovir is quickly and almost completely absorbed after oral administration and is rapidly converted to active penciclovir. Bioavailability of penciclovir after oral administration of Famvir is 77%.

The maximum concentration of pencyclovir after oral administration of 125 mg, 250 mg or 500 mg of Famciclovir is reached after an average of 45 minutes and is 0.8 µg/ml, 1.6 µg/ml and 3.3 µg/ml, respectively. The half-life of pencyclovir from plasma in the final phase after receiving single and repeated doses is about 2 hours. No cumulation has been observed with repeated doses of the drug. Binding to plasma proteins of pencyclovir and its 6-deoxy precursor is less than 20%.

Famcyclovir is excreted mainly in the form of penciclovir and its 6-deoxy precursor, which are excreted unchanged in the urine; famcyclovir is not detected in the urine.

Indications

Active ingredient

Composition

1 coated tablet contains:

the active ingredient:

500 mg famcyclovir,

excipients:

hydroxypropylcellulose,

anhydrous lactose,

p> sodium glycolate starch,

Magnesium stearate;

film coating:

Hypromellose, titanium dioxide,

PEG.

How to take, the dosage

Ingestion, regardless of meals, without chewing, with water. Treatment with the drug should be started as soon as possible, immediately after the appearance of the first symptoms of the disease (tingling, itching and burning).

Infection caused by Varicella zoster virus (herpes zoster) in patients with normal immunity. The recommended dose is 500 mg 3 times daily for 7 days. This route of administration reduces the duration of postherpetic neuralgia. In the acute phase of the disease for resolution of skin manifestations the recommended dose is 250 mg 3 times a day or 500 mg 2 times a day or 750 mg once a day for 7 days.

Ophthalmoherpes caused by Varicella zoster virus in patients with normal immunity. The recommended dose is 500 mg 3 times daily for 7 days.

Infection caused by Varicella zoster virus (herpes zoster) in immunocompromised patients. The recommended dose is 500 mg 3 times a day for 10 days.

Infection caused by Herpes simplex virus (labial or genital herpes) in patients with normal immunity. In primary genital herpes, the recommended dose is 250 mg 3 times daily for 5 days. In genital herpes relapses, 1000 mg 2 times daily for 1 day or 125 mg 2 times daily for 5 days, or 500 mg once, followed by 3 doses of 250 mg every 12 hours. For relapses of labial herpes, 1500 mg once daily for 1 day or 750 mg twice daily for 1 day.

Infection caused by Herpes simplex virus (labial or genital herpes) in immunocompromised patients. The recommended dose is 500 mg twice daily for 7 days.

For prevention of exacerbations of recurrent infection caused by Herpes simplex virus – suppressive therapy – 250 mg 2 times a day is prescribed. The duration of therapy depends on the severity of the disease. Periodic evaluation of possible changes in the course of the disease after 12 months is recommended. In HIV-infected patients the effective dose is 500 mg 2 times a day.

Patients aged ≥65 years. In elderly patients with normal renal function, correction of the dosing regimen of famcyclovir is not required.

Patients with impaired renal function. In patients with impaired renal function a decrease in clearance of penciclovir is noted. Correction of the dosing regimen depending on creatinine Cl is presented in the tables.

Table 1

Minimum dosing regimen versus creatinine Cl for infection with Varicella zoster virus (herpes zoster) in patients with normal immunity

Table 1 Dosing regimen for 7 daysCreatinineCl, ml/min Adjusted dosing regimen for 7 days500 mg 3 times daily≥60500 mg 3 times daily40-59500 mg 2 times daily20-39500 mg 1 time daily250 mg 1 time dailyPatients on hemodialysis250 mg after each dialysis session250 mg 3 times daily≥40250 mg 3 times daily20-39500 mg 1 time daily250 mg 1 time dailyPatients, on hemodialysis250 mg after each dialysis session500 mg 2 times daily≥40500 mg 2 times daily20-39500 mg 1 time daily250 mg 1 time dailyPatients on hemodialysis250 mg after each dialysis session750 mg 1 time daily≥40750 mg 2 times daily20-39500 mg 1 time daily250 mg 1 time dailyPatients on hemodialysis250 mg after each dialysis session

Table 2

Patients with reduced immunity in infection with Varicella zoster virus (herpes zoster shingles)

Dosing regimen adjustment depending on creatinine Cl Dosing regimen for 10 daysCreatinine Cal, ml/min Adjusted dosing regimen for 10 days500 mg 3 times daily≥60500 mg 3 times daily40-59500 mg 2 times daily20-39500 mg 1 time daily250 mg 1 time dailyPatients on hemodialysis250 mg after each dialysis session/p>

Table 3

Patients with normal immunity in Herpes simplex virus infection

CreatinineCl dosing regimen correction in patients with normal immunity

Dosing regimenCreatinine Cl, ml/minCorrected dosing regimenFirst episode250 mg 3 times daily for 5 days≥40250 mg 3 times daily for 5 days20-39250 mg 2 times daily for 5 days250 mg 1 time daily for 5 daysPatients, on hemodialysis250 mg after each dialysis session, for 5 daysFor genital herpes recurrences1000 mg 2 times a day for 1 day≥601000 mg 2 times a day for 1 day40-59500 mg 2 times a day for 1 day20-39500 mg once250 mg once oncePatients, on hemodialysis250 mg once daily after a dialysis session125 mg twice daily for 5 days ≥20125 mg twice daily for 5 days125 mg oncePatients on hemodialysis125 mg once after each dialysis session for 5 days500 mg once followed by 3 doses of 250 mg every 12 h≥40500 mg once followed by 3 doses of 250 mg every 12 h20-39250 mg once followed by 3 doses of 250 mg every 12 h250 mg once followed by 250 mg after 24 hoursPatients On hemodialysis250 mg once after a dialysis sessionPatients with recurrence of labial herpes1500 mg once≥601500 mg once40-59750 mg once20-39500 mg once250 mg oncePatients, on hemodialysis250 mg once daily after a dialysis session750 mg twice daily ≥60750 mg twice daily for 1 day40-59750 mg once daily20-39500 mg once daily250 mg once dailyPatients on hemodialysis250 mg once daily after a dialysis session

Table 4

Correction of dosing regimen depending on creatinine Cl in prevention of relapses of Herpes simplex virus-induced infection (suppressive therapy)

Dosing regimenCreatinineCl, mL/minCorrected dosing regimen250 mg 2 times daily≥40250 mg 2 times daily20-39125 mg 2 times daily125 mg once dailyPatients on hemodialysis125 mg after each dialysis session

Table 5

Dosing regimen adjustment depending on creatinine Cl for Herpes simplex virus infection (labial or genital herpes) in immunocompromised patients

Dosing regimen for 7 daysCreatinineCl, ml/min Adjusted dosing regimen for 7 days500 mg 2 times daily≥40500 mg 2 times daily20-39500 mg once daily250 mg once dailyPatients on hemodialysis250 mg after each dialysis session

Patients with renal failure who are on hemodialysis. Since penciclovir plasma concentrations decrease by 75% after a 4-hour hemodialysis procedure, famiclovir should be taken immediately after the hemodialysis procedure. The recommended dose is 250 mg (for patients with herpes zoster) and 125 mg (for patients with genital herpes).

Patients with impaired liver function. For patients with liver dysfunction of mild to moderate severity, no dose adjustment of the drug is required.

Patients of Negro race. The efficacy of a 1-day dosage of 1,000 mg twice daily of Famvir for the treatment of genital herpes relapse in immunocompetent black patients was not greater than that of placebo. The clinical significance of drug dosing regimens for the treatment of both genital herpes relapses (within 2 or 5 days) and other infectious lesions caused by Varicella zoster and Herpes simplex viruses is unknown.

Interaction

No clinically significant pharmacokinetic interactions of famcyclovir with other drugs were observed.

No effect of famcyclovir on the cytochrome P450 system was found.

Drugs that block tubular secretion may increase the concentration of penciclovir in plasma.

Special Instructions

Treatment should begin as soon as the diagnosis is made.

Genital herpes is a sexually transmitted disease. During relapses, the risk of infection increases. If there are clinical signs of the disease, patients should avoid sexual contact even if antiviral treatment is begun.

The effect on the ability to drive and operate machinery

The effect of Famvir on the ability to drive and operate machinery has not been studied.

Contraindications

Hypersensitivity to famcyclovir or any of the components of the drug Famvir. Hypersensitivity to penciclovir.

Side effects

Mild to moderate headaches and nausea were reported with the same frequency as in patients receiving placebo.

Vomiting, dizziness, diarrhea, skin rash and, mainly in older patients, confusion and hallucinations were rarely reported.

In immunocompromised patients abdominal pain, fever and rarely granulocytopenia and thrombocytopenia were also reported.

Overdose

Described cases of overdose (10.5 g) of Famvir were not accompanied by clinical manifestations.

Treatment: symptomatic. In case of non-compliance with the recommendations to reduce the dose of famcyclovir with regard to renal function in patients with renal disease there have been cases of acute renal failure.

Penciclovir is excreted by hemodialysis

Pregnancy use

Experimental studies have shown no embryotoxic and teratogenic effects of famciclovir and penciclovir. Since the safety of Famvir in pregnant and breastfeeding women has not been studied, its use during pregnancy and lactation is not recommended unless the possible benefit of treatment for the mother exceeds the potential risk to the fetus and child.

Studies in rats treated with oral famiclovir have shown that pencyclovir is excreted with breast milk. It is not known whether pencyclovir is excreted with breast milk in humans.

Famcyclovir has no significant effect on the sperm count, morphology, or motility of human sperm. A decrease in fertility was noted in an experimental model in male rats treated with famcyclovir at a dose of 500 mg/kg body weight, no pronounced decrease in fertility was noted in female rats.

Periatric use:

The efficacy and safety of Famvir in children have not been studied, so its use in this category of patients is not recommended unless the potential benefit of therapy exceeds the possible risk of complications.

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