Virfoten (Tablets) Instructions for Use

Marketing Authorization Holder

Pharmasintez, JSC (Russia)

Manufactured By

Pharmasintez, JSC (Russia)

Or

Pharmasintez-Tyumen, LLC (Russia)

ATC Code

J05AF07 (Tenofovir disoproxil)

Active Substance

Tenofovir (Rec.INN registered by WHO)

Dosage Forms

	Virfoten	Film-coated tablets, 150 mg: 30, 60, 100, 500 or 1000 pcs.
		Film-coated tablets, 300 mg: 30, 60, 100, 500 or 1000 pcs.

Dosage Form, Packaging, and Composition

Film-coated tablets from light brown with an orange tint to brown, round, biconvex; on the cross-section, the core is white or white with a yellowish tint.

Excipients: sodium carboxymethyl starch (primogel) – 16.5 mg, sodium stearyl fumarate – 5.9 mg, croscarmellose sodium – 21 mg, lactose monohydrate – 36 mg, hypromellose E-15 – 4.8 mg, microcrystalline cellulose (type 101) – 65.8 mg.

Film coating composition hypromellose – 74.2%, macrogol 6000 (polyethylene glycol 6000) – 14.3%, titanium dioxide – 3.5%, talc – 2.3%, iron oxide red dye – 1.4%, iron oxide yellow dye – 4.3%.

10 pcs. – blister packs (3) – cardboard packs.
10 pcs. – blister packs (6) – cardboard packs.
10 pcs. – blister packs (10) – cardboard packs.
30 pcs. – polymer jars (1) – cardboard packs.
60 pcs. – polymer jars (1) – cardboard packs.
100 pcs. – polymer jars (1) – cardboard packs.
500 pcs. – polymer jars (1) – cardboard packs.
1000 pcs. – polymer jars (1) – cardboard packs.

Film-coated tablets from light brown with an orange tint to brown, oval, with pointed ends, biconvex; on the cross-section, the tablet core is white or white with a yellowish tint.

Excipients: sodium carboxymethyl starch (primogel) – 33 mg, sodium stearyl fumarate – 11.8 mg, croscarmellose sodium – 42 mg, lactose monohydrate – 72 mg, hypromellose E-15 – 9.6 mg, microcrystalline cellulose (type 101) – 131.6 mg.

Film coating composition hypromellose – 74.2%, macrogol 6000 – 14.3%, titanium dioxide – 3.5%, talc – 2.3%, iron oxide red dye – 1.4%, iron oxide yellow dye – 4.3%.

10 pcs. – blister packs (3) – cardboard packs.
10 pcs. – blister packs (6) – cardboard packs.
10 pcs. – blister packs (10) – cardboard packs.
30 pcs. – jars (1) – cardboard packs.
60 pcs. – jars (1) – cardboard packs.
100 pcs. – jars (1) – cardboard packs.
500 pcs. – jars (1) – cardboard packs.
1000 pcs. – jars (1) – cardboard packs.

Clinical-Pharmacological Group

Antiviral drug active against HIV

Pharmacotherapeutic Group

Antiviral [HIV] agent

Pharmacological Action

Antiviral agent, a nucleotide reverse transcriptase inhibitor. Tenofovir is converted in vivo into tenofovir, an analogue of nucleoside monophosphate (nucleotide) adenosine monophosphate.

Tenofovir is subsequently converted into an active metabolite, tenofovir diphosphate, which inhibits the activity of HIV-1 reverse transcriptase by incorporating into the viral DNA molecule and disrupting DNA chain synthesis.

Tenofovir is a weak inhibitor of mammalian DNA polymerases α, β, and mitochondrial DNA polymerase γ.

Pharmacokinetics

When taken on an empty stomach, the bioavailability of tenofovir is approximately 25% and up to 40% (with food); it improves when taken with food, especially high-fat food.

Food intake does not have a clinically significant effect on the efficacy of tenofovir. After a single oral dose of 300 mg, C_max in blood serum is reached in 1±0.4 hours.

The pharmacokinetics of tenofovir is dose-dependent. T_1/2 from the cell > 60 hours.

After a single oral dose, the T_1/2 of tenofovir is approximately 17 hours.

After multiple oral doses of 300 mg once/day (under non-fasting conditions), 32±10% of the administered dose is determined in the urine over more than 24 hours.

Tenofovir is excreted by the kidneys, through glomerular filtration and active tubular secretion.

Indications

Treatment of HIV-1 infection as part of combined antiretroviral therapy in adults.

ICD codes

Dosage Regimen

Administer orally, with or without food. The recommended dose for adults is 300 mg once daily.

Swallow the tablet whole; do not crush or chew.

For patients with renal impairment, adjust the dosing interval based on creatinine clearance (CrCl). For CrCl 30-49 mL/min, administer 300 mg every 48 hours.

For CrCl 10-29 mL/min, administer 300 mg every 72 to 96 hours.

For patients on hemodialysis, administer a 300 mg dose every 7 days, administered after the dialysis session is completed.

Determine creatinine clearance prior to initiating therapy. Monitor renal function and serum phosphorus regularly during treatment, especially in patients with risk factors for renal impairment.

Avoid concomitant use with other nephrotoxic drugs. Use only as part of a combined antiretroviral therapy regimen.

Adverse Reactions

Metabolism: very common – hypophosphatemia; rare – lactic acidosis; possible – hypokalemia.

Digestive system: very common – diarrhea, vomiting, nausea; common – flatulence; rare – pancreatitis, increased transaminase activity; very rare – hepatitis; possible – hepatic steatosis.

Musculoskeletal system: possible – rhabdomyolysis, osteomalacia, muscle weakness, myopathy.

Urinary system: rare – acute renal failure, proximal renal tubulopathy (including Fanconi syndrome), hypercreatininemia; very rare – acute tubular necrosis; frequency unknown – nephritis (including acute interstitial), nephrogenic diabetes insipidus.

Other: very common – dizziness; rare – rash; very rare – dyspnea, asthenia.

Contraindications

Hypersensitivity to tenofovir.

Use in Pregnancy and Lactation

If use during pregnancy is necessary, the expected benefit of therapy for the mother and the potential risk to the fetus should be weighed.

Due to identified changes in bone tissue against the background of tenofovir use, and limited experience of use, it is recommended to use Tenofovir with caution during pregnancy.

Women of childbearing age should use reliable methods of contraception during treatment.

If use during lactation is necessary, breastfeeding should be discontinued.

Use in Renal Impairment

Tenofovir should be used with caution in renal failure with CrCl less than 50 ml/min, including patients on hemodialysis.

With CrCl less than 30 ml/min, the use of Tenofovir is not recommended; if use is necessary, renal function should be carefully monitored and the interval between drug administration should be adjusted.

Newly occurring or progressive renal failure can lead to acute renal failure and Fanconi syndrome.

Determination of CrCl is necessary before starting treatment with tenofovir.

Monitoring of creatinine clearance and serum phosphorus is necessary in patients at increased risk of developing or progressing renal failure.

The use of tenofovir simultaneously with or after recent treatment with nephrotoxic drugs should be avoided.

Special Precautions

Tenofovir should be used with caution in renal failure with CrCl less than 50 ml/min, including patients on hemodialysis.

With CrCl less than 30 ml/min, the use of Tenofovir is not recommended; if use is necessary, renal function should be carefully monitored and the interval between drug administration should be adjusted.

Newly occurring or progressive renal failure can lead to acute renal failure and Fanconi syndrome.

Determination of CrCl is necessary before starting treatment with tenofovir.

Monitoring of creatinine clearance and serum phosphorus is necessary in patients at increased risk of developing or progressing renal failure.

The use of tenofovir simultaneously with or after recent treatment with nephrotoxic drugs should be avoided.

The use of tenofovir simultaneously with combined antiviral drugs containing Tenofovir and adefovir dipivoxil should be excluded.

Tenofovir should be used only as part of an appropriate antiretroviral combination therapy in HIV-1 infected patients.

When using tenofovir, the development of Fanconi syndrome, accompanied by hypophosphatemia, hypoglycemia, proteinuria, normoglycemic glucosuria, is possible; in some cases, acute renal failure may develop.

In the early stages, the course may be asymptomatic, or accompanied by myalgia; in most cases, the symptoms disappear after discontinuation of tenofovir.

Risk factors include low body weight, the presence of kidney disease at the start of therapy.

The frequency of nephrotoxic side effects is extremely low in patients with initially normal renal function.

Drug Interactions

With simultaneous use of tenofovir with didanosine, the plasma concentration of didanosine increases (this combination is not recommended; if combination therapy is necessary, the dose of didanosine should be reduced).

With concomitant use, a decrease in the plasma concentration of atazanavir and an increase in the concentration of tenofovir occur.

Tenofovir should be used with atazanavir only with additional boosting of the latter with ritonavir.

With concomitant use of the lopinavir/ritonavir combination with tenofovir, the plasma concentration of tenofovir increases.

Darunavir increases the concentration of tenofovir by 20-25%.

With this combination, darunavir and Tenofovir should be used in standard doses, while the nephrotoxic effect of tenofovir should be carefully monitored.

Tenofovir is mainly excreted from the body by the kidneys.

With the concomitant use of tenofovir with drugs that reduce renal function or suppress/stop active tubular secretion, an increase in the serum concentration of tenofovir and/or an increase in the concentrations of other drugs excreted by the kidneys is possible.

Ganciclovir, valganciclovir and cidofovir compete with tenofovir for active tubular secretion by the kidneys, resulting in an increase in the plasma concentration of tenofovir (clinical observation is necessary to monitor possible side effects).

Nephrotoxic drugs can increase the plasma concentration of tenofovir.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.