Epivir 150 mg Tablets

Brand name

The trade name of the drug is Epivir. This is the registered name under which the drug is known in medical practice and is available in the pharmacy network.

International Nonproprietary Name (INN)

The international nonproprietary name is lamivudine. It denotes the active active ingredient and is used in pharmacology at the international level.

Form of release

Epivir is available in two main forms: film-coated tablets with dosages of 150 mg and 300 mg, packed in blisters of 10 pieces or vials of 60 pieces, and solution for oral administration with a concentration of 10 mg/mL in 240 ml vials with a measuring syringe. The tablets have white or slightly creamy color, oval shape, and the solution has a clear consistency with a fruity aroma, which facilitates its use in children.

Composition

Active ingredient

The main active ingredient is lamivudine. One tablet contains 150 mg or 300 mg of lamivudine, and 1 ml of the solution contains 10 mg.

Auxiliary ingredients

The tablets include substances such as microcrystalline cellulose, sodium starch glycolate, magnesium stearate, and a coating of hypromellose, titanium dioxide, polyethylene glycol, and polysorbate 80. The solution contains sucrose, propylene glycol, methylparaben, propylparaben (preservatives), citric acid, sodium citrate, and strawberry flavoring.

Pharmacologic Properties

Pharmacodynamics

Lamivudine, the active ingredient in Epivir, is a nucleoside analog that inhibits HIV reverse transcriptase and hepatitis B virus DNA polymerase. Upon entry into infected cells, lamivudine is phosphorylated to the active form, lamivudine triphosphate, which is competitively incorporated into the growing viral DNA strand. This leads to premature termination of DNA synthesis, blocking viral replication. In HIV infection, the drug inhibits reverse transcription of viral RNA into DNA, and in hepatitis B, it prevents the assembly of viral particles, reducing their production in hepatocytes.

Epivir demonstrates high activity against HIV-1 and HBV, but does not destroy the viruses completely, but only controls their reproduction. The effect is noticeable after 2-4 weeks in HIV (reduction of viral load) and after 4-8 weeks in hepatitis B (reduction of HBV-DNA level). The drug does not have a direct immunostimulatory effect, but improvement of virologic status contributes to the recovery of CD4-cells in patients with HIV. Lamivudine is characterized by low toxicity to human cells due to its selectivity to viral enzymes.

Pharmacokinetics

Absorption

Lamivudine is rapidly absorbed from the gastrointestinal tract after oral administration. Maximum plasma concentration is reached in 0.5-2 hours, and bioavailability is about 86% for tablets and 68% for the solution. Food intake slows down the rate of absorption, but does not affect the total absorption, which allows taking the drug independently of meals.

Distribution

Lamivudine binds weakly to plasma proteins (less than 36%), mainly to albumin. The volume of distribution is about 1.3 L/kg, indicating penetration into various tissues, including the central nervous system, cerebrospinal fluid and liver tissue. The drug passes the placental barrier and is excreted in breast milk.

Metabolism

Lamivudine undergoes minimal metabolism (5-10%) in the liver. The bulk of the substance is excreted unchanged through the kidneys, which distinguishes it from other nucleoside analogs. A small amount is metabolized to the sulfoxide form, which has no pharmacological activity.

Excretion

The elimination half-life of lamivudine is 5-7 hours in adults and 2-4 hours in children. The drug is excreted mainly through the kidneys (about 70% in unchanged form) by tubular filtration and tubule secretion, the rest of the drug is excreted through the intestine. Complete excretion takes about 24-48 hours.

Indications for Use

Epivir is indicated for the treatment of the following conditions:

• HIV-1 infection in adults and children as part of combination antiretroviral therapy;
• Chronic hepatitis B with active viral replication (HBV-DNA-positive);
• Prevention of HIV infection progression to AIDS;
• Reduction of viral load and maintenance of immune status in HIV;
• Treatment of HIV and HBV co-infection.

The drug is used for both active treatment and long-term control of infections.

Contraindications

The use of Epivir is prohibited in:

• Hypersensitivity to lamivudine or auxiliary components;
• Severe renal insufficiency (creatinine clearance less than 30 ml/min) without dose adjustment;
• Children under 3 months of age (for solution) or body weight less than 14 kg (for tablets);
• Severe history of severe anemia or neutropenia;
• Pregnancy (first trimester) and lactation without strict indications.

With caution prescribe in pancreatitis, obesity, chronic hepatic insufficiency.

Method of Administration and Dosage

How to take

Epivir tablets are taken orally, drinking water (100-150 ml), regardless of meals. The solution is measured with a syringe and taken orally, also without reference to food. Tablets are not chewed or crushed to preserve the stability of the active ingredient.

Dosages for adults and children

Adults and children with a body weight greater than 25 kg

For HIV: 150 mg twice daily or 300 mg once daily. For hepatitis B: 100 mg once daily.

Children 3 months to 25 kg

Dosage is 4 mg/kg body weight twice daily (maximum 150 mg twice daily) or 8 mg/kg once daily (maximum 300 mg) for solution.

Dose adjustment for certain conditions

In renal insufficiency: creatinine clearance 30-50 ml/min - 150 mg once daily; 15-29 ml/min - 100 mg first day, then 50 mg/day. In hepatic insufficiency correction is not required.

Side Effects

Possible adverse reactions include:

• General: fatigue, headache, fever;
• GI: nausea, diarrhea, abdominal pain;
• Nervous system: insomnia, dizziness;
• Metabolism: lactoacidosis, increased transaminase levels;
• Allergic reactions: rash, itching, urticaria;
• Other: myalgia, peripheral neuropathy.

The side effects are more often manifested at the beginning of therapy and require observation.

Overdose

Symptoms of overdose

Doses above 600-1000 mg may cause nausea, dizziness, lactoacidosis, weakness, convulsions.

First aid measures

Stop taking, call a doctor. Gastric lavage (if less than one hour has passed), give activated charcoal. Symptomatic treatment is required.

Drug Interactions

Influence on the effect of other drugs

Epivir increases the toxicity of zidovudine when co-administered. Trimethoprim increases the concentration of lamivudine in the blood. Ribavirin may decrease its efficacy.

Compatibility with alcohol and food

Alcohol increases the risk of lactoacidosis. Food does not affect absorption, improving tolerability.

Special Precautions

Use in pregnancy and breastfeeding

Use in the first trimester is limited; in the second and third trimester, by strict indications. Breast-feeding is prohibited due to penetration into milk.

Effect on driving and mechanisms

The drug may cause dizziness, which requires caution when driving.

Particularities of use in elderly people and children

In the elderly, the dose is adjusted in case of impaired renal function. In children, it is used with regard to body weight and form of release.