Herpevir

Gerpevir has immunostimulating activity. Contains the component acyclovir, which is an analogue of the DNA element deoxyguanidine (purine nucleoside). It demonstrates the greatest effectiveness against herpes zoster viruses and common herpes.

In the case of herpes, acyclovir prevents the formation of new rash elements, reduces the risk of epidermal dissemination and visceral complications, increases the rate of crust formation and reduces pain during the active stage of herpes zoster. It also demonstrates activity against CMV and EBV. [ 1 ]

Indications Herpevir

It is used for the following problems:

• infection of the epidermis and mucous membranes associated with the activity of the herpes simplex virus (types 1 and 2) – for example, primary or recurrent genital herpes;
• preventing the development of the above-mentioned diseases in people with weakened immune systems;
• in people with healthy immunity with herpes zoster;
• chickenpox.

Release form

The product is available in 400 mg tablets, 10 pieces inside a blister pack (1 pack inside a box). It is also available in 200 mg tablets - 10 pieces inside a blister pack, 2 packs inside a pack.

Pharmacodynamics

Due to the structural similarity of acyclovir to deoxyguanidine, the former is able to interact with the enzymes of the virus, which causes an interruption of its reproduction. [ 2 ]

Once inside a herpes-infected cell, acyclovir, under the influence of the viral TK, is transformed into acyclovir monophosphate. The body's cellular enzymes first convert it into acyclovir-2-phosphate, and then into the active acyclovir-3-phosphate, which selectively blocks the binding of viral DNA. This component has almost no effect on the processes of cellular DNA replication. [ 3 ]

Pharmacokinetics

When administered orally, the drug is partially absorbed (approximately 20%). Taking it with food has almost no effect on absorption. It is rather weakly synthesized with plasma protein (by 9-33%).

Herpevir penetrates well into tissue fluids, crosses the placenta and BBB, and is excreted in breast milk. Cmax values are noted after 1.5-2 hours.

The half-life after oral administration is approximately 3 hours; in case of renal insufficiency it is extended to 19.5 hours.

Excretion occurs mainly via the kidneys, unchanged; some is excreted in the form of the metabolic component 9-carboxymethoxymethylguanine.

Dosing and administration

Gerpevir should be used orally. Therapy should be started when the first symptoms of the disease develop. During the treatment period, it is necessary to drink large amounts of liquid.

For children aged 3 years and older and adults, for the treatment of primary infections associated with common herpes types 1-2, a daily dosage of 1 g is prescribed, which is used in 5 doses. The therapeutic cycle lasts 5 days.

For lesions caused by herpes zoster, the daily dose is: children aged 3-6 years – 1600 mg; persons over 6 years – 3200 mg. The dosage should be divided into 4 doses. The treatment cycle should last at least 5 days.

For people with immunodeficiency (also after bone marrow or organ transplantation, or in case of intestinal absorption disorders), 0.4 g of the drug is administered 5 times a day; the treatment cycle lasts at least 5 days, and can be extended to 10 days if necessary.

For adults with healthy immunity, to prevent the development of infection associated with the herpes simplex virus types 1-2, the daily dosage is 0.8 g (0.2 g 4 times a day with a 6-hour interval or 0.4 g 2 times a day with a 12-hour interval). Sometimes the daily dose can be reduced to 0.6 g (in 2-3 doses). People with severe immunodeficiency take 0.4 g of the medication 4 times a day. The duration of the preventive treatment cycle is selected individually.

Adults with healthy immunity for lesions caused by herpes zoster are prescribed 4000 mg of the drug per day (0.8 g 5 times per day). The therapy cycle lasts 1 week.

For elderly people or those with disorders of renal secretory activity, the dosage of the drug should be reduced, taking into account the CC indicators:

• for infections associated with Herpes simplex, with a CC level below 10 ml/minute, the daily dose is 0.4 g in 2 doses with at least a 12-hour break;
• for lesions caused by the herpes zoster form, as well as for maintenance treatment of individuals with significantly weakened immunity (CC level is within 10-25 ml/minute), 2400 mg of the substance is used per day in 3 doses, with an 8-hour interval;
• People with a CC level of less than 10 ml/minute need to reduce the daily dosage to 1600 mg in 2 doses, with a 12-hour break.

Application for children

It is prohibited to use the medication in tablet form in persons under 3 years of age.

Use Herpevir during pregnancy

The drug can be prescribed during pregnancy only under strict indications. Breastfeeding should be discontinued during the therapy period.

Contraindications

Main contraindications:

• severe intolerance to valacyclovir, acyclovir or other components of the drug;
• dehydration;
• severe forms of renal dysfunction.

Side effects Herpevir

Side effects include:

• gastrointestinal disorders: vomiting, intestinal colic, diarrhea and nausea;
• manifestations of allergy: itching, fever, epidermal rash and swelling;
• disorders of the nervous system: fatigue, headache and dizziness;
• changes in test results: increased levels of urea, liver transaminases, bilirubin and creatinine;
• Others: deterioration of hematological reactions; anorexia is occasionally observed; alopecia develops occasionally.

Overdose

Manifestations of intoxication: nausea, dyspnea, headache and diarrhea, convulsions, vomiting, renal failure, comatose and lethargic state.

Procedures are performed to support the functioning of vital organs; hemodialysis is performed.

Interactions with other drugs

Concomitant use with probenecid results in a decrease in the excretion rate of the drug.

The combination of Gerpevir and nephrotoxic drugs potentiates their nephrotoxic activity, especially in cases of renal dysfunction.

Storage conditions

Gerpevir should be stored in a place closed to small children, sunlight and moisture. Temperature values are within the range of 8-15°C.

Shelf life

Herpevir can be used for a period of 36 months from the date of production of the medicinal substance.

Analogues

Analogues of the drug are Geviran and Acyclovir.