Acyclovir 400 mg.
Pharmacological action:
An antiviral drug, especially effective against herpes simplex viruses (a virus that causes damage to the skin and mucous membranes) and herpes zoster (a virus that causes a disease of the central and peripheral nervous system with the appearance of a blistering rash along the sensory nerves).
Acyclovir is an analogue of the purine nucleoside deoxyguanidine, a normal component of DNA (deoxyribonucleic acid - a component of the cell nucleus responsible for the transfer of hereditary information).
The similarity of the structures of acyclovir and deoxyguanidine allows acyclovir to interact with viral enzymes, which leads to the interruption of viral replication.After the introduction of acyclovir into a cell affected by herpes, under the influence of thymidine kinase secreted by the virus, aiclovir is converted into acyclovir monophosphate, which is converted into acyclovir diphosphate by host cell enzymes. and then into the active form of acyclovir triphosphate, which blocks the replication of viral DNA (a complex intracellular mechanism of DNA division, which results in the multiplication of viruses).The drug acts selectively on viral DNA synthesis. Acyclovir triphosphate has virtually no effect on the DNA replication of the host cell (human cell).
When taken orally, acyclovir is only partially absorbed (about 20%). The half-life (the time during which one-third of a dose of the drug is eliminated) when taken orally and administered into a vein is about 3 hours. It is excreted mainly by the kidneys in unchanged form, partly in the form of a metabolite (metabolite product).In case of renal failure, the half-life increases significantly (up to 19.5 hours).
Indications for use:
Acyclovir for herpes prevents the formation of new rash elements, reduces the likelihood of skin dissemination (spread through the skin) and visceral complications (complications to internal organs), accelerates the formation of crusts, and reduces pain in the acute phase of herpes zoster.
Acyclovir is administered intravenously for infections caused by the herpes simplex virus in patients with impaired immune systems; in severe forms of primary genital infections if the infections are caused by the herpes simplex virus; for infections caused by the herpes zoster virus; for the prevention of infections caused by the herpes simplex virus in patients with severely impaired immune systems (during organ transplantation, tumor chemotherapy).
The drug also has an immunostimulating effect (aimed at activating the body's defenses).
Directions for use:
Acyclovir is used orally, intravenously and locally (in the form of ointment and cream).
Acyclovir tablets are prescribed for infections of the skin and mucous membranes caused by the herpes simplex virus, and for the prevention of these diseases in patients with impaired immune systems, and in patients with herpes zoster - with a normal immune system. For infections caused by the herpes simplex virus, adults are given 0.5 tablets (0.2 g) 5 times a day (except at night), and for prevention - 0.5 tablets 4 times a day; for herpes zoster - 2 tablets (0.8 g) 5 times a day. Children over 2 years of age are prescribed the adult dose; up to 2 years - half the adult dose. The duration of treatment is usually 5 days, for herpes zoster - another 3 days after the signs of the disease disappear. It is not recommended to administer the drug to newborns.
Administered intravenously to adults and children over 12 years of age, 5 mg/kg 3 times a day (every 8 hours); for herpeszoster (shingles) in patients with immune system disorders - 10 mg/kg every 8 hours; children from 3 months. up to 12 years - 5 mg/kg (250 mg/m2 body surface).