Acyclovir
Buy Acyclovir at
DOSAGE FORMS
tablets 0.4g
tablets 400mg
MANUFACTURERS
Obolenskoye FP (Russia)
GROUP
Antiherpetic drugs
COMPOUND
Active substance: Acyclovir.
INTERNATIONAL NON-PROPENTED NAME
Acyclovir
SYNONYMS
Acigerpin, Acic-Ophthal, Acyclovir Belupo, Acyclovir Hexal, Acyclovir Sandoz, Acyclovir forte, Acyclovir-Akos, Acyclovir-Acri, Acyclostad, Vero-Acyclovir, Vivorax, Virolex, Gervirax, Herpevir, Herperax, Herpesin, Zovirax, Lovir, Medovir, Tsevirin, Cycloviral Sediko
PHARMACHOLOGIC EFFECT
Antiviral. It has a highly selective effect on herpes simplex viruses type 1 and 2, herpes zoster, Epstein-Barr and cytomegalovirus. Easily passes through the corneal epithelium ( eye ointment) and creates a therapeutic concentration in the ocular fluid. When used topically in the form of a cream, it is not absorbed into the systemic circulation. Penetrates through the BBB and placental barrier, excreted in breast milk. For herpes, it prevents the formation of new rash elements, reduces the likelihood of skin dissemination and visceral complications, accelerates the formation of crusts, reduces pain in acute phase herpes zoster. Has an immunostimulating effect.
INDICATIONS FOR USE
Primary and recurrent herpetic lesions of the skin and mucous membranes (including genital herpes), herpetic lesions in patients with immunodeficiency (treatment and prevention), herpes zoster, chicken pox, simple herpetic keratitis.
CONTRAINDICATIONS
Hypersensitivity, breastfeeding.
SIDE EFFECT
Headache, fatigue, neurological disorders, shortness of breath, nausea, vomiting, diarrhea, intestinal colic, fever, edema, lymphadenopathy, increased levels of bilirubin, urea, creatinine, transient increase in the activity of liver transaminases, allergic reactions in the form of skin rash, itching. With intravenous administration - agitation, impaired consciousness, lethargy, tremor, convulsions, hallucinations, psychosis, coma; reactions at the IV injection site - local inflammation, phlebitis. When used externally - erythema, peeling, burning sensation, burn.
INTERACTION
Probenecid slows down excretion (blocks tubular secretion).
METHOD OF APPLICATION AND DOSAGE
Orally, adults and children over 2 years old - 0.2 g 5 times a day (except at night), for prevention - 0.2 g 4 times a day; for herpes zoster - 0.8 g 4 times a day; children under 2 years old - half the dose for adults. The course of treatment is usually 5 days, for herpes zoster - another 3 days after the signs of the disease disappear. Preventative treatment For organ transplants, it takes 6 weeks.
OVERDOSE
Symptoms: headache, neurological disorders, shortness of breath, nausea, vomiting, diarrhea, renal failure, lethargy, convulsions, coma. Treatment: life support important functions, hemodialysis.
SPECIAL INSTRUCTIONS
Restrictions on use: Pregnancy. To prevent crystallization in the tubular apparatus, it is recommended to take large quantity liquids. Caution should be exercised in patients with psychoneurotic disorders, impaired renal and liver function, electrolyte disturbances, and severe hypoxia. It is recommended to apply the cream using rubber gloves to prevent infection of other areas of the skin. For more detailed information, see the instructions for use.
STORAGE CONDITIONS
In a dry place, at a temperature not exceeding 25 °C.
Compound
1 tablet contains:
active substance: acyclovir 400 mg;
Excipients: potato starch, lactose (milk sugar), povidone, sugar (sucrose), sodium lauryl sulfate, magnesium stearate.
Indications for use Acyclovir Forte
Treatment and prevention of infections caused by Herpes simplex viruses types 1 and 2 and Varicella zoster:
- herpes simplex of the skin and mucous membranes (primary and recurrent);
- genital herpes (primary and recurrent);
- herpes zoster (shingles);
- chickenpox (in the first 24 hours after the appearance of a typical rash);
- in patients with severe immunodeficiency (including after transplantation, when taking immunosuppressive drugs, in HIV-infected patients, during chemotherapy).
Contraindications to the use of Acyclovir Forte
- hypersensitivity to acyclovir, ganciclovir or components of the drug;
- lactation period (breastfeeding).
- childhood up to 3 years.
WITH caution the drug should be prescribed for dehydration, renal failure, neurological disorders, incl. in the anamnesis.
The dosage regimen is set individually depending on the severity of the disease.
In the treatment of infections of the skin and mucous membranes caused by the Herpes simplex virus type 1 and 2,
Acyclovir is prescribed 200 mg 5 times a day for 5 days at intervals of 4 hours during the day and at intervals of 8 hours at night. In more severe cases of the disease, it is possible to increase the course of treatment.
Included complex therapy with severe immunodeficiency, including advanced clinical picture HIV infections (including early clinical manifestations HIV infection and AIDS stage), after bone marrow implantation Prescribe 400 mg 5 times a day.
To prevent relapses of infections caused by Herpes simplex virus types 1 and 2, in patients with normal immune status and in case of relapse of the disease Prescribe 200 mg 4 times a day every 6 hours.
To prevent infections caused by Herpes simplex virus types 1 and 2,adults and children over 2 years old
with immunodeficiency, the drug is prescribed 200 mg 4 times a day every 6 hours, maximum dose- 400 mg 5 times a day.
, adults
Prescribe 800 mg 5 times a day at intervals of 4 hours during the day and at intervals of 8 hours at night. The duration of treatment is 7-10 days. Children over 2 years old
prescribed 20 mg/kg body weight 4 times a day for 5 days, children weighing more than 40 kg
the drug is prescribed in the same dosage as for adults.
In the treatment of herpes zoster (Herpes zoster), adults
Prescribe 800 mg 4 times/day every 6 hours for 5 days. Children over 6 years old
- 800 mg 4 times a day; 2-6 years
- 400 mg 4 times a day; under 2 years old
- 200 mg 4 times a day. More accurately, the dose can be determined at the rate of 20 mg/kg, but not more than 800 mg 4 times a day. The course of treatment is 5 days.
In patients with severe renal impairment (CK) with treatment and prevention of infections caused by the Herpes simplex virus, the drug is prescribed 200 mg 2 times a day at intervals of 12 hours.
For the treatment of infections caused by the Varicella zoster virus, For patients with CC, the drug is prescribed 800 mg 2 times a day at intervals of 12 hours; at CC from 10 to 25 ml/min- 800 mg 3 times a day at intervals of 8 hours.
The drug should be taken during or immediately after meals and washed down with enough water.
pharmachologic effect
Acyclovir is an antiviral (antiherpetic) agent for external use - a synthetic analogue of thymidine nucleoside, which is a natural component of DNA.
In infected cells containing viral thymidine kinase, phosphorylation occurs and is converted to acyclovir monophosphate. Under the influence of acyclovir guanylate cyclase, monophosphate is converted into diphosphate and, under the action of several cellular enzymes, into triphosphate. High selectivity of action and low toxicity to humans are due to the absence of the necessary enzyme for the formation of acyclovir triphosphate in intact cells of the macroorganism.
Acyclovir triphosphate inhibits the synthesis (replication) of viral DNA by three mechanisms: 1) competitively replaces deoxyguanosine triphosphate in DNA synthesis; 2) “integrates” into the DNA chain being synthesized and stops its elongation; 3) inhibits the DNA polymerase enzyme of viruses. As a result, the reproduction of the virus in the human body is disrupted.
The specificity and very high selectivity of action are also due to its predominant accumulation in cells affected by the herpes virus.
Highly active against Herpes simplex viruses type 1 and 2; the virus that causes chickenpox and herpes zoster (Varicella zoster); Epstein-Barr virus (types of viruses are listed in increasing order of the minimum inhibitory concentration of acyclovir).
Moderately active against cytomegalovirus.
In case of herpes, it prevents the formation of new rash elements, reduces the likelihood of skin dissemination and visceral complications, accelerates the formation of crusts, and reduces pain in the acute phase of herpes zoster. Has an immunostimulating effect.
Side effects of Acyclovir Forte
From the digestive system: in isolated cases - abdominal pain, nausea, vomiting, diarrhea; rarely - transient increase in liver enzyme activity, hyperbilirubinemia.
From the hematopoietic system: rarely - leukopenia, erythropenia.
From the side of the central nervous system: rarely - headache, weakness; V in some cases- tremor, dizziness, increased fatigue, drowsiness, hallucinations.
Allergic reactions: skin rash; rarely - allergic dermatitis(when using ointment).
Others: rarely - alopecia, fever, increased levels of urea and creatinine.
special instructions
Acyclovir should be prescribed with caution to patients with impaired renal function and elderly patients due to an increase in the half-life of acyclovir.
When using the drug, it is necessary to ensure the supply of a sufficient amount of fluid.
The ointment is not recommended to be applied to the mucous membranes of the mouth, eyes, and genitals, because the development of severe local inflammation is possible.
The earlier it is started, the higher the effectiveness of treatment when using the ointment.
In patients with immunodeficiency with repeated repeat courses treatment, sometimes the formation of viral resistance to acyclovir occurs.
When taking the drug, kidney function should be monitored (blood urea and plasma creatinine levels).
Drug interactions
When used simultaneously with probenecid, the average half-life of acyclovir increases and the clearance of acyclovir decreases.
When taken simultaneously with nephrotoxic drugs, the risk of developing renal dysfunction increases.
Storage conditions
Store in a dry place, protected from light, out of reach of children, at a temperature not exceeding 25°C.
Release form: Solid dosage forms. Pills.
General characteristics. Compound:
Active ingredient: 400 mg of acyclovir.
Excipients: potato starch, lactose (milk sugar), povidone, sugar (sucrose), sodium lauryl sulfate, magnesium stearate.
An antiviral drug with a highly selective effect on herpes viruses.
Pharmacological properties:
Pharmacodynamics. An antiviral drug, a synthetic analogue of an acyclic purine nucleoside, which has a highly selective effect on herpes viruses. Inside virus-infected cells, under the influence of viral thymidine kinase, a series of sequential reactions of transformation of acyclovir into mono-, di- and triphosphate of acyclovir takes place. Acyclovir a triphosphate is integrated into the viral DNA chain and blocks its synthesis through competitive inhibition of viral DNA polymerase.
In vitro, acyclovir is effective against the herpes simplex virus - Herpes simplex types I and II, against the Varicella zoster virus; higher concentrations are required to inhibit Epstein-Barr virus.
Pharmacokinetics. When taken orally, bioavailability is 15-30%. Acyclovir penetrates well into all organs and tissues of the body, including the brain and skin. Plasma protein binding is 9-33% and is independent of its plasma concentration. The concentration in the cerebrospinal fluid is about 50% of its concentration in plasma. Acyclovir crosses the placental barrier and accumulates in breast milk. The maximum concentration after oral administration of 200 mg 5 times a day is 0.7 mcg/ml, the time to reach the maximum concentration is 1.5-2 hours.
Metabolized in the liver to form the pharmacologically inactive compound 9-carboxymethoxymethylguanine. The half-life in adults with normal renal function is 2-3 hours. In patients with severe renal failure the half-life is 20 hours, with hemodialysis - 5.7 hours (in this case, the concentration of acyclovir in plasma decreases to 60% of the initial value). About 84% is excreted by the kidneys unchanged and 14% in the form of a metabolite. The renal clearance of acyclovir is 75-80% of the total plasma clearance. Less than 2% of acyclovir is excreted from the body through the intestines.
Indications for use:
· Treatment of infections of the skin and mucous membranes caused by Herpes simplex viruses type I and II, both primary and secondary, including.
· Prevention of exacerbations of recurrent infections caused by Herpes simplex viruses type I and II in patients with normal immune status.
· Prevention of primary and recurrent infections caused by Herpes simplex viruses type I and II in patients with immunodeficiency.
· As part of complex therapy for patients with severe immunodeficiency: at the stage of early clinical manifestations and a detailed clinical picture) and in patients who have undergone bone marrow transplantation.
· Treatment of primary and recurrent infections caused by the Varicella zoster virus (chickenpox, as well as herpes zoster).
Important! Get to know the treatment
Directions for use and dosage:
Inside. The drug is taken during or immediately after a meal and washed down with a sufficient amount of water.
The dosage regimen is set individually depending on the severity of the disease.
When treating infections of the skin and mucous membranes caused by Herpes simplex types I and II:
Adults: the drug is prescribed 200 mg 5 times a day for 5 days at 4-hour intervals during the day and at 8-hour intervals at night. In more severe cases of the disease, the course of treatment can be extended as prescribed by a doctor to 10 days. As part of complex therapy for severe immunodeficiency, including with a full-blown clinical picture of HIV infection (including early clinical manifestations of HIV infection and the stage of AIDS), after bone marrow implantation, 400 mg is prescribed 5 times a day.
To prevent relapses of infections caused by Herpes simplex viruses type I and II, patients with normal immune status and in case of relapse of the disease are prescribed 200 mg 4 times a day every 6 hours, course duration is from 6 to 12 months.
For the prevention of infections caused by Herpes simplex viruses type I and II in adults with immunodeficiency, the drug is recommended to be prescribed 200 mg 4 times a day every 6 hours, the maximum dose is up to 400 mg of acyclovir 5 times a day, depending on the severity of the infection.
Children: For Herpes simplex infection and prevention of this infection in patients with weakened immune defenses, children over 3 years of age receive the same dose as adults.
When treating infections caused by Varicella zoster:
Adults: the drug is prescribed 800 mg 5 times a day every 4 hours during the day and at 8-hour intervals at night. The duration of treatment is 7-10 days.
Children: for chickenpox, prescribe 20 mg/kg 4 times a day for 5 days (maximum single dose 800 mg), children from 3 years to 6 years: 400 mg 4 times a day, over 6 years: 800 mg 4 times per day for 5 days.
When treating infections caused by Herpes zoster, adults are prescribed 800 mg 4 times a day every 6 hours for 5 days.
In patients with impaired renal function. When treating and preventing infections caused by Herpes simplex in patients with creatinine clearance less than 10 ml/min, the dosage of the drug should be reduced to 200 mg 2 times a day at 12-hour intervals.
When treating infections caused by Varicella zoster in patients with creatinine clearance less than 10 ml/min, it is recommended to reduce the dosage of the drug to 800 mg 2 times a day at 12-hour intervals; with creatinine clearance up to 25 ml/min, 800 mg is prescribed 3 times a day at 8-hour intervals.
Features of application:
Use strictly as prescribed by a doctor to avoid complications in adults and children over 3 years of age. Prescribe with caution to patients with impaired renal function and elderly patients due to an increase in the half-life of acyclovir.
When using the drug, it is necessary to ensure the supply of a sufficient amount of fluid.
When taking the drug, kidney function should be monitored (blood urea and plasma creatinine levels).
Acyclovir does not prevent the sexual transmission of herpes, so during the treatment period it is necessary to abstain from sexual intercourse, even in the absence of clinical manifestations.
Due to the presence of lactose in the composition, patients with rare hereditary diseases such as galactose intolerance, lactase deficiency, glucose-galactose malabsorption should not take the drug.
Pregnancy and lactation period. Acyclovir crosses the placental barrier and accumulates in breast milk.
Use during pregnancy is only possible if the expected benefit to the mother outweighs the potential risk to the fetus. If it is necessary to take acyclovir during lactation, interruption of breastfeeding is required.
Side effects:
The drug is usually well tolerated.
From the outside gastrointestinal tract: in isolated cases - abdominal pain,...
In the blood: transient slight increase in the activity of liver enzymes, rarely - a slight increase in urea and creatinine levels, hyperbilirubinemia, erythropenia.
From the central side nervous system: rarely - ; weakness; in some cases, increased fatigue, exhaustion, drowsiness, insomnia, confusion,
An enhanced effect is observed with the simultaneous administration of immunostimulants.
Contraindications:
Increased sensitivity to acyclovir, ganciclovir or any excipient of the drug.
Taking the drug is contraindicated during lactation.
Children under 3 years of age (for this dosage form).
Galactose intolerance, lactase deficiency, glucose-galactose malabsorption.
Carefully. Pregnancy; elderly people and patients receiving large doses, especially against the background of; renal dysfunction; neurological disorders or neurological reactions to taking cytotoxic drugs (including in history).
Overdose:
No cases of overdose have been reported after oral administration acyclovir.
Storage conditions:
List B. In a dry place, protected from light, at a temperature not exceeding 25 °C. Keep out of the reach of children. Shelf life - 2 years. Do not use after expiration date.
Vacation conditions:
On prescription
Package:
Tablets 400 mg. 5, 10, 12, 15, 20 or 30 tablets per blister pack. 1, 2 or 3 blister packs with instructions for use are placed in a cardboard pack.
Surely many are familiar with such an unpleasant rash as herpes. According to experts, this is a skin disease of viral origin. It is characterized by rashes in the form of blisters on the mucous membranes and skin.
Many believe that such a disease occurs due to a person’s decline. But this is only one of the reasons for the development of herpes.
It is imperative to fight a viral disease. Otherwise, it will spread, capturing ever larger and large areas mucous membranes or skin. Moreover, herpes is a contagious disease.
Most patients are afraid to take antiviral pills, which help eliminate this disease. They explain their behavior by the fact that such a medicine not only treats herpes, but also negatively affects other organs and systems. Experts say that if the recommended dosages are followed, anti-herpes drugs are absolutely safe.
The most popular medication used to eliminate herpetic rashes is Acyclovir Forte (400 mg). Instructions for use, consumer reviews, properties medicine and its composition will be presented below.
Composition, description, release form and packaging
In what form is the drug “Acyclovir Forte” (400 mg) produced? Consumer reviews report that this medicine is sold in tablet form. They have an oblong and biconvex shape, White color, rounded ends and scoring on one side.
The active substance of this drug is acyclovir. The medication also contains auxiliary ingredients in the form of potato starch, lactose (milk sugar), povidone, sugar (sucrose) and magnesium stearate.
This medicine is sold in blister packs and packs of thick paper.
Pharmacological characteristics
What are Acyclovir Forte tablets (400 mg)? Instructions and reviews say that this is an antiviral agent. It is classified as a synthetic analogue of purine acyclic nucleoside, which has a highly selective (negative) effect on herpes viruses.
Under the influence of viral thymidine kinase, a series of sequential reactions transforming acyclovir into di-, mono- and triphosphate of acyclovir takes place inside cells infected with a virus. The latter, being integrated into the viral DNA chain, helps block its synthesis through DNA polymerase.
According to the instructions, this drug is very effective against the herpes simplex virus (types I and II) and herpes zoster. Also, high concentrations of the drug are necessary to inhibit the Epstein-Barr virus.
Kinetic properties
Where is the absorption of the drug "Acyclovir Forte" (400 mg)? Instructions for use (tablets for herpes and other viruses should only be prescribed by an experienced doctor) states that after oral administration, this drug is absorbed from the digestive system.
The biological availability of the product in question is 15-30%. The medication penetrates well into the patient’s tissues and organs, including skin and the brain.
The binding to plasma proteins is 9-33%, and the concentration in the cerebrospinal fluid is approximately 50%.
This drug penetrates the placental barrier and also accumulates in mother's milk. The highest concentration of the drug in the blood is observed after 1.5-2 hours.
Metabolism of the drug occurs in the liver. In this case, pharmacologically inactive derivatives of 9-carboxymethoxymethylguanine are formed.
The half-life of the drug in adults with normal operation kidneys is 3 hours. In patients with severe renal failure, this period varies within 20 hours, and with hemodialysis - 6 hours. In this case, the concentration active substance in plasma decreases to 60% of the initial value.
Approximately 84% of the drug is excreted unchanged through the kidneys and 14% as a metabolite. Less than 2% of the drug is excreted from the patient's body through the intestines.
Indications for use
In what cases is a patient prescribed the medication “Acyclovir Forte” (400 mg)? The instructions for children and adults prescribe the use of the drug in the following situations:
- For the prevention of exacerbations of recurrent infections caused by herpes simplex types I and II in people with normal immune system function.
- For the treatment of infections of the skin and mucous membranes caused by herpes simplex types I and II (including primary and secondary, as well as genital herpes).
- As part of a combination treatment for people with severe immunodeficiency: in patients who have undergone bone marrow transplantation and in patients with HIV infections.
- For the treatment of recurrent and primary infections that are caused by Varicella zoster (herpes zoster virus or chickenpox).
- For the prevention of recurrent and primary infections caused by herpes simplex type I and II in patients with immunodeficiency.
Contraindications
When should a patient not be prescribed Acyclovir Forte (400 mg)? The instructions indicate that this drug has a negative effect on a person if he or she has increased individual sensitivity to ganciclovir, acyclovir or any additional ingredient.
This drug is also contraindicated for nursing mothers. It is not prescribed to children under 3 years of age with lactase deficiency, galactose intolerance and glucose-galactose malabsorption.
Special attention
With particular caution, the medication in question is prescribed to elderly people and people receiving large dosages due to dehydration, neurological disorders, impaired renal function and neurological reactions to taking cytotoxic drugs (including a history).
It should also be borne in mind that the active substance of this medication penetrates the placental barrier. Therefore, Acyclovir Forte should be prescribed during pregnancy with extreme caution.
The drug "Acyclovir Forte" (400 mg): instructions for use
For herpes and others viral diseases This medication is taken orally only. Tablets are taken during or immediately after a meal and washed down with a sufficient amount of liquid.
The dosage regimen for this medication is set to: individually(depending on the severity of the disease).
When treating infections of the mucous membranes and skin caused by herpes simplex types I and II, adult patients are prescribed the drug 200 mg five times a day for five days. It is advisable to take the drug at 4-hour intervals during the day and at 8-hour intervals at night.
In case of severe illnesses, the course can be extended as prescribed by the doctor to 10 days. As part of combination therapy for immunodeficiency, HIV infection, and also after bone marrow implantation, it is recommended to take the drug in doses of 400 mg with the same frequency.
To prevent relapses, for people with normal immunity and in case of relapse of the disease, tablets are prescribed 200 mg four times a day every six hours. The duration of this course is 6-12 months.
How should a child take Acyclovir Forte (400 mg)? The instructions for children (reviews of the medicine are presented below) recommend giving the drug in the same dosage as adults for the prevention of diseases.
When treating the virus, adults are prescribed 800 mg of the drug five times a day every 4 hours during the day and with an 8-hour interval at night. The duration of therapy is 7-10 days.
When treating Herpes zoster, adult patients are prescribed 800 mg of the drug four times a day every six hours for five days.
Side effects
Acyclovir Forte (400 mg) is tolerated quite well by patients. Although in some cases it can cause the following undesirable effects:
- hyperbilirubinemia, transient (slight) increase in liver enzyme activity, leukopenia, slight increase in creatinine and urea levels, erythropenia;
- nausea, abdominal pain, vomiting, diarrhea;
- itching, skin rash, Stevens-Johnson syndrome, urticaria, erythema multiforme, fever;
- headache, exhaustion, weakness, tremor, confusion, dizziness, drowsiness, fatigue, insomnia, hallucinations, paresthesia, agitation, decreased concentration;
- alopecia, peripheral edema, lymphadenopathy, blurred vision, myalgia, malaise.
Cases of overdose
What symptoms occur when taking increased doses of the drug “Acyclovir Forte” (400 mg)? The instructions state that to date there have not been a single case of overdose with this drug. Although experts believe that this phenomenon can lead to increased adverse reactions.
Drug interactions
Is it possible to take Acyclovir Forte tablets (400 mg) together with other medications? The prescribing information states that concomitant use of this medication with probenecid increases the mean half-life and reduces clearance active substance the drug in question.
When combined with nephrotoxic drugs, the risk of kidney problems increases.
An increase in the effect of the drug is observed when it is combined with immunostimulants.
What do you need to know before taking Acyclovir Forte tablets (400 mg)? The instructions for use state that during treatment with this drug the patient should be provided with a large amount of fluid.
Reception of this medicine does not prevent sexual transmission of the herpes virus. In this regard, during the treatment period you should abstain from sexual intercourse, including in the absence of clinical symptoms.
Drug analogues
What can replace Acyclovir Forte tablets (400 mg)? The instructions for use do not answer this question. To find out, you should contact an experienced specialist.
According to doctors, drugs such as Zovirax, Valacyclovir, Virolex, Acyclovir Akos, Acyclovir Belupo and others help against herpetic rashes.
Composition and release form
Tablets - 1 tablet: acyclovir 400 mg.
10 pieces. - contour cell packaging (2) - cardboard packs.
pharmachologic effect
Antiviral agent, a synthetic analogue of purine nucleoside.
It has the ability to inhibit in vitro and in vivo Herpes simplex virus types 1 and 2, Varicella zoster virus, Epstein-Barr virus, cytomegalovirus. In cell culture, acyclovir has the most pronounced antiviral activity against Herpes simplex virus type 1, followed in descending order of activity by: Herpes virus type 2, Varicella zoster virus, Epstein-Barr virus and cytomegalovirus. The inhibitory effect of acyclovir on these viruses is characterized by high selectivity.
Acyclovir is not a substrate for the thymidine kinase enzyme in uninfected cells, therefore acyclovir is of low toxicity to mammalian cells. High selectivity of action and low toxicity to humans are due to the absence of the necessary enzyme for the formation of acyclovir triphosphate in intact cells of the macroorganism.
Thymidine kinase of cells infected with Herpes simplex viruses types 1 and 2, Varicella zoster virus, Epstein-Barr virus or cytomegalovirus converts acyclovir to acyclovir monophosphate, a nucleoside analogue, which is then sequentially converted to diphosphate and triphosphate by the action of cellular enzymes. Acyclovir triphosphate is incorporated into the viral DNA chain and blocks its synthesis through competitive inhibition of viral DNA polymerase. Thus, “defective” viral DNA is formed, which leads to suppression of the replication of new generations of viruses.
When treating herpes, it prevents the formation of new rash elements, reduces the likelihood of skin dissemination and visceral complications, accelerates the formation of crusts, and reduces pain in the acute phase of herpes zoster.
In patients with severe immunodeficiency, long-term or repeated courses of acyclovir therapy may lead to the emergence of resistant strains, so further treatment with acyclovir may be ineffective. The majority of isolated strains with reduced sensitivity to acyclovir had a relatively low content of viral thymidine kinase and a disorder in the structure of the viral thymidine kinase or DNA polymerase. The effect of acyclovir on strains of the Herpes simplex virus in vitro can also lead to the formation of strains less sensitive to it. A correlation has not been established between the sensitivity of Herpes simplex virus strains to acyclovir in vitro and the clinical effectiveness of the drug.
Pharmacokinetics
When used externally, systemic absorption is minimal.
Clinical pharmacology
Antiviral drug.
Indications for use
Treatment of infections of the skin and mucous membranes caused by the Herpes simplex virus types 1 and 2, including primary and recurrent genital herpes; prevention of relapse of infections caused by Herpes simplex virus types 1 and 2 in patients with normal immune status; prevention of infections caused by Herpes simplex virus types 1 and 2 in patients with immunodeficiency; treatment of primary and recurrent infections caused by the Varicella zoster virus - chickenpox and herpes zoster (early treatment of herpes zoster with acyclovir has an analgesic effect and can reduce the incidence of postherpetic neuralgia).
Contraindications for use
Hypersensitivity to acyclovir, valacyclovir; lactation period (breastfeeding); children under 3 years of age (for oral administration); lactase deficiency, lactose intolerance, glucose-galactose malabsorption (for dosage forms containing lactose).
With caution: chronic renal failure; conditions accompanied by dehydration (including vomiting, diarrhea); pregnancy.
Use during pregnancy and children
The use of acyclovir during pregnancy is possible in cases where the expected benefit to the mother outweighs the potential risk to the fetus.
After taking acyclovir orally at a dose of 200 mg 5 times a day, its concentration in breast milk ranges from 60% to 410% of the plasma concentration. At such concentrations in breast milk, infants breastfeeding, can receive acyclovir at a dose of up to 0.3 mg/kg/day. Considering this fact If systemic use of acyclovir is necessary, breastfeeding should be discontinued during treatment.
Use in children
Orally for children over 2 years old - 200-400 mg 3-5 times a day, if necessary - 20 mg/kg (up to 800 mg per dose) 4 times a day. In children under 2 years of age, use a dose equal to half the dose for adults. Duration of treatment is 5-10 days.
Side effects
Determination of the frequency of adverse reactions: very often (≥1/10), often (≥1/100,<1/10), нечасто (≥1/1000, <1/100), редко (≥1/10 000, <1/1000) и очень редко (<10 000), частота неизвестна (частоту возникновения нельзя определить на основании имеющихся данных).
For oral administration
From the immune system: rarely - anaphylaxis.
From the digestive system: often - nausea, vomiting, diarrhea, abdominal pain; rarely - a transient increase in the activity of liver transaminases and bilirubin concentration; very rarely - hepatitis, jaundice.
From the nervous system: often - headache, dizziness; very rarely - psychotic disorders, tremor, ataxia, dysarthria, convulsions, encephalopathy, coma, hallucinations, drowsiness, agitation, confusion, paresthesia.
From the urinary system: rarely - a transient increase in the concentration of urea and creatinine in the blood plasma; very rarely - acute renal failure, renal colic.
From the respiratory system: rarely - shortness of breath.
From the skin and subcutaneous tissues: often - rash, incl. photosensitivity, skin itching; infrequently - urticaria, rapid diffuse hair loss (since this type of hair loss is associated with various diseases and medications, the relationship between this event and taking acyclovir is uncertain); rarely - angioedema; very rarely - exudative erythema multiforme, incl. Stevens-Johnson syndrome, Lyell's syndrome.
From the hematopoietic system: very rarely - anemia, leukopenia, thrombocytopenia.
Other: often - fever, fatigue; rarely - malaise.
Drug interactions
Drugs that block tubular secretion (for example, probenecid and cimetidine) - it is possible to increase the concentration of acyclovir in the blood plasma, increase the AUC of acyclovir, and reduce its renal clearance. However, no dose adjustment is required due to the wide range of therapeutic doses of acyclovir.
Mycophenolate mofetil - increased AUC of acyclovir and the inactive metabolite mycophenolate mofetil.
Dosage
The drug can be taken with food, since food intake does not significantly impair the absorption of acyclovir.
Adults
Treatment of infections caused by Herpes simplex virus types 1 and 2
In case of severe immunodeficiency (for example, after bone marrow transplantation) or in case of impaired absorption from the intestine, the dose of acyclovir can be increased to 400 mg. As an alternative, the use of acyclovir by IV infusion may be considered.
Treatment should begin as soon as possible after infection occurs; in case of relapses, it is recommended to prescribe acyclovir already in the prodromal period or when the first elements of the rash appear.
Prevention of relapse of infections caused by Herpes simplex virus types 1 and 2 in patients with normal immune status
In some cases, lower doses of acyclovir are effective - 200 mg 3 times / day (every 8 hours) or 200 mg 2 times / day (every 12 hours).
Some patients may experience exacerbation of infection when taking a total daily dose of 800 mg.
Treatment with acyclovir should be periodically interrupted for 6-12 months to identify possible changes in the course of the disease.
Prevention of infections caused by Herpes simplex virus types 1 and 2 in immunocompromised patients
In case of severe immunodeficiency (for example, after bone marrow transplantation) or in case of impaired absorption from the intestine, the dose of acyclovir can be increased to 400 mg 4 times a day. As an alternative, the use of acyclovir by IV infusion may be considered.
The duration of the preventive course of therapy is determined by the length of the period when there is
risk of infection.
Treatment of primary and recurrent infections caused by the Varicella zosler virus - chickenpox and herpes zoster
In cases of severe immunodeficiency (for example, after bone marrow transplantation) or in cases of impaired absorption from the intestine, the use of acyclovir in the form of intravenous infusion should be considered.
The drug should be prescribed as soon as possible after the onset of infection, because in this case, treatment is more effective.
Children aged 3 years and older
Treatment of infections caused by Herpes simplex virus types 1 and 2; prevention of infections caused by Herpes simplex virus types 1 and 2 in patients with immunodeficiency
Acyclovir is used in the same doses as for adults.
Treatment of chickenpox
Children aged 6 years and older - 800 mg 4 times a day; at the age of 3 to 6 years - 400 mg 4 times a day per day. More precisely, the dose can be determined at the rate of 20 mg/kg body weight (but not more than 800 mg) 4 times/day. The course of treatment is 5 days.
Prevention of recurrence of infections caused by Herpes simplex virus types 1 and 2; treatment of herpes zoster
There are no data on dosage regimen.
Elderly patients
The dose of the drug should be adjusted depending on the degree of renal failure.
It is necessary to ensure that adequate water balance is maintained.
Patients with impaired renal function
Acyclovir should be prescribed with caution. It is necessary to ensure that adequate water balance is maintained.
In patients with renal failure, oral administration of acyclovir in recommended doses for the treatment and prevention of infections caused by Herpes simplex virus types 1 and 2 does not lead to the accumulation of the active substance to concentrations exceeding the established safe level. However, in patients with CC<10 мл/мин дозу ацикловира рекомендуется уменьшить до 200 мг 2 раза/сут (каждые 12 ч).
When treating chickenpox and herpes zoster, the recommended doses of acyclovir are:
QC< 10 мл/мин - 800 мг 2 раза/сут (каждые 12 ч);
CC 10-25 ml/min - 800 mg 3 times/day (every 8 hours).
Overdose
Data on drug overdose are not provided.
Precautionary measures
It should be taken into account that when using acyclovir, acute renal failure may develop due to the formation of sediment from acyclovir crystals, which is especially likely with rapid intravenous administration, simultaneous use of nephrotoxic drugs, in patients with impaired renal function and with insufficient water load.
When using acyclovir, it is necessary to monitor renal function (determining the level of urea nitrogen in the blood and creatinine in the blood plasma).
Treatment of elderly patients should be carried out with a sufficient increase in water load and under the supervision of a physician, because in this category of patients, T1/2 of acyclovir increases.
When treating genital herpes, you should avoid sexual intercourse or use condoms, because the use of acyclovir does not prevent transmission of the virus to partners.
