Acyclovir – capsules, lyophilisate, suspension, tablets

Pharmacological properties of the drug Acyclovir

Antiviral agent. Active against herpes simplex virus types 1 and 2, herpes zoster virus ( Varicella zoster ), Epstein-Barr virus and cytomegalovirus. After penetration into a cell infected with a virus, acyclovir is transformed by thymidine kinase into active acyclovir triphosphate. The latter interacts with the viral DNA polymerase and is integrated into the DNA that is synthesized for new viruses. In this way, defective viral DNA is formed, which leads to suppression of the replication of new generations of viruses. After oral administration, acyclovir is partially absorbed from the digestive tract. After intravenous administration, the half-life of acyclovir in adults is about 2.9 hours. Most of the active substance is excreted unchanged in the urine. Plasma protein binding is 9–33%. The only metabolite of acyclovir is 9-carboxymethoxymethylguanine. In patients with chronic renal failure, the half-life of acyclovir increases. The concentration of the active substance in the CSF is approximately 50% of the concentration in the blood plasma. When applied to the skin, acyclovir is not detected in the blood serum. From ophthalmic ointment, acyclovir quickly penetrates the corneal epithelium and reaches therapeutic concentrations in the intraocular fluid.

Composition and release form

The drug is available in several dosage forms:

1. ​Pills. Prescribed for the treatment of papillomas in different parts of the body. They are used orally, so they allow you to fight the main problem from the inside. After completing the course of therapy, the level of pathogenic pathogens in the body is noticeably reduced.
2. ​Ointment. Applied topically, it is effective against the most common human papillomavirus infection, which is localized on the surface of the body. The antiviral agent is applied directly on top of the warts, so there is a pronounced therapeutic effect at the local level. When the ointment is distributed on the skin, the main substance penetrates the bloodstream, preventing viral pathologies in the future.
3. ​Solution. Mainly used for chronic forms of the disease. The concentration of the drug is selected by the doctor taking into account the clinical picture and the results of an analysis for the content of viral agents in the blood. In this case, it is highly recommended not to self-medicate, so as not to provoke a worsening of the condition.

The main component is acyclovir, its content differs depending on the dosage form.

Use of the drug Acyclovir

Orally during the day with an interval of 4, 6 or 12 hours. For adults and children over 2 years of age for infections caused by the herpes simplex virus, acyclovir is prescribed 200 mg 5 times a day for 5 days; if necessary, the course of treatment is extended to 10 days. Children under 2 years of age are prescribed 1/2 the dose for adults. For the prevention of recurrent genital herpes - 400 mg 2 times a day or 200 mg 4 times, course - from 6 months to 1 year. To prevent herpetic infection in patients with immunodeficiency or after bone marrow transplantation, acyclovir is prescribed 400 mg 4 times a day during the entire period of risk of developing infection. When treating Herpes zoster oftalmicus - at a dose of 800 mg 5 times a day for 7-10 days. For chickenpox, children under 2 years old are prescribed a dose of 200 mg, from 2 to 6 years old - 400 mg, over 6 years old - 800 mg 4 times a day for 5 days (on average at the rate of 20 mg/kg body weight per dose, but not more than 800 mg). For patients with chronic renal failure with a creatinine clearance of less than 10 ml/min, acyclovir is used in a dose of 200 mg every 12 hours in the treatment of infections caused by the Herpes simplex , and up to 800 mg every 12 hours in the treatment of infections caused by the Herpes zoster . Ointment or cream (5%) for external use is applied to the affected areas of the skin 5 times a day during the daytime with an interval of 4 hours; Duration of treatment is 5–10 days. A 10 mm long column of 3% ophthalmic ointment is placed behind the lower eyelid every 4 hours, 5 times a day. The duration of treatment for ulcerative forms of keratitis is 7-10 days, interstitial - 10-12 days. Treatment should be continued for 3 days after the symptoms disappear. Acyclovir solution is administered intravenously in a slow drip over 1 hour. Adults and children over 12 years of age for infections caused by Herpes simplex (except herpetic encephalitis) or Varicella zoster are given an intravenous infusion of acyclovir at a dose of 5 mg/day. kg every 8 hours; children from 3 months to 12 years - at a dose of 250 mg/m2 every 8 hours for 5–7 days. For patients with an immunodeficiency state, patients with herpetic encephalitis or infections caused by the Varicella zoster , acyclovir is administered at a dose of 10 mg/kg body weight every 8 hours (adults and children over 12 years of age) or 500 mg/m2 every 8 hours (children aged from 3 months to 12 years) for 7–10 days. For the purpose of prevention, regardless of the type of infection and the age of the patient, intravenous infusions of acyclovir are carried out at a dose of 250 mg/m2 every 8 hours. For newborns, acyclovir is administered at the rate of 10 mg/kg body weight every 8 hours. For patients with renal failure, a dose of /infusion is set taking into account creatinine clearance: at a value of 20–50 ml/min, acyclovir at a dose of 5–10 mg/kg is administered every 12 hours; with a creatinine clearance of 10–25 ml/min, the recommended dose (5–10 mg/kg) is administered every 24 hours; if the value is less than 10 ml/min, 1/2 of the standard dose is administered every 24 hours immediately after the dialysis session.

Indications

The drug is prescribed for the treatment of the following conditions:

1. ​Infectious lesions of the skin and mucous surfaces due to herpes viruses.
2. ​Chicken pox.
3. Shingles.
4. Herpes localized in the genital area.
5. ​Primary and secondary herpes diseases in persons with immunodeficiency.
6. ​Viral pathologies among people with a normal level of immune status.

Combination with other medications

Parallel administration of the tablet form with external agents (ointments, creams) enhances the therapeutic effect. Also, recovery occurs ahead of schedule when taking Acyclovir simultaneously with drugs that stimulate the immune system and vitamins. The elimination of the active substance is slowed down with simultaneous treatment with agents to reduce the level of uric acid in the blood. It is not recommended to combine the drug with drugs that have a nephrotoxic effect.

Otherwise, the antagonism of acyclovir has not yet been sufficiently studied.

Recommendations for admission

According to indications, Acyclovir tablets are taken only orally. You should take the product with plenty of water, as dehydration may occur during therapy. As a rule, each dose of the drug should be taken with a glass of liquid.

The medication is prescribed for the following diagnoses:

• herpes infections type 1 and 2;
• chickenpox in children;
• herpes zoster in adults;
• prevention of herpes;
• prevention of cytomegalovirus;
• complex therapy of immunodeficiency virus;
• prevention of diseases after organ transplantation.

In addition to this treatment, an ointment for external use may be prescribed to speed up the healing of virus-infected skin.

Signs of overdose

The most common signs of overdose are: agitation, coma, seizures, lethargy. If the concentration of the main substance is higher than the solubility in the renal tubules, its precipitation may occur. If side effects from Acyclovir develop, symptomatic treatment is prescribed. In case of an overdose of the infusion solution, the concentration of creatinine, urea and blood nitrogen increases, and renal failure occurs. Neurological symptoms include agitation, confusion, hallucinations, convulsions, and coma. In this case, hemodialysis is prescribed.

Side effects

Taking Acyclovir in any dosage form can provoke the development of the following side effects:

1. ​Headache, even migraine.
2. ​Dizziness.
3. ​Intense aching pain in the kidney area.
4. ​Dyspeptic disorders - vomiting, feeling of nausea, stool disturbances, abdominal discomfort.
5. Shortness of breath.
6. ​Signs of an allergic reaction - skin rashes, itching. Rarely, anaphylactic shock and urticaria.
7. Systemic manifestations include fatigue, malaise, fever, tissue swelling and visual disturbances.
8. ​Increased sleepiness.
9. ​High excitability.

As a rule, the drug is quite well tolerated by patients. Side effects are observed in rare cases; patients with acute renal failure and other severe concomitant pathologies are most susceptible to them.

Therapy for pregnant women

Treatment with the drug during gestation and lactation has not yet been sufficiently studied, but it is already known for sure that the compound is able to penetrate through the placenta and milk to the baby. Instructions for the use of Acyclovir 400 tablets allow therapy in cases of urgent need, when the benefit to the mother outweighs the possible risk to the child. Of course, the decision to prescribe medication in this case can be made solely by the doctor.

A study of women who took the drug in the 1st trimester of pregnancy showed that there was no increase in the number of birth defects compared to the general population, but this data is still not enough to make a final decision.

Acyclovir analogs

Analogs of Acyclovir for the active component are:

• External agents (cream or ointment): Acyclostad, Gervirax, Zovirax, Virolex, Vivorax, Herpetad, Gerperax;
• Tablets or powder for the preparation of solution for infusion: Vivorax, Medovir, Virolex, Provirsan.

Also, if necessary, after medical consultation, it is possible to replace Acyclovir with analogues according to the mode of action: Alpizarin, Ribapeg, Giporamin, Condilin, Epigen, Gossypol, Minaker, Vartek, Erazaban, Aldara, Arviron, Vacirex, Cymevene, Rebetol, Famciclovir-Teva, Ribavirin and some other.

Drug interactions

When administered in combination with probenecid, the mean half-life increases and the clearance of the drug decreases. When taken with nephrotoxic drugs, the risk of developing renal dysfunction increases; when taken with immunostimulants, the effect of acyclovir is enhanced. When mixing solutions, the alkaline reaction of the main active element should be taken into account.

The side effects of Acyclovir Akrikhin are the same.

Exceeding the dose

According to reviews, Acyclovir in tablet form does not cause overdose attacks when taking up to 5 g of the active substance at a time. This has been proven by experts, but there is no data on taking higher concentrations of the compound. If there is a feeling of uncertainty or the body still exhibits some negative reactions, then it is better to immediately consult a specialist.

An overdose actively manifests itself when the ointment is accidentally swallowed or any other administration of the drug that bypasses the digestive tract. Signs in this case include seizures, neurological abnormalities, gastrointestinal disorders, headaches, shortness of breath, renal dysfunction and coma. Treatment is only inpatient.

General characteristics

The drug "Acyclovir" is an antiviral drug and acts on the causative agent of the disease by changing its DNA. The effectiveness of such treatment largely depends on the timely start of taking the medication.

The dosage of the Acyclovir tablet can be 0.2 g, 400 mg and 800 mg, but the latter option is quite rare. If it is necessary to take a large amount of a substance, patients often simply drink 2 pills with a concentration of 0.4 g.

The main active element of the drug is acyclovir, which is a white powder. To give it the desired shape, strength and technological qualities, additional substances are used.

The composition of the Acyclovir tablet remains the same at any dosage and includes, in addition to the active substance:

• starch;
• lactose;
• calcium stearate;
• Aerosil;
• polyvinylpyrrolidone.

The tablets have a flat-cylindrical round shape with a score on one side. Their color is always white. Some manufacturers may additionally add their imprints to the surface of the pills.

Contraindications

Obvious contraindications for Acyclovir are:

1. ​Serious heart pathologies.
2. ​Kidney diseases, especially chronic forms, acute failure.
3. ​Nervous diseases.
4. ​Increased hypersensitivity to the components of the drug.
5. ​Time of bearing a child and breastfeeding.
6. ​Children under 3 years old.

The antiviral drug is used with extreme caution in the treatment of elderly people and the presence of dehydration.