Acyclovir is a popular antiviral drug. It is widely used in various fields of medicine for the treatment of viral pathologies. The pronounced therapeutic effect makes it possible to improve well-being in a short time. The presence of various forms of release extends the application.
Composition and forms of release
The main active ingredient of the drug is acyclovir. Its mass fraction depends on the form of release: the ointment contains 50 mg, the eye ointment contains 30 mg, 50 mg per 1 gram of cream, 200 or 400 mg per tablet, and 250, 500 or 1000 in a bottle. Determined by the manufacturer.
Among the dosage forms that can be purchased, there are:
- tablets in the amount of from 10 to 100 pcs. packaged;
- lyophilisate in a bottle made of glass;
- eye ointment in a tube with a volume of 2 to 5 grams;
- ointment or cream in a tube from 2 to 30 grams.
pharmachologic effect
Acyclovir is an antiviral drug.
Pharmacodynamics
The main active ingredient of the drug is a synthetic analogue of purine nucleosides that inhibit the replication of virus strains that cause chickenpox or shingles, as well as cytomegalovirus, Epshina-Barr virus or type 1 or herpes.
Thymidine kinase, which is an enzyme of the viral particle, converts acyclovir to monophosphate. Subsequently, sequential processes of phosphorylation take place and triphosphate is formed. This form leads to the inhibition of DNA replication in the virus particle. Gradually, viral cells cease to multiply and die.
Against the background of herpes, new rashes are no longer formed, which reduces the risk of complications from internal organs. External formations heal faster, and also decreases pain in the acute course of shingles. To a small extent, an immunostimulating effect is achieved.
Pharmacokinetics
Pharmacokinetics depends on the form of the drug.
Tablets and injections
When taking pills a small percentage of absorption is noted due to low lipophilicity. Bioaccessibility of Acyclovir is 30% for oral use. This concentration is sufficient for therapeutic effect. Bioavailability decreases with increasing dosage. Food intake will not affect absorption. The maximum concentration is fixed after 1.5-2 hours after administration.
Oral and injection methods of use contribute to the penetration of the drug through tissue barriers to the brain or placenta. In humans, it can be found in all organs. The possibility of getting into breast milk is taken into account when prescribing Acyclovir to lactating women. Excretion is carried out through the intestines or kidneys.
A decrease in blood concentration occurs only after procedures such as hemodialysis. Chronic renal failure reduces the rate of elimination of the drug.
Ointment
When applying the ointment, absorption into the systemic circulation is not observed, only a local effect develops. It can not be detected in the serum. Insignificant absorption is possible if there is serious damage to the skin.
Eye ointment
When using eye ointment, the active substance is concentrated in the intraocular fluid. A therapeutically insignificant amount can be detected in the urine.
Indications for appointment
Indications for use are directly dependent on the dosage form.
Pills
Oral administration is prescribed for therapeutic and prophylactic purposes in the presence of symptoms of a primary, secondary viral process, which is caused by the herpes simplex causative agent, shingles, and chickenpox.
It is used as a prophylaxis of viral diseases in patients with HIV or after transplantation.
Ointment
Topical ointment applied for the treatment of:
- Herpes of any type, accompanied by the appearance of skin rashes.
- The appearance of a viral infection caused by shingles or chicken pox.
Eye ointment
Its use is indicated for the elimination of herpetic eruptions on the surface of the conjunctiva or cornea.
Infusion solution
The use of the solution is prescribed to eliminate the signs of viral diseases in patients with immunodeficiency, newborns or persons who have undergone transplantation.
A combination of several dosage forms for the treatment of pathology, in particular, and local and systemic drugs.
Popular analogues
There are a large number of funds that are analogues of Acyclovir. These drugs may have a different composition or mechanism of action.
Valtrex
Valaciclovir in the form of hydrochloride is contained as the main active ingredient. Valtrex is available in a single pill form. This explains the ease of use and dosing. Valacyclovir is a more complex acyclovir ester and has an antiviral effect. The tool has a high percentage of bioavailability. It is allowed for use by persons over the age of twelve.
Among the main indications are the presence of diseases caused by the herpes simplex virus in various clinical forms, as well as cytomegalovirus. The drug can be prescribed and for prophylactic purposes. Currently, the tool has received more widespread use compared with Acyclovir due to a more pronounced therapeutic effect.
Herperferon
Means, produced in the form of ointment, has antiviral, immunomodulatory, anti-inflammatory, as well as analgesic effect. Its composition is combined, since in addition to acyclovir, the presence of interferon alpha and lidocaine is distinguished. Among the indications for use is the presence of local manifestations of primary or recurrent herpes, localized in the area of the lips and genitals, as well as herpes zoster.
Means shows the expressed therapeutic effect and differs in convenience of dosing. In rare cases, it causes the development of side reactions in the form of desquamation. Restriction of reception is connected with a narrow range of application, and also lack of possibility of system use.
Zovirax
The tool is available in various forms, among which emit an ointment, cream, lyophilisate or tablets. The main active ingredient is acyclovir. It is able to have an antiviral effect. Its mechanism of action, as well as its pharmacokinetic properties, are similar to acyclovir. The drug fights with herpes simplex pathogens of various kinds. It is allowed to use for the treatment of children who are under two years old. At the same time, only half of the average therapeutic dose should be consumed.
For newborns, it is possible to use for the treatment of the manifestations caused by the herpes simplex virus, and also as a prophylaxis in the presence of signs of herpetic lesions of the genital organs during birth. The cost of Zovirax exceeds the price of Acyclovir, which explains the low percentage of its use.
Valaciclovir
Domestic drug exhibiting antiviral effect. The basis of the tool is the same name component. You can buy it only in tablet form. Among the main indications against which it is possible to achieve a therapeutic effect, they distinguish the infection with herpes simplex, shingles, and cytomegalovirus. Prophylactic use is indicated during the period of transplantation or to prevent the recurrence of any viral disease.
The tool is forbidden to use in patients with severe HIV. With non-compliance with the dosing regimen, as well as when applying against the background of existing contraindications may develop severe side effects. The drug is an analogue of Valtrex.
Contraindications to use
Among the contraindications for which it is forbidden to use the drug in any form, there are:
- increased sensitivity of the body to the main active ingredient. For individual forms, excipients included in the composition that can lead to the development of an allergic reaction are taken into account;
- history of an allergic reaction to the use of Valaciclovir;
- age less than two years;
- breastfeeding period (especially for injection and oral release).
Particular caution should be exercised when using the drug during pregnancy at any time, as well as in the presence of signs of damage to the nervous system or renal failure. This is due to possible neurotoxic or nephrotoxic effects. This group includes signs of dehydration or neurological disorders in response to cytotoxic drugs.
