How does acyclovir

Acyclovir - is an antiviral drug, providing virostatic action (suspend livelihoods viruses). Available acyclovir in different dosage forms: tablets for oral use, in suspension for solution for injection and for external use in the form of ointments, ophthalmic ointments and creams.

Acyclovir is an analog of a natural component of the DNA so that it can be implemented actively in the metabolic processes of cells. Enzymes virus-infected cells convert acyclovir Acyclovir - as it is safe?   the active form - acyclovir triphosphate, which penetrates into the cells infected with the herpes virus, and replaces one of the natural components required for the synthesis of DNA viruses. By building in the synthesized DNA virus, acyclovir triphosphate inhibits viral replication.

The high selectivity of action, and low toxicity of this drug for humans due to the fact that in healthy, non-diseased human tissue cells with viruses have enzymes that convert acyclovir into acyclovir triphosphate active form. Therefore, the drug does not affect the normal life processes in the cell. The specificity and high selectivity also advantageous due to the accumulation of acyclovir in cells infected with herpes virus.

Acyclovir is active against herpes simplex virus types 1 and 2, the virus that causes chickenpox and shingles Shingles - from simple ailments and brain damage , Epstein-Barr virus (causing acute mononucleosis and some cancers). Moderately active against cytomegalovirus (herpes family of viruses that can affect many organs and tissues, the disease often asymptomatic). When herpes acyclovir prevents new elements disease, reduces the likelihood of infection and complications in the internal organs, promotes the formation of crusts, reduces pain in the acute phase of herpes zoster. It has immunostimulatory effects.

After oral administration of acyclovir absorbed in the small intestine and enters the bloodstream. About 15-30% of the drug gets into the tissues affected by the virus (low bioavailability). The increase in the dose only reduces the bioavailability atsiklovi? 8%. The presence of food in the digestive system does not affect absorption atsiklovi? 8%. Acyclovir breaks in the liver to form inactive metabolites that are excreted in the urine and feces. Approximately 14% of an oral dose is excreted unchanged in the urine.

Number atsiklovi? 8%, falling after topical application to the surface layer of the skin (the place of introduction of viruses into the skin cells) is 30-50% of the concentration attainable taking the drug inside.

Indications and contraindications

Acyclovir tablets for oral prescribed:

• in the treatment of infections of the skin and mucous membranes, herpes simplex virus types 1 and 2, including the primary and recurrent herpes pudendal lips and both patients with impaired immunity and with normal immune system;
• to prevent recurrent herpes cases of recurrent genital herpes in patients with a normal immune system, and with reduced immunity;
• in the treatment of infections caused by herpes viruses causing herpes zoster Ringworm - not only infectious disease   and chickenpox.

Intravenous acyclovir is indicated for herpes encephalitis (inflammation of the brain tissue), herpes infection in newborns, eczema and inflammation of the lungs.

Topical acyclovir is prescribed for topical treatment of skin infections caused by the herpes simplex viruses Herpes simplex - in fact, not so simple Including primary and recurrent herpes of the external genitalia and the mouth. In the form of eye ointment acyclovir is indicated for herpetic eye disease.

Acyclovir is contraindicated in case of hypersensitivity to the drug during pregnancy and breast-feeding the child.

Signs of overdose and side effects

In case of overdose can occur: headache, neurological disorders, shortness of breath, nausea, vomiting, diarrhea, renal failure, lethargy (a long sleep), convulsions, coma (unconsciousness, caused by a strong depression of the central nervous system). In such cases, you should immediately call an ambulance because the treatment must be carried out only in the hospital.

Side effects that may occur while taking acyclovir: allergic reactions such as skin rash, nausea, vomiting, diarrhea, abnormal liver function and kidney function, headache, dizziness, fatigue, decreased concentration, hallucinations, drowsiness or insomnia, a slight decrease in the number red blood cells and white blood cells, fever, hair loss.

With prolonged use of ointment might peeling at the site of its application, seldom - local irritation, burning sensation, pain.

When administered intravenously at the injection site may occur inflammation of the vein wall. In addition, there may be sand in the urine, confusion, lethargy, hallucinations, irritability, drowsiness, trembling of the limbs and body, seizures, psychosis, coma.

Treatment with acyclovir should be under a doctor's supervision, and as early as possible, with the appearance of the earliest signs of the disease.

Semi-synthetic antibiotics

After the structure was elucidated most natural antibiotics, began to appear attempts to make their chemical counterparts. Successful was the chemical synthesis of chloramphenicol, at present it is prepared only by chemical means. The opportunity to be the synthesis of other antibiotics, but a natural way of getting them was easier and more economical.

First, the antibiotics used in the form in which they are synthesized by microorganisms. However, as the chemistry developed methods of improving the properties of natural antibiotics by partially changing their chemical structure. These became known as semi-synthetic antibiotics. Especially great advances have been made in the preparation of semi-synthetic penicillins. The first semi-synthetic penicillin was benzylpenicillin, which is more antibacterial activity than the natural penicillin, while remaining low in toxicity. Then there were prepared, and other semi-synthetic antibiotics that possess the desired properties.

Mechanism of action

According to the mechanism of action of antibiotics on pathogens can be divided into two groups: the bacteriostatic and bactericidal action.

Bacteriostatic antibiotics in the doses used to treat, inhibit the growth of bacteria without killing them. But with increasing doses of bacteriostatic antibiotics they may be, and antibacterial properties. By bacteriostatic antibiotics include, for example, tetracycline, chloramphenicol. Their mechanism of action is in violation of the formation of the protein inside the cell pathogen.

Bactericidal antibiotics - lead to the death of microbes, these include the penicillins, cephalosporins, and others. They destroy bacterial cell walls, which leads to its death. These antibiotics are active against bacteria and propagated almost inactive against bacteria at rest.

Antifungal antibiotics affect the integrity of the fungal cell membrane, resulting in membrane loses its properties of the barrier between the cell contents and the external environment that promotes its destruction.

Antitumor antibiotics inhibit DNA synthesis of tumor cells.

Antibiotics

Antibiotics are widely used in medical practice for the treatment of various bacterial, fungal infections Fungal infection: to prevent and defeat   and tumors.

The success of treatment of bacterial infections depends on the susceptibility of the disease to the antibiotic, therefore before administration of antibiotics being identified this sensitivity using seeding a biological fluid (blood, urine, sputum, nasal secretions, etc.) on special culture media followed by exposure to these antibiotics . Since the treatment often develops addictive pathogen to Nome or antibiotic, then the treatment of chronic infections in the analysis of sensitivity to antibiotics should be repeated every two weeks, and with a decrease in antibiotic sensitivity to change. In the case of serious illness when you can not delay the treatment, initially appointed by the broad-spectrum antibiotics Broad-spectrum antibiotics - not only treat but also cripple And the final treatment is given after the determination of antibiotic sensitivity.

The destruction under the influence of antibiotics normal intestinal microflora may lead to dysbacteriosis Dysbacteriosis - what brings self   (in the gut bacteria multiply) and the lack of B vitamins B vitamins: the body useful helpers   (normal microflora produces these vitamins). Therefore, together with antibiotics usually prescribed vitamins, and after a course of antibiotic treatment restored the normal intestinal microflora.

  Galina Romanenko