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Geviran is a systemic antiviral drug.
Indications of the gevirana
It is applied for:
- elimination of skin infections and infectious processes on mucous membranes, provoked by the virus of ordinary herpes (this includes the genital form of herpes primary or recurrent type);
- suppression (prevention of recurrence) of infectious processes provoked by the virus of normal herpes in people with normal immune parameters;
- prevention of the emergence of infections that develop due to the herpes simplex virus in people with immunodeficiency;
- elimination of infectious pathologies arising from the varicella-zoster virus (herpes zoster and chickenpox).
Pharmacodynamics
Acyclovir is an artificial analogue of a purine nucleoside that depresses in vitro and in vivo conditions the replication of dangerous for the human body viruses from the Herpes category: common herpes of the 1st and 2nd type, as well as the varicella-zoster virus.
The effect of acyclovir on the slowing of replication of the viruses described above is sufficiently selective. Inside the disease-free cells there is no substratum of internal thymidine kinase, as a result of which the poisoning effect of the substance on cells becomes insignificant. But TCs that are viral in nature (HSV viruses, as well as VZV) phosphorylate the active drug component in the monophosphate derivative (is an analogue of the nucleoside), and it is further phosphorylated by cell enzymes in di-, as well as tri-phosphatacyclovir. The last element is a substrate for DNA polymerase of the virus, which helps it enter the DNA of the virus, which completes the binding of the DNA chain of the virus and inhibits the process of its replication.
Long-term use of acyclovir or the use of repeated courses in people with severe immunodeficiency can provoke the emergence of viral strains that are resistant to acyclovir. Within most of the noted strains with reduced sensitivity, there is some deficit of the TK element, but in addition strains that have altered the viral TK or DNA polymerase are also described.
In vitro tests have shown the ability to form strains of HSV having a reduced sensitivity index. It is not known whether there is a relationship between the presence of sensitivity in the herpes virus against acyclovir, which was detected in vitro, and also by the drug response to therapy.
Pharmacokinetics
Part of the acyclovir is absorbed from the digestive tract. The level of the average equilibrium peak concentration with the use of drugs at a dosage of 200 mg with a periodicity of 4 hours is 3.1 μmol / L (or 0.7 μg / ml), and the similar minimum level is 1.8 μmol / L (or 0.4 μg / ml). When using the drug at a dosage of 400 or 800 mg with a periodicity of 4 hours, the equilibrium mean peak values reach 5.3 μmol / L (or 1.2 μg / ml), as well as 8 μmol / L (or 1.8 μg / ml) , and the minimum values are 2.7 μmol / L (or 0.6 μg / ml), as well as 4 μmol / L (or 0.9 μg / ml).
The half-life of the substance from the plasma is approximately 2.9 hours. Most of the medicine is excreted unchanged with urine. The parameters of clearance of acyclovir in the kidneys are much higher than the analogous values of CC, which allows us to conclude that the involvement of tubular secretion and glomerular filtration in the processes of excretion of drugs with urine. The most basic product of the disintegration of acyclovir is 9-carboxymethoxymethyl guanine excreted in the urine in the amount of approximately 10-15% of the dose used.
The use of 1 g of probenicide for 1 hour before using acyclovir prolongs the half-life of the latter by 18%, and increases the AUC value inside the plasma by 40%.
The half-life of the drug from the plasma is 3.8 hours.
In persons with kidney failure in the chronic stage, the half-life of the active drug component is 19.5 hours. In hemodialysis procedures, this indicator is reduced to 5.7 hours. When dialysis, the plasma values of the substance are reduced by 60%.
The level of acyclovir inside the cerebrospinal fluid is approximately 50% of its plasma index. Synthesis of a substance with a plasma protein is rather weak (about 9-33%), because of which there is no competitive replacement of the component with other drugs from the synthesis site.
Use of the gevirana during pregnancy
Postmarketing drug tests, which contain acyclovir, revealed that the pregnant women taking this substance developed disorders. The results of these tests showed that the incidence of the occurrence of defects in the development of children whose mothers consumed acyclovir did not arise in comparison with the general indices. It was not possible to determine the relationship between the use of acyclovir in pregnant women and the appearance of congenital anomalies in newborns.
The administration of acyclovir is allowed only in cases where the probable benefit for a woman is higher than the appearance of negative reactions in the fetus.
When lactating, use the substance carefully, taking into account possible risks for the baby.
Side effects of the gevirana
Use of the medicine may cause the following side effects:
- lymphatic and systemic blood flow reactions: development of thrombocytopenia or anemia, as well as a decrease in the number of leukocytes;
- Immune disorders: occurrence of anaphylactic manifestations;
- problems with the psyche and reactions of the NS: the appearance of tremors, headaches, hallucinations, seizures and dizziness. In addition, there are feelings of confusion, excitement, drowsiness, and psychotic manifestations. Dysarthria, encephalopathy, ataxia and coma are also developing. Such signs are often temporary and usually occur in people with functional renal disorders or other factors favorable for the development of pathologies;
- problems with the functioning of the respiratory system: development of suffocation;
- reactions of the gastroenterological system: the appearance of abdominal pain, nausea, diarrhea and vomiting;
- disorders in the hepatobiliary system: the development of jaundice or hepatitis, as well as a transient increase in bilirubin or transaminase activity of the liver;
- dermatological reactions: the appearance of rashes or itching, and in addition the development of urticaria, photophobia, Quincke edema and accelerated alopecia generalized type. Because the cause of the development of the last violation may be various pathologies and the use of different drugs, it can not be said with certainty that the use of acyclovir causes alopecia;
- disorders of renal function and the work of urination: pain in the kidneys, increased serum urea and creatinine, and in addition, kidney failure in the acute stage. Kidney pain can be caused by crystalluria or kidney failure. It is necessary to monitor the hydration parameters of the patient. Functional renal disorders often go away after restoring the balance of the fluid within the body, either after reducing the dosage of the drug or canceling it;
- systemic manifestations: an increase in temperature or a feeling of fatigue.
Dosing and administration
Geviran's tablet should be swallowed whole, while washing it with water. In case of using the drug in large doses, it is required to monitor the hydration indices of the organism.
For adults.
When eliminating the infectious processes that have arisen as a result of the herpes simplex virus, it is required to take the drug in a dosage of 200 mg 5 times a day, observing approximately 4-hour interval between receptions (except for the night period). The period of therapy lasts 5 days, but with a severe degree of primary infectious disease, it can be prolonged.
People with severe immunodeficiency (eg, after bone marrow transplantation) or with reduced intestinal absorption are allowed to double the dosage of LS to 400 mg or to administer the appropriate dose IV method.
The course of therapy should be started as soon as possible after the onset of infection. With herpes simplex, it is best to start therapy during the prodromal period or after the appearance of the first symptoms of skin lesions.
In the prevention of the development of relapses (the so-called suppressive treatment) of infectious pathologies that have arisen as a result of the herpes simplex virus, people with healthy immunity need to take a medicine in the amount of 200 mg four times a day, observing 6-hour intervals between receptions. There is also a more convenient regimen - twice daily 400 mg Geviran, with a 12-hour interval.
The treatment regimen will also be effective with a dosage reduction of up to 200 mg with a triple intake per day (intervals of 8 hours) or a 2-fold use (12-hour interval).
In some patients, noticeable improvement in the condition is observed with a daily dosage of 800 mg.
To determine the possible changes in the natural course of the pathology, treatment with periods is interrupted (with an interval of six months or a year).
In the prevention of the emergence of infectious diseases due to the common herpes virus, people with immunodeficiency need to take the medicine in a dosage of 200 mg, four times a day at intervals of 6 hours.
The duration of such prevention depends on the duration of the risk period.
When treating the herpes zoster and chickenpox, you should take the medicine in a dosage of 800 mg 5 times a day at intervals of 4 hours (excluding night time). The period of therapy lasts 1 week.
People with severe immunodeficiency (eg, after bone marrow transplantation) or with reduced intestinal absorption are encouraged to use Geviran in a dosage form intended for IV injections.
For children.
When eliminating or preventing infectious diseases that have developed due to the herpes simplex virus, for children who suffer from immunodeficiency (age over 2 years), similar dosages are used by adults.
When treating chickenpox in children older than 6 years - take 800 mg of LS four times a day. Children 2-6 years old should take 400 mg of medication four times a day. The duration of the course is 5 days.
To more accurately calculate the dosage, you need to take into account the weight of the child - 20 mg / kg per day (but not more than 800 mg per day). The daily dose is divided into 4 separate doses.
People with kidney failure.
Care is needed when using in people with kidney failure. It is necessary to observe the required level of hydration inside the body.
During treatment and prophylaxis of infectious pathologies provoked by the virus of common herpes simplex in people with kidney deficiency in severe form (with CC values less than 10 ml / minute) it is required to use a dosage of 200 mg (reception twice a day with an interval of about 12 hours between applications ).
During the treatment of infectious diseases caused by the varicella-zoster virus (shingles of the form of herpes and chickenpox) in people with significantly reduced immunity: when the kidneys are in severe form (with CC values less than 10 ml / minute), take 800 mg twice a day at intervals of approximately 12 hours. If the kidneys are of moderate type (QC values within 10-25 ml / minute), 800 mg three times a day at intervals of about 8 hours.
Overdose
The substance of acyclovir is partially absorbed from the digestive tract, but its one-time use in dosage up to 20 g does not lead to intoxication. Sometimes, when taking drugs during the 7th day, there were such manifestations of an overdose: from the gastrointestinal tract - vomiting with nausea, and from the NA - sensation of confusion and headaches. Such neurological disorders as the appearance of hallucinations, seizures, sensations of agitation or confusion, as well as the state of coma, were also observed in the case of an overdose after using drugs in the form of an injection.
When taking a medicine in a large dose, it is necessary to follow the patient regarding the development of signs of intoxication. If they occur, symptomatic therapy is required. The procedure of hemodialysis helps to accelerate the excretion of the active component of the drug from the blood, so it is allowed to use it in case of poisoning.
Interactions with other drugs
Excretion of acyclovir mainly occurs in unchanged form - through the tubules of the kidneys. Combination with drugs that are converted inside the body in the same way, can lead to an increase in the plasma values of acyclovir.
Cimetidine with probenecid can increase the AUC of acyclovir, and in addition to lower the level of its clearance within the kidneys.
A similar increase in the plasma values of acyclovir with an inactive decay product, mycophenolate mofetil (an immunosuppressive agent used after organ transplantation) developed in the case of combined use of drug data. But, since acyclovir has a large drug range, dosage adjustment is not required.
Attention!
To simplify the perception of information, this instruction for use of the drug "Geviran" translated and presented in a special form on the basis of the official instructions for medical use of the drug. Before use read the annotation that came directly to medicines.
Description provided for informational purposes and is not a guide to self-healing. The need for this drug, the purpose of the treatment regimen, methods and dose of the drug is determined solely by the attending physician. Self-medication is dangerous for your health.