Valacyclovir Canon is one of the best developments in the modern pharmaceutical industry. Experienced virologists tried to take into account absolutely all aspects that are necessary for the effective fight against various infections provoked by viruses. This medication is an effective substitute for the popular Acyclovir drug.
The composition of the drug
"Valacyclovir Canon" is sold in the form of tablets in a film coating. The main active ingredient is valaciclovir hydrochloride. Auxiliary components are also used:
- Povidone K90.
- Polysorb.
- Crospovidonum.
- Magnesium salt of stearic acid.
- MCC.
The film coating used contains titanium dioxide, polysorbate, macrogol. Tablets are sold in 6 and 10 pieces per pack.
Operating principle
The medicine "Valacyclovir Canon" belongs to the category of antiviral agents. After the first oral administration, the main component is transformed into the active metabolite acyclovir. This substance has powerful inhibitory properties against cytomegalovirus, herpes, varicella-zoster, chicken pox. The medication fully inhibits the production of the DNA of the virus, so that its structure is gradually destroyed and it stops multiplying. In such a situation, the death of a pathogenic microorganism is inevitable.
When administered orally, “Valaciclovir Canon” is perfectly absorbed from the gastrointestinal tract. A specific liver enzyme turns it into two substances - valine and acyclovir. In healthy people, a peak plasma concentration of the drug is observed 2 hours after ingestion of 500 mg. The diagnosed indicator is in the range from 10 to 36 μmol / ml. If you take 1 g of the drug once, then its final bioavailability will be equal to 50%, regardless of food intake. The maximum drug content in blood plasma is fixed for three hours, after which it gradually decreases.
In patients with normal renal function, the elimination half-life is no more than three hours. More than 85% of the drug is excreted with urine in the form of acyclovir. If the patient has previously been diagnosed with severe kidney damage, the final half-life may be 15 hours or more.
To significantly increase the bioavailability of the drug, creams and ointments with acyclovir are actively used. In such a situation, the amount of the basic substance can reach 60%, but only at the place of application of the product. The medication is intended for the treatment of genital, oral, and also herpes zoster. The drug prevents possible relapses, complications, and also helps to quickly eliminate the emerging bubble rash.
It is worth noting that viruses do not have their own cells, which is why they gradually integrate into human DNA and use biological material for their own reproduction. After that, the infected cell of the patient’s body ceases to perform its basic functions. That is why herpes is commonly called an intracellular parasite. For reproduction, this virus needs a "host" in order to be able to develop uncontrollably and infect new sites.
Indications
In the instructions for Valacyclovir Canon, manufacturers indicated that the medication is intended for the treatment and prevention of the following diseases:
- Herpes zoster.
- Significant reduction in the risk of transmitting a dangerous virus to a sexual partner.
- Herpes of the lips (the so-called "cold" on the lips and in the peridental zone).
- Effective prevention of cytomegalovirus infection during intracavitary operations (this also applies to transplantology).
- Primary stage and relapses of genital herpes.
- Prevention of the development of genital infection.
Contraindications
The drug "Valacyclovir Canon" is forbidden to use for those patients who have been diagnosed with the following diseases:
- HIV infection. The drug negatively affects the patient's body in the event that the content of CD4 lymphocytes is less than 100 / μl.
- Hypersensitivity to the components of the drug.
The medicine is not prescribed for children under 12 years of age with cytomegalovirus infection. Since experts did not conduct studies on the effect of the drug on the body of pregnant women, only doctors can prescribe the drug.
Instructions for use
"Valacyclovir Canon" in tablets is taken orally, before or after a meal. The optimal dosage is selected by specialists individually, as it all depends on the clinical picture. Therapy should be started within two days after the first signs of infection (pain, burning, itching, rash).
The treatment regimen depends on the diagnosed disease:
- Primary genital herpes. Take 1 g 2 times a day. Therapy lasts 10 days.
- Labial herpes. In the morning and evening, take 2 g of the drug. The duration of treatment is determined by the doctor.
- Recurrent genital herpes with HIV infection. To minimize the risk of transmission of pathology to a sexual partner, it is recommended to use 0.5 g 1 time per day.
- Herpes classic. In the morning and evening, take 0.5 g of the drug. The treatment lasts 2 weeks.
- Recurrent genital herpes. For three days, take 0.5 g of Valaciclovir Canon 2 times a day.
- Shingles. To achieve the maximum therapeutic effect, it is necessary to take 1 g of the drug every 8 hours. Therapy is designed for 1 week.
- If the patient is on hemodialysis, then taking the medicine is possible only after the procedure.
- Qualitative prophylaxis of cytomegalovirus infection after successful organ transplantation implies the use of 2 g of medicine 4 times a day. Treatment should last at least 3 months.
In renal failure, the optimal dosage is set in accordance with creatinine clearance. Numerous reviews about the "Valacyclovir Canon" indicate that it is better not to engage in self-medication, as this is fraught with deterioration of well-being. To avoid negative manifestations, the patient must always consult with your doctor.
Adverse reactions
Numerous reviews of the "Valacyclovir Canon" indicate that deterioration in well-being is extremely rare. Only if the patient exceeds the permissible dosage or does not study all the contraindications, is this fraught with the following negative manifestations:
- The development of acute renal failure. The patient may experience an increased reaction to sunlight, shortness of breath. Thrombocytopenia is not excluded.
- From the gastrointestinal tract: vomiting, nausea, diarrhea, loss of appetite, hepatitis, an increase in the enzymatic parameters of the liver, as well as pain in the stomach, which can give back.
- Allergic manifestations: itching, rash, urticaria, anaphylactic shock, Quincke's edema, aplastic anemia, vasculitis, cardiac arrhythmias, fever, dehydration, increased blood pressure, severe fatigue.
- Central nervous system: dizziness, constant nervous tension, poor coordination, coma, hallucinations, depression.
Available analogues
Valacyclovir Canon is highly effective, but in some cases, patients need to replace this medication. The most popular analogues include:
- Valtrex
- Valmik.
- "Vatsireks". The medication quickly acts on viral cells and eliminates pain.
Experts note that Valaciclovir Canon has at least two medicines with a similar principle of action - these are Valtrex and Acyclovir. The main difference between these drugs is as follows:
- Valtrex has a rather complex formula, due to which it can be in the patient’s body for a longer time, significantly reducing the number of receptions. Many patients choose this medication because of the wide variety of pharmaceutical forms: ampoules, creams, tablets.
- "Acyclovir" after ingestion prevents the transmission of the viral component to a healthy cell. At the final stage, in the form of decay products, it is excreted through the kidneys with urine.
If the patient decided to understand how Valacyclovir differs from Valacyclovir Canon, then it must be taken into account that the first medication directly affects the herpes virus, gradually destroys it and prevents the dangerous infection from growing further. Thanks to this, the patient can quickly cope with the pathology. Experts have proven that there is no significant difference between Valacyclovir Canon and Valacyclovir. Both medicines are used both for the comprehensive fight against herpes, and for the prevention of viral diseases.
Precautions
Doctors prescribe the drug with caution in the following cases:
- Critical dehydration.
- The presence of acute hepatic or renal failure.
- Fetal bearing and breastfeeding.
- Patients older than 60 years.
- Undergoing therapy with nephrotoxic drugs.
It is necessary to take into account the clinical condition of the patient and the specificity of the side effects of Valaciclovir Canon in assessing the patient's ability to drive a vehicle. The drug can affect mental activity, which is very important when working with mechanisms that require a quick psychomotor reaction.
Interaction with other medicines
Since Valacyclovir Canon is processed by the kidneys by channel secretion, other drugs will interfere with its stable excretion from the body. "Mycophenolate" increases the concentration of the drug in the patient's blood plasma. "Tacrolimus" and "Cyclosporin" several times increase the load on the kidneys.
special instructions
Individuals with dehydration and elderly patients during the treatment period need to increase the amount of fluid consumed, since there is a risk of developing acute renal failure. For a more effective fight against genital herpes, it is necessary to avoid sexual intercourse, since the medication cannot be used as a means to eliminate the fact of transmission of a dangerous infection.
Long-term use of the drug in high doses in conditions that are accompanied by immunodeficiency (a clinically pronounced form of HIV infection, bone marrow or kidney transplantation) is fraught with the development of dangerous thrombocytopenic purpura and hemolytic-uremic syndrome. Death is not excluded. In case of adverse reactions from the central nervous system, the drug must be canceled.
Use during pregnancy and breastfeeding
“Valacyclovir Canon” is prescribed with caution in this category of patients. Indications for use are taken into account only if the expected therapeutic effect exceeds the potential risk to the developing fetus. The data recorded by gynecologists did not show an increase in the number of birth defects.
The component acyclovir is the main metabolite of the drug, which is freely excreted along with breast milk. That is why for the period of treatment of the child must be transferred to artificial mixtures.