Valtrex refers to the antiviral agents of the group of nucleotide analogues. Due to its mechanism of action, pharmacokinetics and composition, it should be attributed to a group of prodrugs: it is produced in tablets and is designed to effectively combat the spread of viruses in the human body. The main active substance of Valacyclovir is valaciclovir hydrochloride. Its concentration will depend on the volume of the tablet: in some, it weighs 556 mg, and in the other, 1112 mg, respectively, these values are equivalent to the mass of Valaciclovir 500 mg and 1000 mg. In addition, the composition contains auxiliary substances, among them small amounts of cellulose, magnesium stearate, macrogoll and hypromellose.
Mechanism of Valtrex Action?
The drug is taken inside and in the gastrointestinal tract it is completely absorbed. At the stage of absorption in the intestine or in the liver, enzymatic hydrolysis of valacyclovir hydrochloride takes place with the formation of the main active ingredient acyclovir and auxiliary L-valine. The percentage of bioavailability of the drug is quite low, on average about 50%. The maximum daily concentration in the blood is reached only after at least 11 days, subject to regular admission. The connection with the blood plasma protein is quite low and is about 11%, the rest of the active substance is in a free state.
Biotransformation is carried out due to such enzymes as alcogol and aldehyde dehydrogenase, as well as aldehyde oxidase. The process of excretion of acyclovir is carried out with the process of urination and defecation, its duration is about 4 days. Almost the entire drug is excreted in the form of acyclovir, only a small residue is excreted by an unchanged substance.
Due to the fact that the production of acyclovir is underway, the active substance is able to penetrate into the viral particles and transform into its active forms, in particular triphosphate. This substance is built into the genetic apparatus of the virus and plays a role in the violation of its replication. Its high selective effect is justified by participation in the pathway of phosphorylation by an enzyme, which is produced by a viral particle.
Indications for Valtrex Use
You should take Valtrex when being diagnosed with one of the below-mentioned diseases:
- Shingles Herpes (Herpes zoster);
- Infections of the skin and mucous membranes caused by the herpes simplex virus, including primary and recurrent genital herpes;
- Labial herpes (labial fever);
- Treatment of recurrences of infections of the skin and mucous membranes caused by the herpes simplex virus, including genital herpes;
- Reducing the risk of transmission of the genital herpes virus to a healthy partner when using the drug as a prophylactic treatment in combination with safe sex;
- Prevention of cytomegalovirus infection after organ transplantation.
- Infections of the skin and mucous membranes caused by the herpes simplex virus, including primary and recurrent genital herpes;
- Labial herpes (labial fever);
- Treatment of recurrences of infections of the skin and mucous membranes caused by the herpes simplex virus, including genital herpes;
- Reducing the risk of transmission of the genital herpes virus to a healthy partner when using the drug as a prophylactic treatment in combination with safe sex;
- Prevention of cytomegalovirus infection after organ transplantation.
How to Take Valtrex?
This medication is taken orally. Consumption is allowed at any time, food intake does not affect suction, as well as distribution. Shingles is treated with valacyclovir in a dosage of 1000 mg three times a day for a week. In the case of a hermetic infection, the dose is 500 mg given twice daily for 10 days. At other pathologies, and also presence of any diseases the dosage is selected individually by the attending physician.
The drug should not be taken in cases of development of intolerance to any component in the composition, as well as in case of an allergic reaction to this drug in the history and in the following cases:
- Age under 12, as well as up to 18 years in order to treat herpes zoster or ophthalmic herpes zoster
- In severe HIV infection, which is accompanied by a decrease in the level of CD4 in a complex with lymphocytes below 100 per 1 μl.
- Pregnant/lactating women. In this case, the exact effect of the drug on the fetus and, subsequently, on the baby is not established, which is why it has not been prescribed yet.
- Elderly age.
- Reduction of the body’s defenses associated with severe somatic pathologies.
- Kidney disease, which is accompanied by a decrease in filtration and excretory function.
Which Adverse Reactions Can Valacyclovir Cause?
Side effects may develop from different body systems. Among them, the most important are:
- The defeat of the gastrointestinal tract, manifested by nausea, discomfort in the epigastric region, pain syndrome, vomiting, diarrhea, as well as anorexia.
- Changes from the central nervous system, which are expressed by headache, fatigue, dizziness, confusion, hallucinations.
- The appearance of allergic reactions. In this case, polymorphic eruptions, itching, burning, and in some cases the development of anaphylactic shock can be noted.
- Less often, photosensitivity and impaired renal function is manifested.
What will Happen if You Exceed the Dosage?
The use of the drug buy valtrex online in doses exceeding the allowable is hazardous to health. A person can have a life-threatening condition, which is associated with the deposition of insoluble salts in the renal tubule, leading to acute renal failure. If such a situation arises or signs of a violation or complete cessation of urinary excretion should be addressed to a medical institution for the provision of specialized care. The only effective procedure in this case will be systemic hemodialysis, as well as the subsequent connection to the apparatus of an artificial kidney.
Can Pregnant Women Treat Their Health Problems Using Valtrex?
There is no exact data indicating the effect of Valacyclovir on the course of pregnancy or fetus. This may be due to the fact that the experimental intake of pregnant women was not carried out. But with the introduction of Valacyclovir to rabbits, teratogenic action is not detected. It is allowed to take the drug if the health benefits for the pregnant women exceed the possible risks to both mother and the child. Data on side effects are not sufficient due to the low percentage of women using the drug during the first trimester.
Which Drugs Can Valtrex Interact with?
It should be noted that the use of valacyclovir with nephro toxic drugs is not recommended. This is associated with a high risk of side effects not only from the urinary system, as well as violations of the central and peripheral nervous system. Sharply increases the risk of acute renal failure. Preparations of cimetidine and Probenecid are not recommended to be consumed together or after Valaciclovir, as they are able to increase its concentration in the blood and lead to the development of a negative effect on the body, increasing the risk of side effects. Medicines containing copper, aluminum, magnesium and antacids do not adversely affect Valaciclovir.