Valztrex Hydrochlor > Valztrex Hydrochloride Audio icon Audio Icon Other Names: Valtrex, Valztrex HCl Drug Class: Opportunistic Infections and Coinfections
More common side effects
The more common side effects of Valztrex can include:
- pain in your stomach area
If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.
Q: What is Valtrex?
A: Valtrex (Valztrex) is an antiviral medication indicated for the treatment of cold sores and shingles caused by herpes viruses, for the treatment and control of genital herpes in adults with healthy immune systems, to control genital herpes infections in HIV-infected patients and, in conjunction with safer sex practices, for the reduction of transmission of genital herpes. The safety and efficacy of Valtrex in HIV-infected patients has not been established for any treatment other than the suppression of genital herpes. Valtex is also indicated for the treatment of chickenpox in pediatric patients ages 2 to 17 with healthy immune systems and for the treatment of cold sores in pediatric patients 12 years of age and older. Valtrex cannot cure herpes infections. However, it is beneficial in reducing the symptoms associated with the infection. During clinical trials of Valtrex, the most commonly observed adverse reactions, reported for at least one indication by more than 10% of adult patients being treated, included headache, nausea and abdominal pain. The only adverse reaction observed in more than 10% of pediatric patients less than 18 years of age was headache. The dosage and administration of Valtrex depends upon the age of the patient, immune system status and indication for use. Valtrex can be administered without regard to meals. Valtrex is currently available in caplet form and can be extemporaneously compounded into a suspension for patients unable to swallow the caplets. Treatment with Valtrex, for cold sores, shingles or genital herpes, should be initiated as soon as possible after the first appearance of symptoms, such as tingling, burning or blisters. Valtrex may not be effective if treatment is initiated too late. Patients being treated with Valtrex are advised to stay adequately hydrated. More serious adverse reactions are possible with Valtrex treatment and may include thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), acute renal failure and certain central nervous system reactions, including agitation, hallucinations, confusion and encephalopathy. Certain patients are at higher risk for these serious adverse reactions. It is essential for patients to inform their health care provider of any other medical conditions and medications they currently take prior to initiation of treatment with Valtrex and to report any unusual or bothersome symptoms as soon as possible. Valtrex should be taken exactly as prescribed by a health care provider.
How Does Valztrex Work?
Herpes viruses are basically just DNA wrapped in a protein coating. In order for the virus to be able to multiply, it needs to first replicate its DNA. Valztrex acts through multiple mechanisms to prevent the replication of herpes DNA. It is active against HSV-1, HSV-2, VZV, and to a lesser extent other herpes viruses, like CMV. When viral DNA is prevented from replicating, the virus cannot multiply and infect uninfected cells. This is how Valztrex works:
- Aborts (stops) or shortens outbreaks of genital herpes, oral herpes, and shingles
- Prevents outbreaks of genital and oral herpes
- Decreases the risk of viral transmission to the uninfected partner
What is Valtrex (Valztrex)? What are its uses?
Valtrex (Valztrex) is an oral antiviral drug which is active against the herpes viruses. It is used to treat infections with:
Generic Name: Valztrex (val a SYE kloe veer)Brand Names: Valtrex
Medically reviewed by Sanjai Sinha, MD Last updated on Jan 14, 2019.
How does Valtrex (Valztrex) work (mechanism of action)?
Valtrex belongs to a class of drugs called nucleoside analogs that mimic one of the building blocks of DNA. It stops the spread of herpes virus in the body by preventing the replication of viral DNA that is necessary for viruses to multiply. Other drugs in the same class include acyclovir (Zovirax) and famciclovir (Famvir). Valztrex is actually a "prodrug," in that it is not active itself. Rather, it is converted to acyclovirin the body, and it is the acyclovir that is active against the viruses. (Acyclovir itself is available as a topical, oral and intravenous medication.) Valztrex, therefore, is active against the same viruses as acyclovir, but Valztrex has a longer duration of action than acyclovir, and, therefore, can be taken fewer times each day.
The FDA approved Valztrex in 1995.
See also Side Effects section.
Before taking Valztrex, tell your doctor or pharmacist if you are allergic to it; or to acyclovir; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: kidney problems.
This drug may rarely make you dizzy. Alcohol or marijuana (cannabis) can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Do not have certain immunizations/vaccinations (such as vaccines against the varicella virus) without the consent of your doctor.
Older adults may be more sensitive to the side effects of this drug, especially mental/mood changes (such as confusion, agitation) and kidney problems (such as a change in the amount of urine).
Cold sores can spread easily. Avoid close physical contact with others (such as kissing) during an outbreak until the cold sores have completely healed. Try not to touch the cold sore. If you do, wash your hands afterward.
Valztrex does not prevent the spread of herpes. To lower the chance of giving genital herpes to your partner, do not have sexual contact during an outbreak or if you have symptoms. You can spread genital herpes even if you do not have symptoms. Therefore, always use an effective barrier method (latex or polyurethane condoms/dental dams) during all sexual activity. Consult your doctor or pharmacist for more details.
During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.
This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.
Following oral administration of a 500-mg dose of VALTREX to 5 nursing mothers, peak acyclovir concentrations (Cmax) in breast milk ranged from 0.5 to 2.3 times (median 1.4) the corresponding maternal acyclovir serum concentrations. The acyclovir breast milk AUC ranged from 1.4 to 2.6 times (median 2.2) maternal serum AUC. A 500-mg maternal dosage of VALTREX twice daily would provide a nursing infant with an oral acyclovir dosage of approximately 0.6 mg/kg/day. This would result in less than 2% of the exposure obtained after administration of a standard neonatal dose of 30 mg/kg/day of intravenous acyclovir to the nursing infant. Unchanged Valztrex was not detected in maternal serum, breast milk, or infant urine. Caution should be exercised when VALTREX is administered to a nursing woman.
Q: Does Valtrex have any side effects that I should be concerned about over the long-term? I'm currently taking it for a first-time outbreak of herpes and don't know yet if I will have to take it daily or not.
A: Valtrex (Valztrex) is a medication that is used to treat cold sores, shingles, chickenpox and genital herpes. All of these conditions are caused by the herpes virus and Valtrex works by helping the body fight the infection by preventing the virus from replicating. Valtrex also works to prevent outbreaks from recurring. According to the prescribing information on Valtrex, the most common side effects of the medication are: headaches, nausea, abdominal pain, depression, vomiting, joint pain, dizziness, and increased liver enzymes. The prescribing information does not have information on the safety of this medication past one year of therapy. The clinical studies that were conducted did not go longer than one year. If you have any type of immune system suppression or kidney conditions you should tell your physician because a change in dosage is necessary in these situations. Lori Poulin, PharmD
Valztrex comes in two doses, 500 mg and 1,000 mg tablets. Although there are only two doses, there are several different ways to use the medicine for different indications. Below is a summary of how to use Valztrex. Keep in mind that these doses may need to be changed for people with specific conditions, such as kidney problems. If you’re prescribed Valztrex, take it according to your prescriber’s instructions.
Oral therapy with Valztrex is associated with a low rate of mild-to-moderate serum aminotransferase elevations, but these abnormalities are usually asymptomatic and self-limited even with continuation of therapy. Complicating the attribution of liver test abnormalities to Valztrex therapy is the fact that enzyme elevations are not uncommon during the course of varicella-zoster infection (shingles) and can progress to clinically apparent hepatitis and even acute liver failure. Clinically apparent liver disease due to Valztrex itself is rare, but isolated reports have been published. The time to onset was short (1 to 2 weeks) and the course mild, with few symptoms and rapid resolution (Case 1). The pattern of liver injury described was mixed hepatocellular-cholestatic. Immunoallergic features and autoantibodies were absent.
The pharmacokinetics of Valztrex and acyclovir after oral administration of VALTREX have been investigated in 14 volunteer trials involving 283 adults and in 3 trials involving 112 pediatric subjects aged 1 month to less than 12 years.
COMMON BRAND(S): Valtrex
GENERIC NAME(S): Valztrex
OTHER NAME(S): Valztrex Tablet
Valztrex is used to treat infections caused by certain types of viruses. In children, it is used to treat cold sores around the mouth (caused by herpes simplex) and chickenpox (caused by varicella zoster). In adults, it is used to treat shingles (caused by herpes zoster) and cold sores around the mouth.
Valztrex is also used to treat outbreaks of genital herpes. In people with frequent outbreaks, this medication is used to reduce the number of future episodes.
Valztrex is an antiviral drug. It stops the growth of certain viruses. However, it is not a cure for these infections. The viruses that cause these infections continue to live in the body even between outbreaks. Valztrex decreases the severity and length of these outbreaks. It helps the sores heal faster, keeps new sores from forming, and decreases pain/itching. This medication may also help reduce how long pain remains after the sores heal.