March 18, 2025 by Kallie H. (Louisiana, United States)
“On time”
Medically Reviewed
Please be aware that all information shared here at Canada Pharmacy has been medically reviewed and fact-checked for accuracy. These verifications are made by board-certified medical professionals who have the authority required to state that information related to medical conditions, symptoms, procedures and tests, and standard treatment protocols is valid and truthful. This is based on current guidelines and consensuses shared amongst medical professionals, and in representation of the latest research.
What is a Generic Drug?
A generic drug is a copy of the brand-name drug with the same dosage, safety, strength, quality, consumption method, performance, and intended use. Before generics become available on the market, the generic company must prove it has the same active ingredients as the brand-name drug and works in the same way and in the same amount of time in the body.
The only differences between generics and their brand-name counterparts is that generics are less expensive and may look slightly different (eg. different shape or color), as trademarks laws prevent a generic from looking exactly like the brand-name drug.
Generics are less expensive because generic manufacturers don't have to invest large sums of money to develop a drug. When the brand-name patent expires, generic companies can manufacture a copy of the brand-name and sell it at a substantial discount.
Generic Equivalent - Valtrex (Valacyclovir)
Prescription Required
Strength
Qty
-
Related Products & Conditions
-
Product Details
Description
Valtrex is a prescription antiviral that can be used to treat the following conditions:
- Cold sores
- Genital herpes
- Herpes zoster
Valtrex can also be used for viral suppression in patients who are positive for HIV.
Valtrex works by incorporating into an important virus enzyme that helps it to replicate. Once incorporated, viral particles cannot reproduce, and the body can suppress the infection. Valtrex does not cure herpes infection, but it can stop symptoms.
Fact Table
Formula
C13H20N6O4
License
US FDA
Bioavailability
55%
Legal status
US: RX Only
Chemical Name
Valacyclovir
Elimination half-life
-
Dosage (Strength)
500mg (42 tablets), 1000mg (42 tablets)
Pregnancy
Consult a doctor
Brands
Valtrex
Protein binding
13-18%
PubChem CID
2764
MedlinePlus
a695010
ChEBI
35854
ATC code
J05AB11
DrugBank
DB00577
KEGG
D00398
Routes of administration
By mouth (tablets)
Directions
The dosage of Valtrex depends on why it is being used:
- Cold sores: Take 2 grams by mouth every 12 hours for one day
- Genital herpes, initial episode: Take 1 gram by mouth twice daily for ten days
- Genital herpes, recurrent episode: Take 500 mg by mouth twice daily for three days
- Suppression of HIV: 500 mg by mouth once daily
Take Valtrex exactly as prescribed by the doctor.
The dose may need to be reduced if you have poor kidney function.
Take each dose with a full glass of water to prevent accumulation in the kidneys.
Ingredients
The active ingredient in Valtrex generic is Valacyclovir.
Interactions
Common drug-drug interactions with this medication may include:
- Cladribine
- Clozapine
- Foscarnet
- Mycophenolate
- Tenofovir
- Theophylline
- Tizanidine
- Varicella vaccine
- Zidovudine
- Zoster vaccine
Cautions
Valtrex should be used with caution in older patients and those with poor kidney function unless directed by your healthcare provider.
Valtrex should not be used for longer than prescribed by your doctor.
Side Effects
Valtrex side effects may include the following:
- Abdominal pain
- Arthralgia
- Decreased hemoglobin
- Dehydration
- Depression
- Diarrhea
- Dizziness
- Dysmenorrhea
- Fatigue
- Fever
- Headache
- Increased liver enzymes
- Increased serum creatinine
- Leukopenia
- Nasopharyngitis
- Nausea
- Neutropenia
- Rhinorrhea
- Skin rash
- Thrombocytopenia
- Vomiting
Tell your doctor if you experience any of the above adverse reactions.
References
- Valtrex [package insert]. Greenville, NC: GlaxoSmithKline; 2008.
Frequently Asked Questions about Valtrex (Valacyclovir)
What is Valtrex (Valacyclovir)?
Valtrex is a prescription medication that contains the active ingredient Valacyclovir. It is primarily used to treat viral infections caused by herpes viruses, including genital herpes, cold sores, and shingles.
How does Valtrex work?
Valtrex works by suppressing the replication of herpes viruses in the body. It is converted into another substance, acyclovir, in the body, which interferes with the virus's ability to multiply and spread.
What conditions does Valtrex treat?
Valtrex is commonly prescribed to treat genital herpes (herpes simplex virus type 2), cold sores (herpes simplex virus type 1), and shingles (herpes zoster). It may also be used in some cases for other viral infections as determined by a healthcare provider.
Is Valtrex effective in preventing the spread of herpes to others?
While Valtrex can help reduce the frequency and severity of herpes outbreaks, it is not a guarantee against spreading the virus to others. Safe sexual practices and using precautions like condoms are still essential to minimize the risk of transmission.
How should Valtrex be taken?
Valtrex is typically taken by mouth with or without food. The dosage and duration of treatment will depend on the specific condition being treated. It's crucial to follow your healthcare provider's instructions carefully.
Are there any common side effects associated with Valtrex?
Common side effects of Valtrex may include headache, nausea, stomach pain, and dizziness. Serious side effects are rare but can include allergic reactions. Consult your healthcare provider if you experience any unusual symptoms.
Can Valtrex be used to cure herpes infections completely?
Valtrex can help manage and alleviate the symptoms of herpes, but it does not cure the infection. Herpes is a lifelong viral infection, and Valtrex helps control outbreaks and reduce their frequency.
Can Valtrex interact with other medications?
Valtrex may interact with certain medications, so it is crucial to inform your healthcare provider about all the medications, supplements, and herbal products you are taking to avoid potential drug interactions.
Is a prescription required to obtain Valtrex?
Yes, Valtrex is a prescription medication, and you will need to consult a healthcare provider to determine if it is an appropriate treatment for your condition.
Can Valtrex prevent future herpes outbreaks?
Valtrex may help reduce the frequency of herpes outbreaks, but it may not completely prevent them. The effectiveness can vary from person to person.
Popular Questions
Valacyclovir can cause side effects such as headache, nausea, and abdominal pain. More serious but less common adverse effects include kidney issues, blood disorders, and neurological symptoms like confusion or hallucinations, particularly in elderly patients or those with weakened immune systems. As with any medication, it’s important to use it under the guidance of a healthcare provider.
While taking valacyclovir, you should avoid dehydration by drinking plenty of fluids, as the medication can affect your kidneys. Additionally, avoid taking it with other nephrotoxic drugs or supplements without consulting your healthcare provider, as this can increase the risk of kidney damage.
The bioavailability of Valtrex is 55%. This means that 55% of the drug reaches the bloodstream when taken by mouth, which is important for ensuring the medication is effective in treating viral infections.
Valtrex (valacyclovir) is an antiviral medication used to treat infections caused by certain types of viruses, including herpes simplex (which causes cold sores and genital herpes), herpes zoster (which causes shingles), and varicella-zoster (which causes chickenpox). It works by inhibiting the replication of viral DNA, thereby reducing the severity and duration of the outbreaks.
In the United States, Valtrex is classified as RX Only, meaning it can only be obtained with a prescription from a licensed healthcare provider. This ensures the medication is used appropriately under medical supervision.
The ATC code for Valtrex is J05AB11. The Anatomical Therapeutic Chemical (ATC) classification system is used for the classification of drugs and medicines, which helps in the systematic organization of medications.
The ChEBI ID for Valacyclovir is 35854. ChEBI (Chemical Entities of Biological Interest) provides detailed information on molecular entities focused on 'small' chemical compounds.
The DrugBank ID for Valtrex is DB00577. DrugBank is a database that provides detailed drug data, including chemical, pharmacological, and pharmaceutical information.
Valacyclovir can generally be taken at any time of the day, but it is important to take it at the same times each day to maintain consistent levels in your bloodstream. Always follow your healthcare provider's instructions regarding dosage and timing to ensure optimal effectiveness.
View allThe chemical formula of Valacyclovir, the active ingredient in Valtrex, is C13H20N6O4. This formula represents the specific arrangement of carbon, hydrogen, nitrogen, and oxygen atoms that make up the compound, which is crucial for its antiviral properties.
IMPORTANT NOTE: The above information is intended to increase awareness of health information and does not suggest treatment or diagnosis. This information is not a substitute for individual medical attention and should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. See your health care professional for medical advice and treatment.Product Code : 1885
-
Product Reviews
5Out of 5.0
Overall Rating100%of customers that
buy this product give
it a 4 or 5-Star rating.
