How long does it take for Valtrex to work. What is the recommended dosage for different conditions. When should you start taking Valtrex for optimal results. How effective is Valacyclovir for treating herpes outbreaks.

Understanding Valacyclovir: A Powerful Antiviral Medication

Valacyclovir, commonly known by its brand name Valtrex, is a widely prescribed antiviral medication used to treat various herpes virus infections. This potent drug helps manage symptoms associated with cold sores, shingles, genital herpes, and chickenpox. While it doesn’t cure these conditions, Valacyclovir effectively controls outbreaks and reduces their severity.

How does Valacyclovir work in the body? Once ingested, it converts into acyclovir, the active antiviral compound. In individuals with normal kidney function, acyclovir has a half-life of 2.5 to 3.3 hours. This means the drug remains active in your system for this duration, continuously fighting the virus.

Timing Is Crucial: When to Start Valacyclovir Treatment

The effectiveness of Valacyclovir largely depends on how quickly you begin treatment after noticing symptoms. For optimal results, it’s crucial to start taking the medication as soon as possible.

• First-time herpes outbreaks: Begin treatment within 48 hours of symptom onset
• Recurrent herpes outbreaks: Start as soon as you notice signs of an outbreak
• Shingles: Commence treatment within 72 hours of symptom appearance
• Cold sores: Begin taking Valacyclovir at the first tingle or sign of a developing cold sore

Why is early treatment so important? Starting Valacyclovir promptly can significantly reduce the severity and duration of symptoms, providing faster relief and minimizing the risk of complications.

Dosage Guidelines: How Much Valacyclovir Should You Take?

The appropriate dosage of Valacyclovir varies depending on the specific condition being treated. Always follow your healthcare provider’s instructions, as they may adjust the dosage based on your individual needs.

Typical Valacyclovir Dosages:

• First-time herpes outbreak: 1,000 mg twice daily for 10 days
• Recurrent herpes outbreaks: 500 mg twice daily for 3 days
• Shingles: 1,000 mg three times daily for 7 days
• Cold sores: Two doses of 2,000 mg, taken 12 hours apart

Is it possible to adjust these dosages? In some cases, your doctor may prescribe a different dosage or duration of treatment based on factors such as the severity of your symptoms, your overall health, and your response to the medication.

Valacyclovir for First-Time Herpes Outbreaks: What to Expect

Experiencing your first herpes outbreak can be distressing, but Valacyclovir can help manage symptoms effectively. When taken within 48 hours of symptom onset, it can significantly reduce the severity and duration of the outbreak.

How quickly will you notice improvements? While Valacyclovir begins working as soon as it’s in your system, it may take several days to see noticeable improvements. In some cases, it can take up to 10 days or longer for herpes blisters to heal completely, even with treatment.

Why is it essential to complete the full course of medication? Even if your symptoms improve before the end of the prescribed treatment period, it’s crucial to take all the medication as directed. This helps ensure the virus is fully suppressed and reduces the risk of developing drug-resistant strains.

Managing Recurrent Herpes Outbreaks with Valacyclovir

For individuals experiencing recurrent herpes outbreaks, Valacyclovir can provide fast and effective relief. The typical dosage for recurrent outbreaks is lower than for initial infections, but the medication works just as efficiently to control symptoms.

How often do herpes outbreaks typically occur? On average, people with HSV-1 (oral herpes) experience about one outbreak per year, while those with HSV-2 (genital herpes) may have four to five outbreaks annually. However, this can vary greatly between individuals.

Can Valacyclovir reduce the frequency of outbreaks? Yes, when taken as prescribed, Valacyclovir can help suppress the herpes virus, potentially reducing the number of outbreaks you experience over time. Some people may benefit from daily suppressive therapy to further minimize outbreaks and reduce the risk of transmission to partners.

Valacyclovir for Shingles: Timing and Effectiveness

Shingles, caused by the reactivation of the varicella-zoster virus, can be an extremely painful condition. Valacyclovir is a key treatment option, but its effectiveness is highly dependent on timely administration.

Why is it critical to start treatment within 72 hours? Beginning Valacyclovir treatment within this window can significantly reduce the severity and duration of the shingles outbreak. It may also help prevent postherpetic neuralgia, a painful complication that can persist long after the rash has healed.

What if treatment is delayed beyond 72 hours? While it’s best to start treatment as soon as possible, some studies suggest that Valacyclovir may still offer benefits even if started after the 72-hour window, particularly in reducing pain and accelerating healing. However, the effectiveness may be reduced compared to early treatment.

Cold Sore Treatment: Maximizing Valacyclovir’s Efficacy

Cold sores, caused by HSV-1, can be both painful and embarrassing. Valacyclovir offers a powerful treatment option, but timing is crucial for optimal results.

How quickly should you start treatment for cold sores? Ideally, you should begin taking Valacyclovir at the first sign of a cold sore – often a tingling or burning sensation before the blister appears. This early intervention can sometimes prevent the cold sore from fully developing.

What if you’ve already developed a blister? Even if a cold sore has already formed, starting Valacyclovir can still help. It may reduce the duration of the outbreak and alleviate symptoms more quickly than if left untreated.

Is it possible to prevent cold sores with Valacyclovir? For individuals who experience frequent cold sores, daily suppressive therapy with a lower dose of Valacyclovir may be recommended to reduce the frequency of outbreaks.

Valacyclovir Side Effects and Precautions

While Valacyclovir is generally well-tolerated, like all medications, it can cause side effects in some individuals. It’s important to be aware of potential side effects and take necessary precautions.

Common Side Effects:

• Headache
• Nausea
• Abdominal pain
• Dizziness
• Fatigue

Are there any serious side effects to watch for? While rare, serious side effects can occur. These may include:

• Kidney problems
• Unusual bruising or bleeding
• Severe dizziness or fainting
• Signs of a severe allergic reaction

Who should exercise caution when taking Valacyclovir? Individuals with kidney problems, the elderly, and those taking certain other medications may need dose adjustments or closer monitoring while on Valacyclovir. Always inform your healthcare provider about all medications and supplements you’re taking.

Valacyclovir and Pregnancy: Safety Considerations

For pregnant women with herpes infections, managing outbreaks while ensuring the safety of the developing fetus is crucial. Valacyclovir can play a role in this delicate balance.

Is Valacyclovir safe during pregnancy? Current research suggests that Valacyclovir is generally safe for use during pregnancy. It’s classified as Category B by the FDA, meaning animal studies have not shown a risk to the fetus, but there aren’t enough well-controlled studies in pregnant women.

Why might Valacyclovir be prescribed during pregnancy? In some cases, especially when there’s a risk of transmission to the baby during delivery, a healthcare provider may recommend Valacyclovir to suppress outbreaks. This can help reduce the need for a cesarean section.

What about breastfeeding? Valacyclovir does pass into breast milk, but it’s generally considered safe for breastfeeding mothers. However, always consult with your healthcare provider to weigh the potential risks and benefits in your specific situation.

Long-Term Use of Valacyclovir: Benefits and Considerations

For some individuals with recurrent herpes outbreaks, long-term or suppressive therapy with Valacyclovir may be recommended. This approach can offer several benefits but also requires careful consideration.

What are the advantages of suppressive therapy? Daily Valacyclovir can significantly reduce the frequency of outbreaks, potentially improving quality of life. It may also lower the risk of transmitting the virus to sexual partners.

Are there any risks associated with long-term use? While Valacyclovir is generally safe for extended use, long-term therapy requires regular monitoring. Your healthcare provider may recommend periodic blood tests to check kidney function and adjust dosage if necessary.

Can you develop resistance to Valacyclovir over time? While possible, resistance to Valacyclovir is relatively rare in immunocompetent individuals. However, it’s more common in people with weakened immune systems, such as those with HIV/AIDS or organ transplant recipients.

Valacyclovir vs. Other Antiviral Medications: A Comparison

While Valacyclovir is a widely used antiviral medication, it’s not the only option available for treating herpes infections. Understanding how it compares to other antivirals can help inform treatment decisions.

Valacyclovir vs. Acyclovir:

• Valacyclovir is a prodrug of acyclovir, meaning it’s converted to acyclovir in the body
• Valacyclovir has better bioavailability, allowing for less frequent dosing
• Both are equally effective, but Valacyclovir’s dosing schedule may be more convenient for some patients

Valacyclovir vs. Famciclovir:

• Both are effective against herpes viruses
• Famciclovir may have a slightly longer half-life in the body
• The choice between these medications often depends on individual factors and physician preference

How do these medications differ in terms of side effects? While all these antivirals have similar side effect profiles, individual responses can vary. Some people may tolerate one medication better than another.

Maximizing Valacyclovir’s Effectiveness: Tips and Strategies

To get the most benefit from your Valacyclovir treatment, consider these strategies:

1. Start treatment early: Begin taking Valacyclovir as soon as you notice symptoms for best results
2. Stay hydrated: Drinking plenty of water can help prevent potential side effects and support your body’s healing process
3. Take as directed: Follow your healthcare provider’s instructions carefully, including dosage and duration of treatment
4. Be consistent: If on suppressive therapy, take your medication at the same time each day to maintain steady levels in your system
5. Monitor triggers: Keep track of factors that may trigger outbreaks, such as stress or certain foods, and try to avoid them
6. Practice good hygiene: Wash your hands frequently, especially during outbreaks, to prevent spreading the virus
7. Communicate with your healthcare provider: Report any unusual symptoms or concerns promptly

Can lifestyle changes enhance the effectiveness of Valacyclovir? Absolutely. Maintaining a healthy lifestyle, including a balanced diet, regular exercise, and stress management, can support your immune system and potentially reduce the frequency of outbreaks.

The Future of Herpes Treatment: Beyond Valacyclovir

While Valacyclovir remains a cornerstone of herpes treatment, ongoing research is exploring new avenues for managing and potentially curing herpes infections.

What new treatments are on the horizon? Several promising approaches are being investigated, including:

• Gene editing techniques to eliminate the virus from infected cells
• Therapeutic vaccines to boost the immune system’s response to the virus
• Novel antiviral compounds targeting different stages of the viral life cycle

Will we see a cure for herpes in the near future? While a complete cure remains elusive, significant progress is being made. However, it’s important to remember that developing new treatments and bringing them to market is a long and complex process.

How can current patients benefit from ongoing research? Staying informed about new developments can help you have more productive conversations with your healthcare provider about treatment options. Additionally, you may have opportunities to participate in clinical trials for new therapies.

Conclusion

Valacyclovir is a powerful tool in managing herpes infections, offering relief from symptoms and reducing the risk of transmission. Its effectiveness is maximized when treatment is started promptly and taken as directed. While it’s not a cure, Valacyclovir can significantly improve quality of life for those living with herpes infections.

Remember, every individual’s experience with herpes and its treatment is unique. Always consult with your healthcare provider to develop a treatment plan tailored to your specific needs and circumstances. With proper management and the support of medications like Valacyclovir, it’s possible to live a full and healthy life while managing herpes infections effectively.

How Long Does Valacyclovir (Valtrex) Take to Work?

Medically reviewed by Mary Lucas, RN

Written by Our Editorial Team

Last updated 4/26/2020

Valacyclovir (commonly sold as Valtrex) is one of the most widely used and effective drugs on the market for treating and controlling cold sores, shingles and genital herpes.

While valacyclovir isn’t a cure for herpes, it can help to treat the physical symptoms of HSV-1 and HSV-2. Valacyclovir is also commonly prescribed for chickenpox, which is caused by the varicella zoster virus (VZV).

The amount of time required for valacyclovir to start working can vary based on a number of factors, ranging from the type of infection you have to your valacyclovir dosage and the total amount of time that passes after you notice symptoms but before you start treatment.

In this guide, we’ll look at some of the most common situations in which you’d use valacyclovir for treatment, as well as the approximate amount of time it should take for valacyclovir to offer relief.

Valacyclovir for First Herpes Outbreaks

For first-time herpes outbreaks, valacyclovir is most effective when it’s used within 48 hours of symptoms appearing. Once valacyclovir has converted into acyclovir, it has a half-life of 2.5 to 3.3 hours in people with normal renal function. Meaning Valacyclovir stay in your system from 2.5 to 3.3 hours for normal people.

The standard dosage of valacyclovir for first-time herpes outbreaks is 1,000 mg two times per day over a period of 10 days. Valacyclovir usually starts treating herpes symptoms as soon as it’s in your system, but can take several days to produce a noticeable improvement.

It can take up to 10 days (or, in some cases, even longer) for herpes blisters to heal even with valacyclovir treatment. This makes it important to start treatment as soon as you notice herpes symptoms.

In some cases, your doctor might prescribe valacyclovir for a longer period than 10 days or at a different dosage. In this case, follow your doctor’s instructions and make sure you complete the full course of the medication, even if the herpes blisters heal before the end of the period.

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Some keep their breakouts at bay with a once daily pill. Connect with a healthcare provider and discover your treatment options.

Valacyclovir for Recurrent Herpes Outbreaks

Herpes can remain dormant in the body for weeks, months or years in between outbreaks. On average, people with HSV-1 experience about one outbreak per year, while people with HSV-2 will usually experience four to five outbreaks per year.

When these outbreaks occur, valacyclovir can provide fast and effective relief, helping to control herpes outbreak symptoms.

The typical valacyclovir dosage for recurrent herpes outbreaks is 500 mg two times per day over a period of three days. Like with first-time herpes outbreaks, valacyclovir is most effective when it’s taken as soon as you notice a herpes outbreak developing.

When taken as soon as you notice a herpes outbreak, valacyclovir can provide relief in as little as two to three days, minimizing symptoms and reducing the risk of you passing genital herpes to sexual partners.

>>MORE: HSV 1 vs. HSV 2 – What’s the difference?

Valacyclovir for Shingles

Valacyclovir is usually prescribed for seven days for shingles, with a typical dosage of 1,000 mg three times per day.

Just like with HSV-1 and HSV-2, it’s important to start treatment as soon as you notice shingles symptoms. Most experts recommend starting valacyclovir within 72 hours of noticing symptoms for the best results.

Valacyclovir (Valtrex) for Cold Sores

For cold sores, valacyclovir or valtrex is usually taken in two large doses of 2,000 mg, split 12 hours apart from each other. Like with other outbreaks of HSV, valacyclovir will speed up the speed at which cold sores heal, but it can still take seven to 10 days for them to fully disappear.

Worried About Herpes? Act Quickly for Faster Relief

From cold sores to genital herpes, acting quickly helps you treat and control a herpes outbreak in the shortest amount of time. For this reason, most doctors recommend using valacyclovir in the first 24-72 hours after noticing a cold sore or other herpes blister developing.

If you’ve noticed a cold sore or any of the other symptoms of a herpes outbreak, it’s best to talk to your doctor about treatment and relief options as soon as possible.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

What You Need To Know

Content

• Overview
• What is Valtrex?
• How does Valtrex help with cold sores?
• How do you take Valtrex?
• How quickly does Valtrex work?
• When should you start taking Valtrex for cold sores?
• Do cold sores stop being contagious after taking Valtrex?
• Does Valtrex have any side effects?
• Can you take Valtrex together with other medications?
• How should you take Valtrex during a cold-sore outbreak?
• What happens if you miss a Valtrex dose?
• Can anyone take Valtrex?
• Is Valtrex safe to take while pregnant or breastfeeding?
• The lowdown

Cold sores are caused by certain variants of the herpes simplex virus (HSV). HSV is classified into two categories: HSV Type 1 (HSV-1) and HSV Type 2 (HSV-2). 

HSV-1 (oral herpes) is typically transmitted via oral-to-oral contacts, such as kissing and is primarily responsible for the infection in or around the mouth (cold sores).

HSV-2 is a sexually transmitted infection that is commonly known as genital herpes. Infection with HSV is quite common, with estimates showing that 50% to 80%¹ of the American adult population have HSV-1. According to the CDC, 11.9% of people aged 15–49² in the United States have an HSV-2 infection. 

While cold sores are mainly attributed to HSV-1, either strain of the HSV virus can spread to the mouth or genitals through close contact. Once in the body, the virus can remain dormant for long periods in between outbreaks. People with HSV-1 typically experience about one episode yearly, while HSV-2 flare-ups are more common.

Your doctor may prescribe Valtrex to control cold sores and other herpes outbreak symptoms when these outbreaks occur.   

Have you considered clinical trials for Cold sores?

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Valtrex (generic name valacyclovir) is a prescription antiviral drug used to treat diseases caused by certain types of viruses, such as HSV. It’s one of the most widely used and effective drugs for treating and managing cold sores.

Valtrex can shorten the duration of cold sores, but it does not cure oral herpes. More importantly, Valtrex will not prevent you from spreading the infection to other people. 

Valtrex is also used to treat genital herpes (genital lesions) and shingles (herpes zoster) in adults. Doctors may prescribe Valtrex for chickenpox in children at least two years old. 

Antiviral drugs don’t kill viruses; they inhibit their ability to grow and multiply. Valtrex slows the growth and spread of HSV to help the immune system fight the infection. That way, the drug may help shorten spells of cold sores and blisters during oral herpes outbreaks.

In other words, Valtrex and similar antiviral medications treat cold sores by limiting how much the HSV-1 virus grows and spreads. Preventing the virus from growing and spreading reduces the intensity of cold sores and other symptoms associated with HSV-1 infection or outbreak. 

Cold sore medication can be administered orally or in antiviral creams. Creams must be applied several times daily and are less effective than oral medications. Oral tablets are available in 500-milligram and 1-gram strengths 

For an adult looking to treat cold sores, a healthcare professional will typically prescribe two grams twice daily, taken 12 hours apart, for ten days. For the best outcomes, oral medications such as Valtrex should be taken at the initial sign of a cold sore. 

Note that Valtrex is not just used to treat cold sores. A doctor may also prescribe Valtrex or another antiviral medication to prevent cold sores. Taking Valtrex daily reduces the chances of cold sores recurring by about 30%. 

The time it takes your symptoms to go away after Valtrex is administered will depend on a few factors. These include your metabolism, the severity of your symptoms, and age. Usually, cold sores can go away on their own in seven to 10 days. 

According to a Harvard Health³ publication, antiviral medications such as Valtrex can slightly shorten the time it takes for cold sores to heal completely by a day or two. 

In another study,⁴ participants who took Valtrex within two hours of noticing their first cold sore symptoms had shorter cold sore flare-ups by about one day compared to those who didn’t take the drug.

Ultimately, the speed of recovery depends on how soon you recognize the symptoms and get started on the medication. Therefore, you must start treatment as soon as you notice cold sore symptoms developing. Follow your doctor’s instructions and ensure you complete the entire course of the medication, even if your cold sores heal before the end of the period.

Taking Valtrex after a cold sore appears provides fast and effective relief from the blisters and other symptoms of HSV-1 infection. You should take the medication as soon as you notice cold sores developing. 

Being familiar with the other symptoms of oral herpes can help you sense a looming outbreak and start seeking relief options. 

So, what are the symptoms of an oral herpes outbreak? Well, in most cases, recurring HSV-1 infections are asymptomatic, but if present, symptoms can include: 

• Redness, tingling, burning, itchiness, and swelling in the lips or the area where the cold sores will erupt 

• Painful, fluid-filled blisters start to erupt on the edges of the lip or inside the mouth

• Blisters turn to sores as the fluid begins to leak

• The sores begin to crust over and heal after a few days

These are the most common signs and symptoms of a recurring HSV-1 infection. Start medication or seek other relief options when you notice the initial redness, itching, pain or heat, and swelling in the lips or other areas around your mouth.  

Note that the initial HSV-1 infection is usually the worst. You may experience severe, flu-like symptoms, including headache and swollen lymph nodes. The signs of an initial or recurring HSV-1 infection may be similar to other conditions, so always consult a doctor for an accurate diagnosis.

Cold sores can be quickly passed from person to person by direct skin contact with the affected area. The infection can spread from when you first feel tingling or burning until after it has scabbed over, which usually takes about 15 days. However, cold sores are most infectious when there are oozing blisters.

Do cold sores stop being contagious after taking Valtrex? No, cold sores don’t stop being contagious until after they are completely healed. Valtrex prevents the virus from growing and spreading, speeds up the healing process, and significantly reduces the period you remain contagious. 

Valtrex is available through prescription only and may have specific side effects in some people. According to the National Library of Medicine,⁵ the most common side effects in people using Valtrex for cold sores are: 

• Dizziness 

• Abdominal pain

• Nausea 

• Headache

Valtrex can also trigger allergic reactions in some people. Call your doctor immediately if you exhibit signs of an allergic reaction to Valtrex. These include swelling of your tongue, throat, lips, or face; difficulty breathing; or hives. 

Although it’s rare, Valtrex can also cause life-threatening side effects. Stop taking Valtrex and get emergency medical help if you experience hallucinations, confusion, speech problems, seizure, kidney failure, or other serious side effects. 

It’s generally safe to take Valtrex simultaneously with other medications. There are no known significant drug interactions between Valtrex and other medications. However, inform your physician about all other medicines you use. 

Better still, bring a complete list of all the prescription drugs and supplements you’re taking to your doctor. Your doctor may need to adjust your dosage or perform specific tests when taking other medicines with Valtrex.

If you are experiencing a herpes flare-up, start taking Valtrex as soon as you notice the initial symptoms—redness, tingling, burning, itchiness, and swelling in and around the mouth. That’s when the drug is most effective. 

Take Valtrex as prescribed by your healthcare provider. Do not take the drug in higher or lower dosages or for more extended periods than your doctor recommends. Stick to the prescription even if your symptoms improve before the prescribed length ends. You risk making the virus resistant to antiviral medications by skipping doses.  

Additionally, you should take Valtrex with a full glass of water (eight ounces). The water will help your kidneys process the drug more efficiently. Swallowing medications such as Valtrex without enough water may prevent them from acting properly. In some cases, it may even lead to adverse side effects.

Life happens, and you may find that you’ve missed your Valtrex dose through no fault of your own. If you happen to miss a dose for any reason, don’t panic. Take the missed dose as soon as you are able. 

You can miss the skipped dose and resume your regular schedule if it’s almost time for your next scheduled dose. This is the only time you should skip a dose. You should never take an extra Valtrex dose to make up for the one you didn’t take. 

Even though Valtrex is generally safe and relatively effective at treating cold sores and other HSV symptoms, it shouldn’t be taken by everyone. You should discuss with your healthcare provider before taking Valtrex if you: 

Are 65 years or older

People 65 years or older are more likely to experience adverse side effects after taking Valtrex. However, this doesn’t mean that older adults can’t take this medication if they are experiencing a herpes flare-up. Your healthcare provider can prescribe a lower dose.

Have underlying health conditions

Some underlying health conditions can make it unsafe for some people to take Valtrex. For instance, people with kidney problems or kidney disease could experience adverse symptoms from taking Valtrex. You should also talk to your doctor before taking Valtrex if you have HIV. 

Valtrex is not recommended for treating cold sores in children 11 years and younger. However, it can treat other viral infections, such as chickenpox, in children two years and older.

You may wonder if you can take Valtrex while pregnant or when breastfeeding. As an expectant mother, talk to your healthcare provider if you’re thinking about taking Valtrex. They will tell you how it might affect your pregnancy. Your doctor may prescribe Valtrex if the benefit is felt to outweigh the risk of potential side effects.

Generally, Valtrex is safe to take during breastfeeding. Again, you should always consult a healthcare professional about taking it while nursing.

HSV-1 infections can be asymptomatic or have mild symptoms that are unnoticeable. When symptoms occur, oral herpes is characterized by open sores or painful blisters in and around the mouth (cold sores). HSV-1 can remain dormant for long periods in between periodic flare-ups.

Valtrex is an antiviral medication that treats cold sores and other HSV symptoms. The drug is most effective when you take it as soon as you notice cold sores developing. When taken correctly, the drug can provide relief and reduce the risk of you spreading the infection to other people.

Valtrex does not heal the cold sores or the underlying HSV infection. Instead, it may reduce the duration of blisters and cold sore flare-ups. Valtrex is not an over-the-counter medication, so you’ll need a prescription to treat your cold sores or oral herpes flare-up.  

Although Valtrex is generally safe and effective at treating cold sores, it shouldn’t be taken by just anyone. If you notice cold sores or any other symptoms of an HSV-1 outbreak, talk to your doctor about treatment and relief options as soon as possible.

Memorial Sloan Kettering Cancer Center

Adult Medication

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Provided by Lexicomp ^® , this document contains all the information you need to know about this medicine, including indications, directions for use, side effects, and when your healthcare provider should be contacted.

Trade names: USA

Valtrex

Brand names: Canada

AG-Valacyclovir; APO-Valacyclovir; Auro-Valacyclovir; BIO-Valacyclovir [DSC]; DOM-Valacyclovir [DSC]; JAMP Valacyclovir; JAMP-Valacyclovir; Mar-Valacyclovir [DSC]; MYLAN-Valacyclovir; PMS-Valacyclovir; Priva-Valacyclovir [DSC]; PRO-Valacyclovir; RIVA-Valacyclovir; SANDOZ Valacyclovir; TEVA-Valacyclovir; Valtrex

What is this drug used for?

• Used to treat herpes zoster, herpes sores near the mouth, or certain other herpes infections.
• This drug is used to treat chickenpox.
• This drug may also be used for other indications. Consult your doctor.

What should I tell my doctor BEFORE taking this drug?

• If you have an allergy to this drug, any of its ingredients, other drugs, foods or substances. Tell your doctor about your allergies and how they have manifested.

Combining this drug with certain drugs and conditions may be unfavorable.

Tell your doctor and pharmacist about all medicines you take (both prescription and over-the-counter, natural products and vitamins) and any health problems you have. You need to make sure that this drug is safe for your conditions and in combination with other drugs you are already taking. Do not start or stop taking any drug or change the dosage without your doctor’s advice.

What do I need to know or do while taking this drug?

• Tell all your health care workers that you are taking this drug. These are doctors, nurses, pharmacists and dentists.
• Do not take this drug for longer than the length of time your doctor has prescribed.
• If you are using this drug to treat cold sores, it will not treat the sores. Consult your doctor.
• This drug does not cure herpes infections. Consult your doctor.
• If you have genital herpes, this drug cannot prevent it from spreading. Any sexual contact should be avoided if there are ulcers or other signs of genital herpes. Genital herpes can be transmitted even in the absence of signs of infection. Do not have sexual intercourse without using a latex or polyurethane condom. Consult with your doctor.
• If you are 65 years of age or older, use this drug with caution. You may experience more side effects.
• Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding. The benefits and risks for you and your child will need to be discussed.

What side effects should I report to my doctor immediately?

WARNING. In rare cases, this drug can cause serious and sometimes deadly side effects in some patients. Call your doctor right away or get medical help if you have any of the following signs or symptoms that could be associated with serious side effects:

• Signs of an allergic reaction such as rash, hives, itching, red and swollen skin with blisters or peeling, possibly in combination with fever, wheezing or wheezing, tightness in the chest or throat, difficulty breathing, swallowing or speaking, unusual hoarseness, swelling in the mouth, face, lips, tongue or throat.
• Signs of kidney problems, including not passing urine, changes in the volume of urine, blood in the urine, or rapid weight gain.
• Confusion of consciousness.
• Changes in behavior.
• Mood changes.
• Hallucinations (a person sees or hears something that is not in reality).
• Difficult speech.
• Unsteady gait, difficulty moving, or muscle stiffness.
• Seizures.
• Some people have had a very serious and sometimes fatal blood problem, such as thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS), while taking this drug. Feeling very tired or weak, bruising or bleeding, dark urine or yellow skin or eyes, pale skin, changes in urine output, blurred vision, changes in muscle strength on one side of the body, difficulty speaking or thinking, problems with balance or high body temperature, consult a doctor immediately.

What are some other side effects of this drug?

Any medicine can have side effects. However, for many people, side effects are either minor or non-existent. Contact your doctor or seek medical attention if these or any other side effects bother you or do not go away:

• Headache.
• Nausea or vomiting.
• Pain in the intestines.
• Diarrhea.
• Feeling tired or weak.
• Menstrual pain.

This list of possible side effects is not exhaustive. If you have any questions about side effects, please contact your doctor. Talk to your doctor about side effects.

You can report side effects to the National Health Board.

You can report side effects to the FDA at 1-800-332-1088. You can also report side effects at https://www.fda.gov/medwatch.

What is the best way to take this drug?

Use this drug as directed by your doctor. Read all the information provided to you. Strictly follow all instructions.

• Take this drug with or without food.
• Drink plenty of non-caffeinated fluids, unless your doctor tells you to drink less fluids.
• To treat a cold, chickenpox, or genital herpes, start this drug as soon as possible as soon as symptoms appear. This drug may not work as well if you start taking it too late.
• If you are on dialysis and take this drug on the day of dialysis, take it after dialysis. If you have any questions, please consult your doctor.
• Keep taking this drug as instructed by your doctor or other health care professional, even if you feel well.
• If you cannot swallow tablets, a liquid form of the drug (suspension) may be made. Consult your doctor or pharmacist.

Liquid (suspension):

• Shake the solution (suspension) well before use.
• Liquid doses should be measured with caution. Use the dispenser that comes with the medicine. If the dispenser is not provided in the package, ask the pharmacist for a dosing agent for this drug.

What if I miss a dose of a drug?

• Take the missed dose as soon as you can.
• If it’s time for your next dose, don’t take the missed dose and then go back to your regular dosing schedule.
• Do not take 2 doses or an additional dose at the same time.

How do I store and/or discard this drug?

Tablets:

• Store at room temperature in a dry place. Do not store in the bathroom.

Liquid (suspension):

• In case of dissolution (suspension) of the drug tablets, the solution (suspension) should be stored in the refrigerator. Do not freeze. Throw away any unused servings after 28 days.

All forms:

• Keep all medicines in a safe place. Keep all medicines out of the reach of children and pets.
• Dispose of unused or expired drugs. Do not empty into a toilet or sewer unless instructed to do so. If you have any questions about disposing of medicines, ask your pharmacist. Drug disposal programs may be in place in your area.

General information about medicines

• If your health does not improve or even worsens, see your doctor.
• Do not give your medicine to anyone and do not take other people’s medicines.
• Some medicines may come with other patient information leaflets. If you have any questions about this drug, talk with your doctor, nurse, pharmacist, or other health care professional.
• Some medicines may come with other patient information leaflets. Check with your pharmacist. If you have any questions about this drug, talk with your doctor, nurse, pharmacist, or other health care professional.
• If you think you have overdosed, call a poison control center or get medical help right away. Be prepared to tell or show what drug you took, how much, and when it happened.

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This summary information includes a summary of the diagnosis, treatment, and/or drug product. It is not intended to be a comprehensive source of data and should be used as a tool to help the user understand and/or evaluate potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a particular patient. It should not be considered medical advice or a substitute for medical advice, diagnosis or treatment provided by a physician based on a medical examination and assessment of the patient’s specific and unique circumstances. Patients should consult with their physician for full information about their health, medical issues, and treatment options, including any risks or benefits regarding the use of medications. This information is not a guarantee that a treatment or drug is safe, effective, or approved for a particular patient. UpToDate, Inc. and its subsidiaries disclaim any warranties or liabilities related to this information or its use. The use of this information is subject to the Terms of Use found at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.

Last revision date

2022-12-26

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Date last updated

Monday, December 12, 2022

Valtrex side effects and interactions and how to avoid them – Product Information

Home >> Product Information >> Valtrex Side Effects and Interactions and How to Avoid Them

Product Information

If you’ve ever had shingles or herpes, you know how annoying these infections can be. Valtrex is an antiviral drug that can help relieve the symptoms of viral infections such as shingles or chickenpox. This article provides an overview of drug information, including Valtrex side effects, warnings, and drug interactions that you should be aware of before taking your medication.

What is Valtrex?

Valtrex belongs to a group of medicines called antivirals that work by slowing the growth and spread of viruses such as herpes simplex, shingles, and chickenpox. Valtrex is the brand name for valaciclovir hydrochloride. The brand and generic drugs are chemically the same, work the same way, and are equally effective in treating infections caused by the herpes virus.

Herpes virus infections include herpes, genital herpes, shingles, and chicken pox. Valtrex does not cure herpes infection, but can treat symptoms like herpes sores and blisters. Valtrex is not an over-the-counter drug, so if you have a herpes infection you will need a prescription.

Some people may need seven to 10 days for Valtrex to start working, while others may experience relief of their symptoms in a day or two. The time it takes for symptoms to go away will depend on your age, the severity of your symptoms, and your metabolism.

Valtrex for herpes

Many people wonder if Valtrex will stop the formation of herpes. Valtrex should be taken at the first signs of herpes (tingling, itching, burning) to prevent them from worsening and to prevent the development of other herpes. However, it is not a cure for herpes. He considers them only as a symptom of a viral infection.

Valtrex for genital herpes

Even if you are taking Valtrex, an outbreak is possible. If you are taking Valtrex repeatedly for genital herpes and you have an outbreak, it is important to avoid sexual contact with your partner so that the virus does not spread to them. Even if you don’t have an outbreak, using condoms is a good idea to prevent transmission.

Also, if you’re wondering if your non-infected partner can take Valtrex without getting hurt, the answer is no. Those who do not have the herpes simplex virus should not take medication because of what they do not have. This can cause serious side effects or health problems.

Common side effects of Valtrex

Taking Valtrex may cause side effects such as:

• Headache
• Nausea
• Stomach or abdominal pain
• Dizziness
• Vomiting
• Weight gain
• Irritability
• Fatigue
• Trouble sleeping
• Trouble concentrating
• Loss of appetite
• Skin rash
• Bleeding gums
• Sore throat
• Diarrhea
• Joint pain

It is not known if Valtrex causes other side effects such as hair loss, weight gain, dry mouth, or any other symptoms not listed by the FDA and Drug Administration (FDA). This is not a complete list of side effects. Other side effects may occur. If you have any questions about the side effects of Valtrex, check with your doctor.

Frequently asked question about Valtrex: Does it cause frequent urination? This will not necessarily make you urinate more, but you should drink plenty of water while taking Valtrex so that your kidneys can process it as best as possible. Therefore, this extra hydration can lead to frequent urination.

Serious side effects of Valtrex

Although rare, Valtrex may cause more serious side effects that may require medical attention, including:

• Hallucinations
• Aggressive behavior
• Seizures
• Confusion
• Speech problems
• Unusual bruising or bleeding
• Depression
• Low blood cell count
• Painful periods in women

If you are taking Valtrex and you have any of these symptoms, you should seek medical attention as soon as possible.

If you have any signs of an allergic reaction, such as difficulty breathing, hives, or swelling of your face, mouth, or throat, you should seek emergency medical attention right away.

Other serious side effects that can potentially occur with Valtrex include:

• Inflammation of the liver.
• Renal toxicity
• Renal failure
• A serious blood disorder called thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS).

Some patients are more susceptible to these serious side effects than others. Check with your doctor to see if you are at risk.

These side effects are very rare. Antivirals are effective in treating viral infections, but after long-term use, they can eventually weaken the immune system by affecting immune cells. It’s usually only a problem for older people and people with weakened immune systems. Even if it’s not usually taken for a long period of time, if your doctor really wants you to take it for a long time, that’s fine. Some studies have even shown that long-term use of Valtrex is well tolerated by healthy individuals.

If you have side effects from Valtrex and are thinking about stopping your medication, you should call your doctor before doing so. Abruptly stopping Valtrex may cause new side effects or worsen symptoms. If you stop taking Valtrex earlier than you should, your viral infection may get worse because the medication hasn’t had a chance to work properly.

Warnings Valtrex

Although Valtrex is very effective in treating herpes infections, not everyone should take it.

Underlying health conditions

You should talk to your doctor before taking Valtrex if you have any of the following conditions:

• HIV : HIV suppresses the immune system and increases the chance of contracting other diseases. People with HIV taking Valtrex significantly increase their risk of getting TTP/HUS, a serious blood disorder.
• Kidney or bone marrow transplant : If you are taking Valtrex and are considering a bone marrow or kidney transplant, you should talk to your doctor. Your risk of getting TTP/HUS will increase significantly if you take Valtrex at the time of your transplant.
• Kidney problems or kidney disease : People with kidney problems or kidney disease may experience worsening of symptoms or kidney failure if they take Valtrex.

Because of its ability to adversely affect the kidneys, some people wonder if Valtrex also affects the liver, but studies have shown that this is rarely associated with mild liver damage and resolves quickly.

Age restrictions

If you are over 65, it is best to consult your doctor before taking Valtrex. Older people may have a higher risk of side effects and are more prone to kidney problems because of this. This does not mean that you cannot take Valtrex over the age of 65. Your doctor may simply recommend a lower dose.

Pregnancy and breast-feeding

Pregnant women If they plan to take Valtrex, they should talk to their doctor to find out how it might affect their pregnancy. In laboratory studies, Valtrex did not affect the fetus; however, Valtrex has not been properly tested in pregnancy, says Vikram Tarugu, MD, gastroenterologist and CEO of South Florida Detox. The safety of Valtrex during breastfeeding has not been proven. Breastfeeding women should consult with their physician about other approaches to breastfeeding.

Valtrex interactions

Taking Valtrex at the same time as certain other medicines may cause additional side effects or complications. You should consult your doctor before taking Valtrex if you are taking any of these medicines:

• Foscarnet
• Aciclovir
• Famciclovir
• Nephrotoxic agents
• Bacitracin

9000 5 Methotrexate

• Cancer drugs
• Arthritis drugs
• Medicines used to prevent organ transplant rejection
• Also, talk to your doctor if you have recently received a varicella-zoster (live) or shingles (live, Zostavax, not Shingrix) vaccine.

Bring a complete list of all prescription drugs and supplements you take to your doctor so he or she can decide if Valtrex is right for you.

There are currently no known interactions between Valtrex and grapefruit or grapefruit juice, which can sometimes affect how much medication stays in the body at one time.

On the other hand, it is better to avoid alcohol while taking Valtrex. This is because the combination of alcohol and Valtrex can cause excessive drowsiness and dizziness.

When it comes to caffeine and Tylenol, the two most likely to be consumed while taking Valtrex, they can be taken unless directed otherwise by a healthcare professional.

How to avoid the side effects of Valtrex

1. Take the right dose at the right time of the day.

This is the best way to avoid the side effects of Valtrex. Here are the standard doses of Valtrex for adults and children:

Valtrex dosages
Condition	Age group 900 66	Standard dosage
Herpes	Adults	2 g two once a day for one day with an interval of 12 hours
Herpes	Children (12 years and older)	2 g twice a day for one day every 12 hours
Herpes zoster	Adults	1 g thrice daily for 7 days
Chickenpox	Children with normal immune function (aged 2 years to	Dose based on weight (20 mg/kg) administered 3 times a day for 5 days. Total dose should not exceed 1 gram thrice a day. day within 5 days
Genital herpes (initial episode)	Adults	1 g twice a day for 10 days

These dosages are only general recommendations. If your doctor prescribes Valtrex differently, you must follow his instructions. Valtrex is most effective when started immediately after symptoms appear, so contact your doctor immediately if you have symptoms. It is safe to take Valtrex every day if you are instructed to do so.

If you miss Valtrex, you should take your next dose as soon as possible. Taking the missed dose as soon as you remember what you missed will help prevent your herpes infection from getting worse. Taking two doses at the same time can cause serious side effects, so if you miss a dose, take only one dose if you remember. However, if it is almost time for your next dose, skip the missed dose and return to your regular schedule.

It is also important to remember that Valtrex has an expiration date of like any other medicine.