Valaciclovir for Herpes

Valaciclovir is an antiviral medication prescribed to treat genital herpes and reduce how long and severe future flare-ups (outbreaks) are. Valaciclovir tablets are available in 500mg doses. The usual dose for a genital herpes outbreak is one 500mg tablet twice a day.

Valaciclovir is often used to treat flare-ups of conditions caused by herpes simplex virus 2 (HSV-2), the most common strain of HSV responsible for causing genital herpes. Valaciclovir can also be prescribed for other viral conditions, such as:

• cold sores (also caused by the herpes simplex virus, more commonly HSV-1)
• chickenpox
• shingles
• eye infections caused by the herpes simplex virus

Valaciclovir works by stopping the virus from replicating, making it easier for your immune system to get rid of the infection. It does this by stopping an enzyme in the DNA called polymerase from working as it should. This enzyme is essential for the replication of the virus, allowing it to make copies of itself and spread. By stopping the growth of the virus, valaciclovir:

• helps your immune system control the virus
• shortens the healing time of genital herpes sores
• reduces pain
• lowers the risk of spreading the herpes virus

Valaciclovir is known as a ‘prodrug’ because once it is inside the body, it is converted into its active form, aciclovir. Valaciclovir is more potent than its active form, so it can be taken less frequently and has a simpler dosing regimen.

How long does valaciclovir last?

Valaciclovir treatment for genital herpes can last for:

• 5 to 10 days if it is your first infection
• 3 to 5 days to treat a recurrent infection (flare-up)

In people with normal kidney function, aciclovir, the medication valaciclovir is converted into once inside your body, has a half-life of around 3 hours. Half-life is the time it takes for a medication to reduce by half in your body.

How long does valaciclovir take to work?

Valaciclovir starts to work as soon as you take the first dose, but you may not notice an improvement in your symptoms for 2 to 3 days.

It’s important to get genital herpes treatment as soon as you notice symptoms because antiviral medications like valaciclovir can shorten the duration of your first outbreak by 2 to 4 days, and future outbreaks by around 2 days.

How effective is valaciclovir?

Valaciclovir is considered an effective genital herpes treatment, reducing transmission of HSV-2 by up to 48% in healthy adults. One study found that 79% of people had no recurrent genital herpes infections while taking valaciclovir compared to 52% of people given a placebo.

An earlier study looking at the effectiveness of valaciclovir for reducing genital herpes transmission found that it reduced the risk of transmitting symptomatic genital herpes by 75%, with only 4 out of 743 susceptible partners developing infection compared to 16 out of 741 in a placebo group (group given no medication).

Valaciclovir tablets should be swallowed whole with a glass of water.

How to take valaciclovir for a current genital herpes outbreak

The usual dose for treating a current outbreak is one 500mg valaciclovir tablet twice a day, taken around 12 hours apart.

If this is your first outbreak, you’ll take valaciclovir for 5 days or up to 10 days. Your doctor will let you know how long you need to take it for based on the severity of your symptoms.

If this is a recurrent infection, you’ll take valaciclovir for 3 to 5 days.

How to take valaciclovir to prevent recurrent genital herpes

A doctor may prescribe valaciclovir to stop genital herpes from coming back. The usual dose is one 500mg tablet once a day. If you have frequent outbreaks, you may be prescribed one 250mg tablet twice a day instead. You’ll need to take it for as long as your doctor tells you to.

Your doctor may advise you to stop taking valaciclovir every 6 to 12 months to reassess the frequency of outbreaks.

Whether you take valaciclovir to treat a current genital herpes outbreak or prevent recurrent outbreaks, you should take the medication exactly as your doctor has told you to.

What if I miss a dose of valaciclovir?

If you forget to take valaciclovir, take it as soon as you remember, unless it is almost time for your next dose. If it is, skip the missed dose and take the next one as usual.

Do not take a double dose to make up for a missed one.

What if I take too much valaciclovir?

Valaciclovir is not usually harmful unless you take too much over several days. If you take too many tablets, you may get the following symptoms:

• feeling sick (nausea)
• being sick (vomiting)
• kidney issues
• confusion
• agitation
• hallucinations
• becoming unconscious

If you have taken too much valaciclovir, especially if you notice any of these symptoms, speak to your doctor or pharmacist for advice.

When prescribing valaciclovir to you, the doctor will choose the most appropriate dose based on:

• whether this is your first outbreak or a recurrence
• how often you get recurrent outbreaks
• your immune status
• whether you need it to prevent a future outbreak
• your kidney function – you may need a lower dose if your kidneys are not working properly

If you have certain medical conditions, such as if you are immunocompromised, the dose may be adjusted according to your medical history and current infection status.

Valaciclovir starting dosage

Generally, the starting dose of valaciclovir is 500mg twice a day to treat a first or recurrent outbreak. The length of time you’ll take it is generally shorter for a recurrent outbreak. If you’re taking valaciclovir to prevent a herpes outbreak, the starting dosage is 500mg once a day.

This dosage could be higher if you have certain medical conditions, such as HIV, or lower if you have poor kidney function.

Maximum valaciclovir dosage

For genital herpes, the maximum dosage is 1g per day, taken as one 500mg tablet twice a day. This dose is given for suppressive therapy to people with weakened immune systems.

Advantages of each valaciclovir dosage

The dosage strategy for valaciclovir can help to manage symptoms and lower the risk of side effects. It can also be used to tailor the treatment to your needs. The advantages of each dose are discussed below:

500mg twice daily

Given to treat the first genital herpes outbreak in most people. It reduces viral replication quickly, speeding up recovery and managing symptoms.

500mg once daily

Used to suppress the HSV-2 infection, reducing viral shedding and how serious future outbreaks are. This can help slow down or stop outbreaks altogether.

1g once daily

Prescribed to people with compromised immunity, including HIV-positive patients, to prevent future outbreaks. A higher dosage is often needed in people who are immunocompromised, as the body will find it harder to get rid of the infection.

Can you change your valaciclovir dosage?

It may be possible to change your valaciclovir dose, but you will need to speak to your doctor to see if this is possible and appropriate. You should not adjust your dose on your own.

Valaciclovir is a prescription-only medication that can be requested from reputable online doctor services, like ZAVA, or on the NHS. Because you will need a doctor’s approval to obtain it, you cannot buy valaciclovir over the counter.

Can I buy valaciclovir online?

Yes, you can buy valaciclovir 500mg tablets online from ZAVA for your first or recurrent outbreak, or to suppress future outbreaks by:

1. Simply filling out a short online health questionnaire.
2. One of our doctors will review your responses and confirm your suitability.
3. Your medication will be discreetly delivered by Royal Mail to an address of your choice, or you can choose to collect it from your local Post Office.

By ordering online from ZAVA, you do not have to wait for an appointment with a doctor or visit a sexual health clinic if you do not feel comfortable speaking to someone in person. We provide a convenient and completely confidential service where you can get the treatment you need, delivered in discreet packaging. You can also message a doctor for free through your private patient account if you need further advice on taking your medication.

Can I buy valaciclovir over the counter?

No, valaciclovir is a prescription-only medication, so it is not available over the counter.

Can I get valaciclovir on the NHS?

Yes, valaciclovir may be available on the NHS, but you will need to make an appointment with your doctor or at a sexual health clinic.

Like all medications, valaciclovir can cause side effects, but not everyone will get them.

Common side effects, affecting up to 1 in 10 people, include:

• feeling sick (nausea)
• being sick (vomiting)
• dizziness
• diarrhoea
• skin reaction to sunlight exposure
• rash
• itching

Uncommon side effects, affecting up to 1 in 100 people, include:

• feeling confused
• seeing and hearing things that are not there (hallucinations)
• drowsiness
• tremors
• agitation
• low blood cell count on blood tests
• shortness of breath
• stomach discomfort
• hives
• blood in the urine
• kidney pain

Rare side effects that may affect up to 1 in 1000 people, include:

• unsteadiness when walking and a lack of coordination
• slow, slurred speech
• seizures
• altered brain function
• unconsciousness
• confusion or disturbed thoughts
• severe allergic reaction
• kidney failure

It is important to familiarise yourself with the potential side effects valaciclovir can cause, so you know what to look out for and how you can manage them. For example, more than 1 in 10 people experience headaches when taking valaciclovir. A full list of valaciclovir side effects can be found in the patient information leaflet that comes with the medication.

How long do valaciclovir side effects last?

Most valaciclovir side effects are temporary and can last from a few days to a week after stopping the medication. However, not everyone will get them.

What to do if you get valaciclovir side effects

If you get any of the following serious side effects, you should stop taking valaciclovir and call 999 or get someone to take you to A&E, as they could be signs of an allergic reaction:

• flushing
• itchy skin rash
• swelling of lips, face, neck, and throat, causing difficulty breathing
• drop in blood pressure leading to collapse

Most mild side effects can be managed at home by:

• taking over-the-counter painkillers to manage pain, such as headaches
• drinking plenty of clear fluids
• getting some rest
• eating smaller, more frequent meals

Valaciclovir may not be suitable for everyone. Do not take valaciclovir if you:

• are allergic to any of the ingredients in the medication
• have developed an extended rash associated with fever, enlarged lymph nodes, increased levels of liver enzymes, and or eosinophilia after taking valaciclovir

Before taking valaciclovir, tell your doctor if you:

• have kidney problems
• have liver problems
• are over 65 years of age
• have a weakened immune system

Valaciclovir and other medications

Let your doctor know if you are or are going to take any prescribed, over-the-counter, or herbal medications before taking valaciclovir.

You should also let them know if you are taking any medication that affects the kidneys, such as:

• aminoglycosides
• organoplatinum compounds
• Iodinated contrast media
• methotrexate
• pentamidine
• foscarnet
• ciclosporin
• tacrolimus
• cimetidine
• probenecid

Valaciclovir during pregnancy and breastfeeding

Valaciclovir is not usually recommended during pregnancy. If you are or think you may be pregnant or you are breastfeeding, ask your doctor or pharmacist for advice before taking valaciclovir.

Valaciclovir is not the only genital herpes treatment available. At ZAVA, we can offer the following alternatives:

Aciclovir

Aciclovir is a prescription-only medication that contains the active ingredient aciclovir. The usual dose is one 200mg tablet taken 5 times a day or one 400mg tablet taken 3 times a day. Aciclovir is the active ingredient that valaciclovir is converted to when you take it.

Famciclovir

Famciclovir is similar to valaciclovir because it's also a prodrug, except it is converted into a different antiviral medication called penciclovir once in the body. It works by preventing the genital herpes virus from replicating and spreading, helping your immune system fight off the infection. The typical dose is one 250mg tablet 3 times a day for 5 days.

If you’re not sure if you have genital herpes, you can visit a sexual health clinic or request an at-home genital herpes test kit. To use our at-home test kit, you must have active sores at the time of testing. The kit is supplied with everything you need to take a swab and send your sample back to our partner laboratory. You’ll receive your results within 2 to 3 days of the lab receiving your sample.

Valaciclovir vs aciclovir

Valaciclovir and aciclovir are both antiviral medications that are used to treat herpes simplex virus infections, like genital herpes. The difference is that valaciclovir is a prodrug that is converted into aciclovir in the body.

Clinical studies have found that taking valaciclovir 500mg tablets twice a day was as effective and well-tolerated in the treatment of the first genital herpes outbreak as taking aciclovir 200mg tablets 5 times a day.