Aciclovir Tablets

Aciclovir tablets are a prescription-only medication used to treat viral infections caused by herpes simplex viruses (HSV), including cold sores and genital herpes. They can be taken during an initial or recurrent outbreak of symptoms, or as a way to avoid outbreaks. They usually come in 200mg and 400mg tablets but can be prescribed at 800mg in some cases.

Aciclovir is an antiviral medication. Antiviral means it helps kill certain viruses and shortens an infection caused by them.

Is there a cream available?

As well as tablets, aciclovir comes as a cream. Aciclovir cream can be used by itself for outbreaks of cold sores or genital herpes and is used topically, meaning you spread it over the affected area. The cream can be bought online or over-the-counter in pharmacies. You shouldn’t use aciclovir tablets and cream at the same time.

Since it works to kill viral infections, it can be used for a few different conditions caused by viruses, including:

• genital herpes
• cold sores
• shingles and chickenpox
• some eye infections

Aciclovir for herpes

HSV causes genital herpes. It’s impossible to cure genital herpes completely, but you can treat the symptoms. Since aciclovir is effective against HSV, it can be used to treat and prevent genital herpes.

Aciclovir for cold sores

Similar to genital herpes, cold sores are also caused by HSV infections. So you can apply a cream that contains aciclovir to treat cold sores. You might need aciclovir tablets instead if the infection does not clear, or to prevent it from coming back in future.

Aciclovir for shingles or chickenpox

Aciclovir can also be used to treat shingles and chickenpox infections. For both conditions, early aciclovir treatment can reduce how long the outbreaks last. For chickenpox, aciclovir can also reduce the number of lesions that the outbreak causes.

Aciclovir works by stopping the herpes virus from multiplying after symptoms have started. It does this by stopping it from making the DNA it needs to make copies of itself and spread. This helps to heal your infection and helps your immune system fight the virus quicker than it would without help.

How effective is aciclovir?

Studies show that compared to taking a placebo, aciclovir can clear up an infection faster, reduce pain and itching, and reduce the number of lesions formed in patients with an initial or recurrent outbreak. It was also well-tolerated (most people had little to no side effects).

How long does aciclovir take to work?

It will usually take up to 3 days to start seeing your symptoms reduce on aciclovir. It usually takes a 5-day course of aciclovir to treat an outbreak. A single tablet will reach full concentration in your blood in 2 hours.

Aciclovir comes in the following doses:

• 200mg tablets
• 400mg tablets
• 800mg tablets
• 5% cream

200mg tablets

This dosage is used for treating non-genital herpes (cold sores) and for preventing herpes in people who are immunocompromised.

400mg tablets

This dose can be used to treat an outbreak of cold sores or genital herpes when taken three times a day. It’s also the standard dose for suppressing genital herpes when taken twice a day.

800mg tablets

This dose is used to treat shingles and chickenpox or to avoid an outbreak if you’ve been exposed to someone with either of these conditions. A doctor won’t usually prescribe this for genital herpes and taking more than your prescribed dose for genital herpes is unsafe.

Doses for treating cold sores

Either the 200mg tablet or the 5% aciclovir cream is used for treating a cold sore outbreak.

You can either order aciclovir online and get a prescription from an online doctor service like ZAVA or see your GP who can give you a prescription. Once you’ve got a prescription, you can get it filled at most UK pharmacies.

Can you get aciclovir over-the-counter?

Aciclovir tablets are prescription only, so a doctor needs to check to make sure they’re safe for you to use. The cream is available over-the-counter in pharmacies or online.

You should take aciclovir tablets with a glass of water. The usual dose is: one aciclovir 400mg tablet, 3 times a day and you should wait 8 hours between each dose. An example of the times you need to take each aciclovir tablet looks like this:

• 7am for the first tablet
• 3pm for the second tablet
• 11pm for the third tablet

You should take aciclovir 400mg tablets for 5 days, or for as long as your doctor tells you to if needed.

If you cannot swallow tablets, you can dissolve an aciclovir tablet in a small amount of water and drink all of the liquid.

Are there foods to avoid on aciclovir?

Aciclovir is not affected by food, so you can eat before or after you take your tablet. There is some evidence that taking 3g or more of lysine a day can help you avoid and recover from herpes outbreaks. Foods rich in lysine that can help with herpes, include:

• meats like red meat, pork, poultry, and fish
• cheese, especially parmesan
• eggs
• foods made out of soy

Taking aciclovir when pregnant

Aciclovir is fine to take when pregnant, but your doctor may adjust your dose slightly. During late pregnancy (after 36 weeks) the doctor may increase your dose for herpes suppression.

ZAVA can offer genital herpes treatment during pregnancy but not cold sore treatment.

What should I do if I forget to take it?

If you forget to take one of your aciclovir tablets, take it as soon as you remember. But if it’s nearly time for you to take your next tablet, then skip the missed dose so you do not take too much. Do not take 2 aciclovir tablets (a double dose) to make up for a missed dose.

What should I do if I take too much?

If you're worried you've taken more aciclovir than you need, you should contact your doctor straight away. Side effects of too much aciclovir include feeling sick or confused.

Common side effects of aciclovir include:

• headache
• dizziness
• nausea
• vomiting
• diarrhoea
• stomach pains
• itching
• tiredness
• fever

Uncommon side effects of aciclovir include:

• itchy rash
• hair loss

You can find out more about the side effects of aciclovir, including rare side effects, by reading the patient information leaflet that comes with your aciclovir tablets.

If you experience any side effects while taking aciclovir, get in touch with your doctor as soon as possible. You can also report your side effects to the MHRA yellow card scheme online.

Most people can take aciclovir to treat genital herpes or cold sores. But the amount of aciclovir you can take will depend on how healthy you are and other medicines you might be taking at the same time.

Do not take aciclovir if you:

• are allergic to aciclovir or any of the other ingredients
• are allergic to similar antivirals, like valaciclovir

Speak to your doctor before taking aciclovir if you:

• have or have ever had kidney (renal) problems
• are older than 65 years of age
• are pregnant or trying to get pregnant
• are breastfeeding

If you are not sure whether you can take aciclovir, or whether you need it, you can take a genital herpes test or speak to a doctor.

Some other medications can interact with aciclovir and affect how it works. Tell your doctor if you are taking or have recently taken any other medication, including ones without a prescription.

In particular, tell your doctor if you have taken:

• probenecid for gout
• cimetidine for stomach ulcers
• mycophenolate mofetil after having an organ transplant

Aciclovir is not the only treatment for herpes. If you do not think aciclovir tablets are right for you, there may be an alternative treatment you can take. Other treatments that do the same thing as aciclovir include:

• valaciclovir
• famciclovir

Aciclovir and valaciclovir are equally as effective at treating herpes. Speak to your doctor if you’d prefer an alternative treatment to aciclovir and they can give you advice on what to do next.

Aciclovir or valaciclovir?

Aciclovir:

• From £19.95 at ZAVA
• 54% effective*
• A dose of 400mg twice a day for five days is used to treat regular genital herpes outbreaks

Valaciclovir:

• From £29.95 at ZAVA
• 59% effective*
• A dose of 500mg twice a day for three days is used to treat regular genital herpes outbreaks

*taken from a study comparing aciclovir and valaciclovir. Shows the percentage of patients who had no herpes visible in their system after five days.