What Is Aciclovir Used For? Your Guide To The Antiviral Treatment

Scott McDougallMPharmDirector & Registered Manager

Reviewed on: 25 May 2022

If you are suffering from genital herpes, you may have heard of available treatments such as Aciclovir. But what is Aciclovir used for exactly?

In this comprehensive guide, we’ll be covering everything you need to know about this medication, such as how to take Aciclovir, how it works and the different Aciclovir tablets uses. We’ll also be discussing how long Aciclovir tablets take to work, and whether you can buy Aciclovir tablets over the counter in the UK.

Read on to find out more about Aciclovir.

What is Aciclovir?

Aciclovir (also known as Acyclovir or the brand name Zovirax) is a prescription-only antiviral medication that is used to prevent or treat infections from the herpes simplex virus (HSV). This includes genital herpes and cold sores. It may also be used to treat shingles or chickenpox, which are caused by a virus from the same family.

Aciclovir usually comes in the form of tablets, but can also come as a capsule, cream, liquid that you drink (oral suspension) or as an injection. Aciclovir injections are usually only done in hospitals in rarer circumstances.

Aciclovir cannot completely cure herpes, but it will stop the growth of the virus and suppress the symptoms — helping to treat outbreaks. Aciclovir can also be used to prevent recurrent outbreaks.

It is one of the most popular treatments in the UK for genital herpes.

What is Aciclovir used for?

Aciclovir is used to prevent or treat viral infections from the herpes simplex virus (HSV). In particular, it is used to treat outbreaks of genital herpes.

Genital herpes is a very common sexually transmitted infection (STI) in the UK. It passed on through vaginal, anal and oral sex. Like many STIs, herpes is highly contagious and can be spread by any direct contact with the affected areas.

Genital herpes appears as small blisters or red sores on your genitals, bottom, anus, or thighs. The herpes virus can also manifest as cold sores in the mouth area. You can find out more about genital herpes here.

Aciclovir is an antiviral medication that can be used to treat outbreaks or prevent them. It does this by targeting the enzyme that the herpes virus needs to replicate and grow.

By stopping any further production of this enzyme, the virus cannot reproduce and create more blisters. This allows the immune system to fight the remaining virus and should end the outbreak, clearing up any signs of genital herpes or cold sores. You can find aciclovir to treat cold sores here.

Does Aciclovir work?

In short, yes. Aciclovir is extremely effective at treating and preventing viral infections such as those caused by the herpes simplex virus, including genital herpes.

It is important to take Aciclovir exactly as your doctor or pharmacist tells you too.

The medication works best when the amount of the drug in your body is kept at a constant level. That is why it is so important to follow your prescription instructions, and to take Aciclovir at evenly spaced intervals. To help you remember, it is a good idea to take it at the same time each day.

You should continue to take Aciclovir until the prescribed amount is finished. Do not change your dose, skip any doses, or stop this medication early without your doctor's approval.

Find out more information about different Aciclovir doses here.

If you don’t take Aciclovir as advised, it may not work effectively and you may risk not getting rid of the infection.

How do you use Aciclovir?

If you’re wondering how to use Aciclovir, don’t worry — this medication is easy to use.

Here are some tips to make sure that you take Aciclovir correctly:

You should swallow each tablet with water (or a non-alcoholic drink). Each dose of Aciclovir should be taken with a large glass of water.
Make sure you drink plenty of fluids throughout the course of your treatment: Aciclovir can put stress on the kidneys, so it is important to remain thoroughly hydrated while taking the tablets.
Aciclovir can be taken with or without food — it’s up to you. However, taking it with or after a meal may help to reduce the chances of experiencing a side effect like nausea or an upset stomach. Read more about Aciclovir side effects here.
You should start to take Aciclovir as soon as you notice symptoms of herpes. These can include visible blisters, a burning sensation and experiencing pain when you urinate or have intercourse.
Follow the instructions you have been given by your doctor or pharmacist; the doses and treatment plan will change according to your individual condition. If you are unsure or worried that you have forgotten what your doctor said, there will be directions on your prescription label.
Continue to take Aciclovir until the full prescribed amount is finished. Do not change your dose, skip any doses, or stop taking your medication early without your doctor's approval.
If you have forgotten to take an Aciclovir tablet, you should take it as soon as possible. This is to maintain the levels of Aciclovir in your body, which will help you to fight the viral infection more effectively. Then take the next dose at the right time.
Do not take two doses at the same time to make up for a missed dose. If you only remember the next time you are due to take an Aciclovir tablet, you should just take one tablet as usual.
If you think you have taken too many Aciclovir tablets, contact your doctor immediately. Signs of an overdose include effects on the stomach and intestines (like feeling or being sick) and effects on the nervous system, such as confusion.

If you are concerned in any way about Aciclovir, or you think that your condition is getting worse (or not improving), then you should speak to your doctor or pharmacist for further guidance.

You can drink alcohol with Aciclovir, in moderation.

How long for Aciclovir tablets to work?

If you begin to take Aciclovir tablets as soon as any symptoms appear, an outbreak will often disappear within one to two days.

If it’s your first time taking Aciclovir, your first course will probably last for around 10 days.

The results are not always instantaneous, so it is important to complete your course of treatment as instructed by your doctor or pharmacist.

If you are experiencing a recurring outbreak, you should start taking Aciclovir as soon as possible after symptoms have started to present themselves.

Signs of an imminent recurrent outbreaks are tingling or itching sensations. If you start taking Aciclovir tablets as soon as you notice these signs, the blisters associated with genital herpes may not occur at all.

This is because Aciclovir targets the enzyme that the herpes simplex virus needs to replicate and grow. By stopping any further production of this enzyme, the virus cannot reproduce and create more blisters. This then allows the immune system to effectively fight the remaining virus and end the outbreak.

Can I buy Aciclovir tablets over the counter?

No, you cannot buy Aciclovir over the counter in the UK.

Aciclovir is a prescription-only treatment. This means that it must be prescribed by a doctor or pharmacist.

You can purchase Aciclovir 400 mg tablets to treat genital herpes through The Independent Pharmacy following a free online consultation. You’ll just need to answer a few quick questions first so that our qualified prescribers can be sure that this is the right treatment for you before we prescribe it.

Once we do, we can get your treatment sent out to you for next day delivery. We offer a fast and secure online service and delivery straight to your door. We don't include any branding or pharmacy logo on our packaging, meaning you can get your treatment delivered discreetly.

Can I take paracetamol with Aciclovir?

If you need to take pain relief while you're taking Aciclovir, then it's absolutely fine to take paracetamol. There is no interaction between paracetamol and Aciclovir, so it is safe to take them at the same time.

It is also usually fine to take other painkillers like ibuprofen, but it’s a good idea to check with your pharmacist or doctor first if you've got (or have ever had) any problems with your kidneys.

Aciclovir should not be taken with some medicines that you get on prescription.

You should inform your doctor and pharmacist about any other medicines you are currently taking or are planning to take before you start a course of Aciclovir. This includes herbal or complementary medicines.

Aciclovir and other conditions

Aciclovir is an antiviral medication that can be used to treat or prevent a number of infections.

Depending on the condition, a larger or smaller Aciclovir dosage will be prescribed by your doctor or pharmacist. There are multiple different Aciclovir doses that are used to treat a range of infections and conditions. You can find out more about the different strengths of this medication on our Aciclovir dosages page.

Below we’ve covered what Aciclovir can and cannot help with.

Aciclovir and shingles

Aciclovir can be used to treat shingles. Shingles is a painful condition that is caused by the same virus (the varicella-zoster virus) that causes chickenpox. Anyone can get it, but it's most common in older people.

Aciclovir may be prescribed to treat shingles and shorten the length and severity of the infection.

A typical shingles dosage will be 800 mg of Aciclovir every four hours, five times per day for seven to ten days.

Aciclovir and cold sores

You can take Aciclovir tablets to treat cold sores. A dosage of 200 mg or 400 mg may be prescribed to you depending on your condition.

Aciclovir can also be purchased in the form of a topical cream to apply directly to cold sores. Aciclovir 5% cream is the first-line treatment for recurrent outbreaks of cold sores and is available at The Independent Pharmacy.

In some cases, tablets may be more effective than cream. However, they are usually prescribed for more severe cold sore outbreaks.

Aciclovir and chickenpox

Aciclovir may be used to treat chickenpox as well. Chickenpox usually gets better by itself within a week without needing to see a GP, so you may not be prescribed Aciclovir. In many cases, your doctor may just suggest taking paracetamol to help with discomfort, using cooling creams or gels from your pharmacy, and drinking plenty of fluid to avoid dehydration.

However, in certain cases, some people may need medicine like Aciclovir to prevent complications (such as if you have a weakened immune system).

It is best to start taking Aciclovir as soon as your first signs of chickenpox appear; it may not be effective if your treatment is started more than 24 hours after onset of symptoms.

A typical dosage of Aciclovir for chickenpox will be 800 mg four times a day for five days.

Aciclovir and thrush

Aciclovir is used to treat viral infections. Thrush is a fungal infection, which means that Aciclovir is an unsuitable treatment and will not help to alleviate or cure the symptoms of thrush.

Thrush can usually be treated with antifungal medicine from a pharmacist, doctor or sexual health clinic. You can read more about the symptoms and treatment of thrush on our thrush treatments page.

Summary

Aciclovir is a safe and effective antiviral medicine that is used to prevent or treat viral infections from the herpes simplex virus (HSV), like genital herpes or cold sores.

It may also be used to treat other conditions, such as chickenpox or shingles, which are caused by a virus similar to HSV.

Depending on the condition you are trying to treat or prevent, the dosage and type of Aciclovir you are prescribed may vary. It’s always important to take your medication exactly as your doctor or pharmacist suggests to ensure that you are treating your condition as safely and effectively as possible.

Aciclovir is a prescription-only treatment, which means you can’t buy Aciclovir tablets over the counter in the UK. This means that it must be prescribed by a doctor or pharmacist.

If you think Aciclovir might be the right treatment for you, you can buy Aciclovir 400 mg tablets through The Independent Pharmacy to treat outbreaks of genital herpes.

You’ll just need to answer a few questions first on our free online consultation form (which is quick and easy to do). This will allow our qualified prescribers to make sure that this is the right treatment for you.

Once prescribed, we can get your treatment sent out to you for next day delivery. Our delivery service is fast, secure and discreet — we don't include any branding or pharmacy logo on our packaging, meaning you can get your treatment delivered discreetly.