Aciclovir, also spelled acyclovir, is available in the UK in several strengths and formulations. Aciclovir tablets are available in 200mg, 400mg and 800mg strengths, alongside 5% cream and 3% eye ointment formulations. The appropriate strength and formulation depend on the infection being treated and individual factors such as age, kidney function and the specific treatment plan.
Using UK prescribing and medicines information, this guide explains what each strength and formulation is generally used for. It is designed to help UK adults understand a prescription, product listing or online treatment option for conditions such as cold sores, genital herpes, shingles and chickenpox.
Treatment suitability depends on an individual clinical assessment. This article does not provide personal dosing instructions, so always follow the prescription or product instructions you have been given.
It also covers branded and generic aciclovir, treatment in children, how aciclovir compares with valaciclovir, typical pricing, and how to obtain treatment through EverydayMeds' UK online consultation service.
Aciclovir Tablet Strengths: 200mg, 400mg and 800mg
Aciclovir tablets are available in three strengths in the UK: 200mg, 400mg and 800mg. Which strength is prescribed depends on the infection being treated, the treatment regimen and individual factors such as kidney function. The same strength can be used for more than one condition, so the tablet strength alone does not tell you which infection is being treated.
| Strength | Typically associated with |
|---|---|
| 200mg | Herpes simplex infections, including genital herpes, and some prevention regimens |
| 400mg | Herpes simplex infections, including recurrent genital herpes and suppressive treatment; it may also be used as part of other treatment regimens |
| 800mg | Shingles and chickenpox, as well as some herpes simplex treatment or suppression regimens depending on the product and clinical situation |
This table shows general prescribing uses and is not a substitute for your prescription. Your prescriber decides the appropriate strength and dosing schedule for your individual situation.
Aciclovir 200mg: Cold Sores and Herpes Simplex
Aciclovir 200mg tablets are used to treat herpes simplex infections, including genital herpes. They can also be used in some regimens to prevent recurrent herpes simplex infections. The exact treatment schedule depends on the condition being treated and your individual circumstances.
If you have been prescribed aciclovir for an active herpes simplex infection, follow the dose and frequency on your prescription rather than choosing a strength yourself.
Aciclovir 400mg: Genital Herpes and Suppressive Treatment
Aciclovir 400mg tablets are used for herpes simplex infections, including recurrent genital herpes and treatment intended to reduce future recurrences.
Some people may be prescribed 400mg as part of a suppressive treatment regimen. The appropriate dose and frequency depend on the reason for treatment and individual circumstances.
The strength on the packet does not tell you how often the tablets should be taken. Always follow the instructions from your prescriber.
Aciclovir 800mg: Shingles and Chickenpox
Aciclovir 800mg tablets are commonly used in adult treatment regimens for shingles and chickenpox. Some UK product information also lists 800mg tablets for certain herpes simplex treatment and suppression regimens, so 800mg is not limited to shingles or chickenpox.
For shingles, treatment should start as early as possible when antiviral treatment is indicated. UK product information states that treatment gives better results when started as soon as possible after the shingles rash appears. For chickenpox in immunocompetent adults, treatment should begin within 24 hours of the rash appearing when aciclovir treatment is appropriate.
If you think you have shingles or chickenpox and may need antiviral treatment, seek medical advice promptly rather than waiting for symptoms to settle on their own.
Aciclovir Cream and Eye Ointment: How They Differ From Tablets
Aciclovir is available in oral, topical and eye formulations. Aciclovir 5% cream is used for some herpes simplex skin infections, including cold sores, depending on the specific product. Some cold sore products are applied several times a day, so follow the instructions supplied with the product you are using.
Aciclovir cream is intended for use on the skin and should not be put inside the mouth, in the eye or on other mucous membranes unless the specific product information says otherwise.
Aciclovir eye ointment is a separate 3% formulation used for herpes simplex infections affecting the eye. It is not interchangeable with 5% aciclovir skin cream. Suspected herpes simplex eye infections need prompt medical assessment because the infection can affect the cornea and vision.
Do not use the skin cream in the eye or substitute it for an eye treatment.
Aciclovir in Children
Aciclovir treatment in children depends on the child's age, weight and the infection being treated. Children may receive different regimens from adults, so their prescription should always be followed rather than using adult strength guidance.
For some infections, UK product information uses different doses according to age or weight. For example, chickenpox treatment may use age based dosing or a weight based calculation, with a maximum dose specified in the product information.
If your child has been prescribed aciclovir, use the exact strength and instructions provided by their prescriber or pharmacist.
Generic Aciclovir vs Zovirax
Zovirax is a branded medicine containing aciclovir. Generic aciclovir medicines also contain aciclovir as the active ingredient.
An authorised generic medicine must meet the required quality standards. Generic and branded medicines can have different inactive ingredients, tablet appearance, packaging and price, even though they contain the same active ingredient.
If you have been prescribed generic aciclovir, use it according to the instructions on your prescription. If you have questions about switching between products, ask a pharmacist.
How Aciclovir Compares to Valaciclovir
Valaciclovir is a related antiviral medicine that is converted into aciclovir in the body. It has better oral bioavailability than aciclovir, which means the body can absorb more of the active medicine after an oral dose. This allows valaciclovir to be used less frequently for some conditions.
The two medicines are not simply different strengths of the same product. Which one is appropriate depends on the infection being treated, your medical history and the treatment regimen chosen by your prescriber.
Available Treatment Options, Other Medicines, and Pricing
| Product | Price |
|---|---|
| Aciclovir 5% Cream | From £8.99 |
| Aciclovir Tablets | From £12.99 |
| Valaciclovir | From £18.99 |
| Valtrex | From £34.99 |
Prices shown are subject to change. Check the current price and available formulations at checkout.
How to Get Aciclovir Through EverydayMeds
Getting aciclovir through EverydayMeds starts with a short online questionnaire about your symptoms. A UK registered prescriber reviews the information and decides whether treatment is suitable and, where appropriate, which strength and formulation may be prescribed.
The outcome depends on your individual clinical assessment, so a particular medicine or strength cannot be guaranteed.
