Drug Interactions and Medical Precautions with Aciclovir
Most people arriving on this page want one answer, so here it is. There is no known direct interaction between aciclovir and alcohol. NHS guidance says you can eat and drink normally while taking aciclovir, including drinking alcohol. It is also important to drink plenty of water while taking aciclovir tablets, particularly if you have kidney problems.
That does not mean there is nothing else to think about. If you are taking aciclovir because you have a viral infection, you may already be feeling unwell, and you may also be taking other medicines. This guide covers alcohol, the main medicine interactions, common side effects and the practical things worth knowing during a course.
Key things to know
- Alcohol is not known to have a direct interaction with aciclovir, and NHS guidance says you can drink alcohol while taking it
- Aciclovir is mainly removed from the body through the kidneys, so hydration is particularly important with tablets, especially if you have kidney problems
- The NHS specifically lists probenecid, cimetidine and mycophenolate mofetil as medicines that may not mix well with some aciclovir tablets
- There are no specific foods you need to avoid with aciclovir
- Other medicines can also matter, particularly with higher doses or intravenous aciclovir used in hospital, so tell your prescriber or pharmacist about everything you take
Can You Drink Alcohol on Aciclovir?
Yes. You can drink alcohol while taking aciclovir. NHS guidance says you can eat and drink as normal, including alcohol. There is no specific recommendation to avoid alcohol because of a direct interaction with aciclovir.
The same answer applies whichever spelling you searched. Aciclovir is the UK name, while acyclovir is commonly used in the United States. They refer to the same antiviral medicine.
The more useful point is to pay attention to how you feel. Aciclovir tablets can cause side effects such as headache, dizziness, nausea, diarrhoea and tiredness. If alcohol makes you feel worse, you may prefer to avoid it until you feel better.
Staying hydrated is also important while taking aciclovir tablets. This matters particularly if you have kidney problems or have been prescribed a higher dose.
What Alcohol Can Still Do During an Outbreak
There is no need to treat alcohol as a direct aciclovir interaction. However, if you are already unwell, drinking heavily may leave you feeling worse.
| What may happen | Why it matters during treatment |
|---|---|
| You may become dehydrated | Drinking enough water is important while taking aciclovir tablets, particularly if you have kidney problems |
| You may feel more tired or unwell | Aciclovir itself can cause tiredness, dizziness, headache or nausea in some people |
| You may notice side effects more | Alcohol can make some people feel unwell or dizzy, which may be harder to manage if you already have medicine related side effects |
| You may be recovering from an infection | Your illness itself may affect how you feel, so you may simply prefer to avoid alcohol until you recover |
None of this means that a glass of wine is known to be dangerous with aciclovir. NHS guidance allows alcohol while taking the medicine. If you choose to drink, stay within the usual UK guidance for alcohol and make sure you are drinking enough water.
Can You Drink Alcohol With Aciclovir 800mg?
Aciclovir 800mg is used for conditions such as shingles and chickenpox, as well as some other herpes virus infections. The dose and treatment schedule depend on the condition being treated, so follow the instructions given to you.
There is still no specific NHS warning against alcohol with aciclovir. However, higher doses of aciclovir make good hydration particularly important, and the medicine should be used carefully in people with kidney problems.
If you have shingles, you may also be taking painkillers or other medicines. Those medicines may have their own alcohol warnings. So, if you are taking several medicines at once, check with a pharmacist rather than assuming that the aciclovir answer applies to everything you are taking.
The practical answer to questions such as aciclovir tablets and alcohol, or specifically aciclovir 800mg and alcohol, is that aciclovir itself does not have a known direct alcohol interaction. Your overall health, hydration and any other medicines you take still matter.
Aciclovir Cream and Alcohol
There is no known interaction between aciclovir cream and alcohol. NHS guidance does not list any medicines that affect aciclovir cream or eye ointment.
Very little of the medicine from a topical product is expected to reach the bloodstream compared with tablets, so alcohol is not a specific concern with the cream.
Remember that aciclovir cream should not be used inside the mouth or nose, in or near the eyes, or in other areas not listed in the product instructions.
Aciclovir Interactions: A Short List, and Why It Is Short
Aciclovir has a relatively short list of important interactions for routine oral treatment. The reason is linked to how the medicine leaves the body.
Aciclovir is mainly eliminated unchanged through the kidneys. Some medicines can affect this process and change the amount of aciclovir in the blood. Probenecid and cimetidine, for example, reduce the renal clearance of aciclovir and can increase its exposure.
This does not mean aciclovir has no other possible interactions. The medicine formulation, dose and the health of your kidneys all matter, which is why your prescriber or pharmacist should know about all the medicines you take.
The Three Medicines Commonly Listed as Interactions
| Medicine | What it is used for | Why it matters |
|---|---|---|
| Probenecid | Gout | Can reduce the removal of aciclovir by the kidneys and increase aciclovir levels |
| Cimetidine | Stomach ulcers and some stomach conditions | Can reduce the removal of aciclovir by the kidneys and increase aciclovir levels |
| Mycophenolate mofetil | Preventing rejection after a transplant | Taking it with aciclovir can affect the levels of aciclovir and the inactive metabolite of mycophenolate |
These three medicines are specifically listed by the NHS for some aciclovir tablets. They do not automatically mean that you cannot take aciclovir. Your doctor or pharmacist can decide whether the combination is suitable for you and whether any monitoring is needed.
Cautions That Mostly Apply in Hospital
There are additional interaction and monitoring considerations, particularly with intravenous aciclovir used in hospital.
For example, medicines that can affect kidney function, such as ciclosporin and tacrolimus, may require particular care with intravenous aciclovir. Intravenous aciclovir can also interact with medicines such as lithium and theophylline in ways that may require monitoring.
These are not reasons for someone taking a standard short course of tablets for a cold sore to panic. They show why it is important not to treat every interaction list online as if it applies in exactly the same way to every form and dose of aciclovir.
If you take several medicines, particularly medicines that affect your kidneys, tell your prescriber or pharmacist before starting aciclovir.
Supplements, Including the Nattokinase Question
Questions about a possible aciclovir and nattokinase interaction also come up online. There is no well established interaction between the two listed in the standard NHS aciclovir interaction information.
However, that does not mean every supplement has been studied alongside every medicine. Nattokinase is a supplement made from fermented soya beans, and it may affect blood clotting. The more relevant questions are about whether it is suitable alongside medicines that affect blood clotting.
The broader point applies to supplements in general. Interaction information for supplements can be less complete than for licensed medicines. Tell your prescriber or pharmacist about everything you take, including herbal products and supplements bought from a health food shop. The NHS specifically recommends doing this when taking aciclovir.
Foods to Avoid With Aciclovir
There are no specific foods that you need to avoid with aciclovir. NHS guidance says you can eat and drink as normal while taking it.
Aciclovir tablets can be taken according to the instructions on your prescription or medicine leaflet. If you are unsure whether to take your particular product with food, check the leaflet or ask a pharmacist.
You may also come across advice about arginine and lysine when searching for foods and cold sores. Arginine is found in foods such as nuts, seeds and chocolate, while lysine is found in foods including dairy products, fish and some legumes.
This is a separate question from how aciclovir works. There is not enough evidence to recommend avoiding particular foods as part of aciclovir treatment. You do not need to remove chocolate or other foods from your diet simply because you are taking aciclovir.
Aciclovir Side Effects
Like any medicine, aciclovir can cause side effects, although not everyone gets them. The effects can vary depending on whether you are using the cream, tablets or intravenous treatment.
| Formulation | What may happen |
|---|---|
| Cream | Mild burning or stinging at the application site can occur |
| Tablets | Headache, dizziness, nausea, vomiting, diarrhoea, stomach pain, tiredness, rash and photosensitivity may occur |
| Intravenous, in hospital | Kidney problems and nervous system effects can occur, particularly in people with risk factors such as kidney impairment |
Aciclovir tablets can cause a skin reaction after exposure to light, so take sensible precautions in strong sunlight if you notice this effect.
If you feel dizzy or faint after taking aciclovir tablets, NHS advice is to avoid driving, cycling or using machinery until you feel better.
When to Get Urgent Help
Serious side effects are uncommon, but it is useful to know what to look out for.
Call 999 if you develop signs of a severe allergic reaction, such as swelling of the throat or tongue, a raised itchy rash or difficulty breathing.
Contact NHS 111 or a doctor promptly if you develop signs of a serious side effect, such as passing very little or no urine, yellowing of the skin or whites of the eyes, unusual bruising or significant confusion.
These symptoms can have causes other than aciclovir, so they do not automatically mean the medicine is responsible. They do, however, need medical advice.
What to Actually Avoid During a Course
A few practical points are more useful than a long list of things you supposedly cannot do while taking aciclovir.
- Do not let yourself become dehydrated, particularly while taking aciclovir tablets. Drinking plenty of water is especially important if you have kidney problems
- Do not take two doses together to make up for a missed dose. If it is nearly time for your next dose, skip the missed dose and take the next one as usual
- Do not change or stop your prescribed treatment without speaking to your prescriber, unless you have been told to stop because of a serious reaction
- Do not use aciclovir cream inside your mouth or nose, in or near your eyes, or in any other area not listed in the product instructions
- Do not share your aciclovir tablets with someone else. The dose and treatment length depend on the condition being treated
- Do not assume that every medicine or supplement is suitable to take alongside aciclovir. Check with a pharmacist or prescriber if you take other medicines
Who Needs Extra Care
Some people need extra care when taking aciclovir, particularly those with reduced kidney function.
This is because the kidneys remove most of the aciclovir from the body. Your prescriber may need to consider your kidney function when deciding which dose is appropriate. Staying well hydrated is also particularly important if you have kidney problems.
Older adults may also need particular consideration because kidney function can decrease with age.
If you take medicines that affect your immune system, have a condition that affects your immune system, or take several other medicines, make sure your prescriber knows. The right dose and treatment length depend on the infection being treated and your individual circumstances.
If you are pregnant or breastfeeding, speak to your doctor or pharmacist before taking aciclovir tablets. NHS guidance says aciclovir can usually be used during pregnancy, but it is still sensible to check with a healthcare professional first.
Medical Disclaimer
This page provides general information about aciclovir, alcohol and medicine interactions. It is not personal medical advice, and it does not recommend a dose for anyone.
Always tell your prescriber or pharmacist about every medicine and supplement you take before starting aciclovir, including medicines bought without a prescription and herbal products. Do not stop, start or change a medicine based only on what you read here.
Seek urgent medical help for signs of a severe allergic reaction. Contact NHS 111 or a doctor if you develop serious symptoms such as passing very little or no urine, jaundice, unusual bruising or significant confusion. Suspected side effects can be reported through the MHRA Yellow Card Scheme.
