Aciclovir 400mg Tablets at 123 Meds

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Aciclovir 400mg Tablets

Category	Details
Product Name	Aciclovir
Brand Names	Zovirax, Cymex Ultra, Virasorb
Active Ingredient	Aciclovir
Also Called	Acyclovir (in the US)
Available Strengths	400mg
Available As	Tablets
Used For	Genital Herpes, Cold Sores
Class of Medicine	Anti-Viral

What is Aciclovir?

Aciclovir is an antiviral medicine used to treat and suppress genital herpes in adults. It stops the virus from multiplying, easing discomfort, speeding healing and reducing future outbreaks and transmission risk when taken daily.

What is Aciclovir Used For?

Treating outbreaks: Reduces pain and speeds recovery.
Suppressing outbreaks: Daily tablets lower recurrence and help prevent passing the virus to partners.

How Aciclovir Works

Aciclovir is converted inside infected cells to its active triphosphate form, which blocks the viral DNA polymerase enzyme and prevents replication of the herpes virus.

Genital Herpes: Symptoms, Treatment & Prevention

Typical symptoms include painful genital blisters, itching and flu-like feelings.
Antiviral tablets shorten outbreaks and reduce their frequency.
Avoid sex during symptoms and use condoms between episodes.

Can You Buy Aciclovir Tablets Over the Counter?

No. Oral aciclovir is a prescription-only medicine (POM) in the UK.

Alternative Medications

Valaciclovir (including Valtrex) may be used if more convenient dosing is preferred.

Treatment of an outbreak

400 mg three times a day for 5 days

Suppression

400 mg twice daily.

Your prescriber will review the need every 6–12 months.

Take with water and drink plenty of fluids.

If a dose is missed, take it as soon as possible unless it is nearly time for the next.

Active ingredient: Aciclovir.

Inactive ingredients vary by manufacturer but generally include lactose, microcrystalline cellulose and magnesium stearate.

Check the patient information leaflet if you have allergies or intolerances.

Common: headache, nausea, diarrhoea, abdominal pain, dizziness, tiredness.

Seek immediate medical help by contacting 999 if you notice allergic reactions, confusion, hallucinations or kidney-related symptoms such as painful or reduced urination.

Good hydration helps reduce kidney risk.

What precautions should be taken when using Aciclovir?
Take Aciclovir exactly as prescribed. Do not skip doses or take more than recommended. Drink plenty of water throughout the day to stay well hydrated and protect your kidneys.
What are the limitations of Aciclovir?
Aciclovir is generally well tolerated, but it can cause side effects such as headache, nausea or diarrhoea. These are usually mild in nature. Rarely, it may affect kidney function, particularly if you are dehydrated or have existing kidney problems. Always tell your 123Meds prescriber about any medical conditions or other medicines before starting treatment and seek urgent medical advice if you experience any persistent side effects.
How quickly does Aciclovir work?
Aciclovir usually begins to work within 24–48 hours. Symptoms typically improve over 5–10 days. Complete the full course even if you start to feel better sooner.
Is Aciclovir an antibiotic or steroid?
No. Aciclovir is an antiviral medicine used to treat herpes infections such as genital herpes and cold sores.
Who cannot take Aciclovir?
Do not take Aciclovir if you are allergic to aciclovir, valaciclovir or any of the ingredients in the tablets. People with kidney problems or who take medicines that affect the kidneys may need to speak to their GP for appropriate treatment options.
How long is Aciclovir suitable for?
For a first genital-herpes outbreak, treatment usually lasts 5–10 days. For recurrent outbreaks it is typically 5 days.
For prevention (suppression), a lower daily dose may be taken for several months if recommended by your prescriber or GP.
How does Aciclovir work?
Once inside the body, Aciclovir is converted to an active form that blocks the viral DNA polymerase enzyme, stopping the herpes virus from making new copies of itself.
Can I have sex while taking Aciclovir?
If you are treating genital herpes, avoid sexual contact until all sores have healed. Even when no symptoms are visible, use condoms to reduce the risk of passing the virus to a partner.
Can lifestyle changes prevent cold sores or herpes infections?
Lifestyle changes cannot eliminate herpes, but managing triggers can reduce outbreaks:
Get adequate rest and manage stress.
Eat a balanced diet.
Use a lip balm with SPF 30 or higher to protect against sun-induced outbreaks.
Does Aciclovir interact with foods or drinks?
There are no known food interactions. Alcohol does not directly affect Aciclovir, but heavy drinking can dehydrate you and make it harder for your body to fight infections.
Does Aciclovir interact with other medicines?
Yes. Tell your 123Meds prescriber about all medicines and supplements you take. Drugs such as probenecid, cimetidine, or other medicines that can affect the kidneys (for example, high-dose NSAIDs) may increase the risk of side effects.
Is Aciclovir an antifungal?
No. Aciclovir treats viral infections such as herpes. Fungal infections like thrush require an antifungal medicine.
What can I do if the treatment is not working?
If symptoms do not improve or worsen after completing the prescribed course, contact your doctor. They may adjust the dose or suggest a different treatment.
Can I drive or ride a bike while taking Aciclovir?
Aciclovir can occasionally cause dizziness. If this happens, avoid driving, cycling or operating machinery until you feel well.
What happens if I miss a dose?
Take it as soon as you remember unless it is nearly time for your next dose. Do not take two doses at once.
What should I do if I take too much Aciclovir?
Taking too much can be harmful. If you think you have taken an overdose, call NHS 111 or go to the nearest A&E department immediately.
How do I know if Aciclovir is working?
Your symptoms should start to improve within a few days. If they do not, or if they worsen, contact your GP or NHS111.
How should I store Aciclovir?
Store below 25 °C in a dry place away from light and moisture, and keep out of the sight and reach of children.