Aciclovir 400mg Tablets

Price range: £19.99 through £48.00

Aciclovir 400mg Tablets are prescription antiviral tablets used to treat and prevent herpes virus infections such as cold sores, genital herpes, and shingles.
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Aciclovir 400mg Tablets are prescription antiviral medicines used to treat and prevent infections caused by the herpes simplex and varicella-zoster viruses. These viruses cause conditions such as cold sores, genital herpes, shingles (herpes zoster), and chickenpox. Aciclovir works by targeting the virus directly at the site of replication, which helps shorten the duration and severity of symptoms while reducing the risk of further transmission.

Doctors also prescribe Aciclovir to prevent recurring outbreaks in people who experience frequent episodes of genital herpes or cold sores. Moreover, it is often recommended for patients with weakened immune systems to protect them from potentially serious viral infections.

Because this medicine is effective at both treating active infections and preventing future episodes, it offers flexibility for short- or long-term use. Taking the tablets at the first sign of an outbreak can help control symptoms before they worsen.

How It Works

Aciclovir belongs to a group of medicines called antiviral agents. It interferes with the virus’s ability to replicate its DNA. Specifically, it becomes active once inside infected cells and blocks the function of viral DNA polymerase. As a result, the virus cannot multiply, allowing the body’s immune system to regain control and clear the infection more effectively.

Why Choose Aciclovir

Patients choose Aciclovir for its proven efficacy, especially in managing herpes-related infections. It is well tolerated and has a well-established safety record. Because it works selectively on virus-infected cells, it rarely causes side effects in healthy tissues. Furthermore, it is one of the few antivirals available in oral tablet form, offering a convenient and non-invasive treatment option.

For people at risk of frequent outbreaks or those recovering from more severe infections, Aciclovir offers both protection and symptom relief. When taken as prescribed, it can significantly reduce downtime and discomfort caused by herpes viruses.

Important Note

Aciclovir 400mg Tablets are Prescription Only Medicines (POM) in the UK.
You should only take this medication under the supervision of a licensed healthcare provider. Always follow the dosage and course length exactly as directed, and speak to your GP or pharmacist if you have concerns about side effects or other health conditions.

Directions

Always read and follow the patient information leaflet (PIL) provided with the medicine before use.

  • General treatment dose: 400mg three times a day for 5–10 days (as advised).

  • Suppressive therapy: 400mg twice a day to reduce recurrence.

  • Administration: Swallow whole with water. Take doses evenly spaced throughout the day.

  • Hydration: Drink plenty of fluids while taking Aciclovir.

  • Do not exceed the dose prescribed by your doctor.

Used To Treat

  • Genital herpes

  • Cold sores

  • Shingles (herpes zoster)

  • Chickenpox

  • Recurrent herpes virus outbreaks

How Does It Work?

Aciclovir works by blocking the action of viral DNA polymerase — an enzyme essential for viral replication. This stops the herpes virus from multiplying, giving the immune system a chance to fight off the infection more effectively and reducing symptoms like pain, itching, and sores.

Ingredients

  • Active Ingredient: Aciclovir 400mg

  • Other Ingredients May Include: Microcrystalline cellulose, magnesium stearate, sodium starch glycolate, colloidal anhydrous silica, and starch. Always check packaging.

Side Effects

Common side effects:

  • Headache

  • Nausea

  • Dizziness

  • Diarrhoea

  • Abdominal pain

Serious side effects (rare):

  • Allergic reactions (swelling, rash, breathing difficulties)

  • Confusion or hallucinations (mainly in elderly or unwell patients)

  • Kidney problems

If you experience any side effects or symptoms while taking this medication, please consult your GP or a healthcare professional.

Who Should Avoid

Do not take Aciclovir 400mg Tablets if you:

  • Are allergic to aciclovir or any ingredients listed

  • Have kidney disease (unless under medical supervision)

  • Are taking other medications that affect renal function

Speak to your doctor before use if you:

  • Are pregnant or breastfeeding

  • Are elderly

  • Have dehydration or are on fluid-reducing medications

Storage Instructions

  • Store below 25°C in a dry place

  • Keep tablets in original packaging

  • Keep out of sight and reach of children

  • Do not use after expiry date on the pack

  • Yes, Aciclovir can be taken with or without food. Swallow the tablets whole with a glass of water.
  • No, Aciclovir does not cure herpes. It helps manage outbreaks by reducing symptoms and viral shedding.
  • Aciclovir typically begins to reduce symptoms within 1 to 2 days. It's important to take the full course even if symptoms improve early
  • Aciclovir is generally considered safe in pregnancy and while breastfeeding, but always consult your doctor before use.
  • Take it as soon as you remember. If it’s nearly time for your next dose, skip the missed one. Don’t double up.