Aciclovir

Safety First: Who Should Not Use Aciclovir Without Medical Advice?

Aciclovir is prescription only in the UK for good reason, because the dose, form, and duration need to match the infection and the person taking it.

The main absolute contraindication is a known hypersensitivity to aciclovir, valaciclovir, or any excipient in the product.

Caution is especially important in older people, anyone with renal impairment, dehydration, neurological conditions, pregnancy or breastfeeding, and anyone taking medicines that can affect the kidneys.

Seek urgent help if there is a severe rash, facial swelling, breathing difficulty, confusion, or reduced urine output.

Before you take aciclovir, check:

• Do you have kidney problems?
• Are you pregnant or breastfeeding?
• Are you taking any other medicines?
• Are you able to drink enough fluids?

Basic Aciclovir Information

• INN (International Nonproprietary Name): Aciclovir, also commonly spelled Acyclovir in the United States, Canada, and some other regions.
• Brand names available in United Kingdom: Zovirax, generic aciclovir.
• ATC Code: J05AB01.
• Forms & dosages: Tablets 200mg, 400mg, 800mg; cream 5%; suspension 200mg/5ml; ointment 5%; intravenous vials 250mg, 500mg, 1000mg.
• Manufacturers in United Kingdom: GlaxoSmithKline, Sandoz/Novartis, Mylan, Ranbaxy/Sun Pharma, Sanofi, and other generic suppliers.
• Registration status in United Kingdom: Prescription only.
• OTC / Rx classification: Rx — prescription only in most countries, including the UK.

What Aciclovir Is And How It Works

INN, Generic Naming, And ATC Classification

Aciclovir is an antiviral medicine used against herpes viruses, and the American spelling is Acyclovir.

Its ATC code is J05AB01, which places it in antivirals for systemic use, while topical formulations sit under D06BB for dermatological antivirals.

In practice, that means tablets and suspensions are used for infections inside the body, while cream is used on the skin for local lesions such as cold sores.

INN

The international generic name used across countries.

ATC code

A medicine classification code used to group drugs by therapeutic use.

Antiviral

A medicine that helps control viral replication.

Topical formulation

A cream or ointment applied to the skin or eye area where prescribed.

UK Brand Names, Forms, And Strengths Available

Common UK Products

Patients in the UK will usually see Zovirax or generic aciclovir on a prescription, and the same medicine is also stocked by major pharmacy chains and online pharmacies.

For shoppers comparing aciclovir tablets UK options, the main oral strengths are 200mg, 400mg, and 800mg.

Aciclovir cream is normally 5%, while aciclovir suspension is 200mg/5ml and is useful when swallowing tablets is difficult.

When Aciclovir Is Used In NHS And Private Care

Approved Indications

Aciclovir is commonly used for herpes simplex infections, genital herpes, shingles, and chickenpox.

Topical aciclovir cold sore cream is used for local treatment of cold sores, and cream may also be used for genital lesions where appropriate.

Eye ointment is only used when prescribed, usually for specialist-managed eye infections.

In NHS-style prescribing, the medicine is chosen based on the site of infection, how severe the outbreak is, and whether the aim is treatment or suppression.

That is why a pharmacist or prescriber will often ask when symptoms started, how often the outbreaks happen, and whether the person has any kidney problems or other risk factors.

Standard Adult And Paediatric Dosing In The UK

Oral Regimens

For herpes simplex and initial genital herpes, the standard adult regimen is 200mg five times daily for 5 to 10 days.

For suppression of recurrent genital herpes, common regimens are 400mg twice daily or 200mg three to five times daily, sometimes for up to 6 to 12 months.

For shingles, the usual adult regimen is 800mg five times daily for 7 to 10 days.

For chickenpox, 800mg four times daily for 5 days may be used if started early, ideally within 24 hours of the rash.

Paediatric Dosing

Children are dosed by body weight, and younger children may be given suspension rather than tablets.

• Weight-based dosing is used rather than a fixed adult dose.
• Suspension is often chosen for infants and small children.
• The child’s age, weight, and infection type all matter.
• Dosing should be confirmed by a clinician or pharmacist before use.

Dose Adjustments: Kidneys, Age, And Hydration

Renal Impairment And Older Adults

Aciclovir is eliminated by the kidneys, so dose reduction matters when renal function is reduced.

For severe impairment, oral dosing frequency is often halved.

Older adults need closer monitoring because reduced kidney function can increase the risk of neurotoxicity and other adverse effects.

Hydration Advice

Good hydration helps reduce kidney stress, especially with tablets or intravenous treatment.

Ask a pharmacist or GP before starting if you have:

• Kidney disease
• Dehydration
• Confusion or a neurological illness
• Frailty

Missed Doses, Overdose, And What To Do Next

Missed Dose Guidance

If a dose is forgotten, take it as soon as remembered if it is only a few hours late.

If the next dose is nearly due, skip the missed one and return to the normal schedule.

Never take two doses together.

Overdose Warning Signs

Overdose symptoms may include agitation, confusion, lethargy, and signs of renal dysfunction.

Severe cases may need urgent assessment, IV fluids, and sometimes haemodialysis because the medicine is cleared through the kidneys.

What If I Miss A Dose?

Take it when you remember unless the next dose is close, then skip it and continue as normal.

Side Effects: What Is Common And What Needs Urgent Help?

Common Side Effects

The most common side effects are nausea, vomiting, diarrhoea, abdominal pain, headache, dizziness, fatigue, and local skin irritation with cream.

Some people also notice mild rash or itching where the cream is applied.

Rare But Serious Reactions

Confusion, a widespread rash, an allergic reaction, or kidney-related symptoms need prompt attention, especially in older people and those with renal impairment.

Interactions: Medicines, Alcohol, And Everyday Habits

Drug Interactions

The main concern is with nephrotoxic medicines or anything that increases renal stress.

That includes prescription drugs, over-the-counter products, and supplements, so it is worth telling the pharmacist everything being taken.

Food, Drink, And Lifestyle

There are no major food restrictions with aciclovir, but hydration really matters.

Alcohol can worsen dehydration, especially if someone already feels unwell with fever or a sore throat from chickenpox.

• Tell your pharmacist if you take kidney-affecting medicines.
• Mention any non-prescription painkillers.
• Include herbal products and supplements.
• Say if you have had recent vomiting, diarrhoea, or poor fluid intake.

How To Use Aciclovir Cream, Tablets, And Suspension Correctly

Oral And Topical Technique

Tablets work best when taken regularly and spaced through the day, because the doses are meant to keep antiviral activity steady.

For aciclovir cream, apply it to clean, dry skin and keep it away from the eyes unless the product is specifically an eye preparation.

For suspension, shake the bottle if the label instructs it and measure doses with an oral syringe rather than a kitchen spoon.

Infection Control And Self-Care

Simple hygiene helps reduce spread, especially with cold sores and genital herpes.

• Wash hands before and after applying cream.
• Do not share towels, lip balm, or razors.
• Keep the tube tightly closed after use.
• Avoid touching cold sores and then touching the eyes.

Safety In Pregnancy, Breastfeeding, And Immunocompromised Patients

Pregnancy And Breastfeeding

Pregnant or breastfeeding patients should seek clinician or pharmacist advice before using aciclovir.

The aim is usually careful risk-benefit counselling rather than alarm, because the right choice depends on the infection, the stage of pregnancy, and whether treatment is needed urgently.

Immunocompromised Patients

People with weakened immunity have a higher risk of complications and may need clinician-led treatment rather than simple self-care.

Can I Use Aciclovir If I Am Pregnant?

Speak to your GP, NHS service, or pharmacist first, so the safest option can be checked for your situation.

Uk Access: NHS Prescriptions, Pharmacies, And Online Ordering

How People Get Aciclovir In The UK

Aciclovir may be prescribed by a GP, urgent care clinician, sexual health clinic, or hospital specialist, and NHS electronic prescriptions are widely used.

Community pharmacies are often the place where patients get the practical counselling that makes treatment easier to use correctly.

In our online pharmacy, aciclovir is available without a prescription, with discreet delivery to United Kingdom in 5-14 days.

Where It Is Commonly Supplied

Patients may see it at Boots, LloydsPharmacy, Superdrug, independent pharmacies, and regulated online pharmacies.

Nhs Cost Differences Across The Uk

England Versus The Devolved Nations

In England, NHS prescription charges may apply, while prescriptions are free in Scotland, Wales, and Northern Ireland.

Some people in England are exempt, so it is always worth checking eligibility before paying.

Typical Price Considerations

Private prescriptions and pharmacy supply services can differ in price from NHS dispensing, and the final cost depends on the product, pack size, and whether a consultation is included.

How Aciclovir Compares With Alternatives

NHS Prescribing Alternatives

Valaciclovir is a prodrug with improved oral bioavailability, so it can be more convenient for some people.

Famciclovir has similar uses but a different regimen, while penciclovir is topical.

Docosanol is used for cold sore care in some markets, but it is not a standard UK equivalent.

• The person struggles with frequent tablets.
• There is a kidney issue that changes the dosing plan.
• The infection is being managed as suppression rather than an acute outbreak.
• A topical option is enough for a mild cold sore.

Storage, Regulation, And Patient Counselling Points

Storage And Handling

Store aciclovir under 25°C, protect it from light and moisture, and do not freeze the cream.

Always close the tube tightly after use, and keep medicines out of reach of children.

UK Regulation And Counselling

Aciclovir is MHRA-regulated and prescription only, which is why pharmacist counselling is so useful when symptoms start or repeat prescriptions are being arranged.

In UK practice, people often ask the pharmacy team about cold sores, genital herpes, and which formulation is most appropriate for the symptoms they have.

Can I Keep Aciclovir In A Bathroom Cabinet?

It is not ideal because bathrooms are often warm and damp, so a cool, dry cupboard is better if the product directions allow it.

• Do store it under 25°C.
• Do protect it from moisture and light.
• Do not freeze the cream.
• Do not leave it in a bathroom cabinet if it gets damp.

Delivery Across United Kingdom