Aciclovir

Aciclovir is an antiviral medication used to treat genital herpes outbreaks. Aciclovir tablets are also used for:

• chickenpox and shingles
• cold sores and other herpes simplex infections
• suppressing further outbreaks of genital herpes

Aciclovir is a generic medication. It is the same as the branded medication, Zovirax. They both contain the active ingredient aciclovir and work in the same way but have different names. Branded medications are generally more expensive than generic ones.

What is genital herpes?

Genital herpes is caused by the herpes simplex virus (HSV). The virus causes an outbreak of blisters in the genital or anal regions. It’s commonly caused by the herpes simplex virus type 2 (HSV-2) but can also be caused by herpes simplex virus type 1 (HSV-1). HSV-1 often causes cold sores.

Genital herpes symptoms include:

• small red blisters that can be sore and open
• burning, itching, or tingling around the genitals
• pain when you pee
• an abnormal vaginal discharge in women

Aciclovir works by stopping the growth of the herpes simplex virus. By stopping the virus from multiplying, it helps to reduce symptoms and stops the infection from spreading while your body fights it off.

Aciclovir can treat outbreaks of genital herpes, but it’s not a cure. There’s a chance of getting further outbreaks, but how often these happen is different for each person.

How quickly does aciclovir work?

Aciclovir starts working within a few days of being used for a first or recurrent outbreak and you may notice your symptoms getting better within 24 to 48 hours.

If you’re taking aciclovir to prevent recurrent genital herpes outbreaks, it will continue to work for as long as you take it.

You should take aciclovir tablets by mouth, swallowing them whole with a glass of water. Or, you can dissolve the tablet in a glass of water and stir before drinking. Take aciclovir as soon as possible after your symptoms appear.

What to do if you take too much

If you take more aciclovir than you have been prescribed, you should speak to your doctor for advice. It is not usually harmful unless you take too much over several days.

What to do if you miss a dose

If you forget a dose you should take it as soon as you remember, unless it is nearly time to take your next dose. In this case, skip the missed dose entirely. Do not take a double dose to make up for the missed dose.

Aciclovir dosage

The dosage of aciclovir you require will depend on whether you have genital herpes symptoms right now. The usual dose for the first episode of genital herpes is 400mg, 3 times per day, for up to 10 days. If you have more outbreaks after the first, 400mg is used 3 times a day for 5 days.

Aciclovir tablets can also be used to prevent outbreaks. This is recommended for people who have 6 or more outbreaks in a year, or whose outbreaks are very severe when they happen. This is called suppression treatment. For this, aciclovir 400mg is taken twice a day for 6 to 12 months.

When should I start taking aciclovir?

You should start taking aciclovir as soon as you notice symptoms of an outbreak. The sooner you take it, the quicker your symptoms will go away.

If this is your first outbreak, check our guide on what genital herpes looks like for more information. If you aren’t sure, it’s best to speak to a doctor or visit a sexual health clinic as soon as possible.

What should I do if I want to stop taking aciclovir?

Don’t stop taking aciclovir unless your doctor tells you to. Even if your symptoms get better or you can’t see any sores on your genitals, it’s important to finish your treatment.

In clinical trials, aciclovir was found to be effective for those having an initial genital herpes outbreak or a recurrent outbreak. Patients in the trial who took aciclovir tablets rather than a placebo reported that it:

• significantly reduced the duration of symptoms such as ulcers, itching, and pain
• improved how long it took to completely heal
• reduced the amount of new sores formed

Genital herpes outbreaks can last a few days to a few weeks. Aciclovir can reduce the duration of your outbreaks, especially if taken at the first sign of symptoms.

Aciclovir tablets can cause some side effects, although most are likely to be mild and should go away within a few days of treatment. Speak to your doctor if you get any side effects that are severe or are affecting your daily life.

Common side effects of aciclovir tablets include:

• nausea or vomiting (feeling or being sick)
• diarrhoea
• dizziness
• feeling tired (fatigue)
• headaches
• unexplained high temperature (fever) and feeling faint, especially on standing
• itching
• rash
• skin reaction when exposed to light (photosensitivity)
• stomach pain

Uncommon side effects of aciclovir tablets include:

• hair loss
• itchy, hive-like rash

Rare side effects of aciclovir tablets include:

• increased liver enzymes
• effects on some blood and urine tests

Very rare side effects of aciclovir tablets include:

• allergic reaction
• difficulty speaking
• feeling weak
• feeling agitated or confused
• shaking or tremors
• fits (seizures)
• hallucinations (seeing things)
• kidney problems where you pass little or no urine
• liver inflammation (hepatitis)
• low numbers of red blood cells (anaemia)
• low numbers of white blood cells (leukopenia)
• low numbers of blood platelets (thrombocytopenia)
• pain in the lower back, kidney area of the back, or just above the hip (renal pain)
• stiff neck and sensitivity to light
• unconsciousness
• yellowing of the skin and whites of the eyes (jaundice)
• feeling unusually sleepy or drowsy
• unsteadiness when walking and lack of coordination
• inability to think or judge clearly
• paralysis of part or all of your body
• disturbances of behaviour, speech, and eye movements

If you have any of these rare side effects you should stop taking aciclovir tablets and see a doctor straight away.

While taking aciclovir tablets you should refrain from sexual activity as you could pass herpes on to your sexual partner. You can catch genital herpes from oral, anal, or vaginal sex.

You should speak to your doctor if you are pregnant, planning on getting pregnant, or breastfeeding before taking aciclovir.

Aciclovir can be taken by adults up to the age of 65. If you are over 65 years old, you should speak to your doctor before taking aciclovir.

Do not take aciclovir tablets if you are allergic to aciclovir or any other ingredients in the tablets. If you have kidney problems, your doctor will assess whether aciclovir is suitable or if you need additional monitoring during treatment.

Aciclovir is known to interact with some medicines, including:

• probenecid for gout
• cimetidine for stomach ulcers
• mycophenolate mofetil, a treatment for stopping rejection of transplanted organs

You should tell your doctor about any prescription or non-prescription drugs you are taking before taking aciclovir, including herbal remedies.

If you want to find out more, please read the patient information leaflet.

Because aciclovir can make you feel tired or drowsy, it may impair your ability to concentrate and react. If you are affected, do not drive or operate machinery.

You can get aciclovir tablets online from trusted and regulated websites such as Asda Online Doctor. We can provide a doctor’s prescription and treatment – you can start your request by completing a short online questionnaire about your symptoms and health. If suitable, aciclovir can be delivered to your home or collected from an Asda Pharmacy.

Can you get aciclovir tablets on the NHS?

Yes, you can get aciclovir tablets on the NHS. You’ll need to see your GP or visit a local sexual health clinic.

Can you get aciclovir tablets over the counter?

No, aciclovir tablets are only available via a prescription.

There are 3 main treatment options available for genital herpes, which are:

• aciclovir
• valaciclovir – a pro-drug, which means your body converts it into aciclovir after you have taken it. Works in the same way as aciclovir.
• famciclovir – another antiviral medication that can be used as an alternative if you can’t take aciclovir.

If you are not sure if you have herpes, you can take a genital herpes test at home.

Aciclovir cream

As well as tablets, aciclovir is available in a cream that is used to treat cold sores. Aciclovir cream is not usually recommended to treat genital herpes.