What is Aciclovir and how does it treat cold sores?
Aciclovir is an antiviral medication used to treat the herpes simplex virus and other closely related viruses, such as chicken pox or shingles. It stops the spreading of the herpes virus in the body by interrupting the process of virus replication thereby reducing the duration of the infection. It is not a cure for these infections, as the virus continues to live in the body even after an outbreak but Aciclovir reduces the severity and length of the outbreak.
How do I take Aciclovir?
Aciclovir should be swallowed with water three times a day for 5 days. The treatment is most effective when you use it at the first signs of outbreak.
How effective is Aciclovir?
If Aciclovir taken as soon as a herpes outbreak has begun, Aciclovir can reduce the duration and severity of the outbreak. It can also suppress recurring outbreaks by 80%.
How fast does it work?
How quick and well Aciclovir work will depend on the severity of your symptoms and how soon you notice the symptoms before starting treatment. As soon as you start to notice the symptoms, it is best to start taking Aciclovir. You should consult with your doctor as soon as you spot an outbreak.
Do I need to seek medical advice before taking Aciclovir?
If you are pregnant, breastfeeding, elderly or suffer from kidney problems it is best to seek medical advice before taking Aciclovir.
Cold Sore Treatment
What are cold sores and how do you get them?
Cold sores are blisters which occur on the mouth and lips caused by the herpes simplex virus. It is caught when you come into contact with people with the infection. The virus usually remains dormant under the skin but often when your immune system weakens through stress or illness, the virus will reactivate.
Herpes - Herpes is the name given to a family of viral infectious diseases. The most common virus within this family is Herpes Simplex Virus (HSV), the cause of oral and genital herpes. Symptoms include:
- Red bumps around the mouth and lips, which develop into painful crusty sores
What do cold sores look like?
Cold sores develop in different stages:
- Tingling, itching or burning sensation.
- Small fluid blister(s) start to form.
- The blister will fill with fluid and bust.
- The scab formed will slowly heal within the next few days.
What triggers cold sores to appear?
Common triggers include:
- Infection (e.g. cold or flu)
- High fever
- Injury to the lip or mouth
- Being tired/exhausted
- Hormonal changes
- Exposure to sunlight
Once you’ve been exposed to a cold sore, the likelihood of it recurring is higher, but looking after your health and knowing what your cold sore triggers are, you will find it easier to avoid future outbreaks.
Are cold sores contagious?
The herpes simplex virus which cause cold sores are extremely contagious from the moment you first feel the tingling sensation until the time it has healed.
Do’s/Don’ts of having a cold sore:
- Drink plenty of fluids to avoid dehydration
- Wash your hands before and after applying the cream
- Use lip balm with SPF 15 or above
- Eat cool, soft foods
- Take painkillers to ease pain and swelling
- Do not touch your cold sore
- Do not kiss anyone when you have a cold sore
- Do not share anything you come into contact with (e.g. creams, cutlery, lipstick)
- Do not eat salty, acidic food
- Do not have oral sex until your cold sore has completely healed
The most common side effects of Aciclovir are:
- Abdominal pain
- Dizziness and headache
- Skin rashes
Always read the patient information leaflet before commencing treatment.
Important: We advise you to always read the patient information leaflet inside the medication box, as the generic medication may not always entirely match the patient information leaflet listed. Please contact us if you have any questions.
Written and reviewed by our qualified team
Find out more about how we ensure the accuracy of our content with our content guidelines.
Content last updated: 05 Dec 2023