Prescription Cold Sores Treatments

Cold sores are highly contagious and can be caught by others easily. Cold sores are not inherently dangerous, however they can cause complications for people with weakened immune systems. This includes babies and small children, HIV patients and cancer patients undergoing chemo or radiotherapy. 

You should be careful not to spread the virus to others. To minimise the risk of spreading the virus:

• Do not touch your sores
• Wash your hands before and after applying cold sore creams 
• Do not share your medication with anyone
• Don't share other things such as cutlery, cups, lipsticks etc. 
• Avoid kissing and oral sex

Cold sores are caused by the herpes simplex virus. You can catch the virus through skin-to-skin contact with an infected person. Kissing is the main way cold sores are passed on, however the virus can also be sexually transmitted. Once the virus is in your body you will have it for life. The WHO estimates that 67% of people are carriers of the herpes simplex virus. It remains dormant in your nervous system and can occasionally flare-up causing cold sores. There is no cure for herpes simplex, however outbreaks can be treated.

Triggers that may cause cold sores to appear include:

• A weakened immune system, which can occur when your body is fighting other infections like the cold
• Certain medications
• Stress
• Fatigue
• Hormone changes
• Injury to the lips/mouth
• Exposure to sunlight

The triggers are different from person to person and you may come to recognise and therefore better avoid your own triggers over time.

The virus that causes cold sores on the face can also affect the eyes and genitals. You should contact your GP  for treatment in these cases.

Cold sores will usually go away themselves within 10 days, however treatments are available to speed up healing and reduce the severity of symptoms. Antiviral medication that targets the herpes simplex virus that causes cold sores is available to buy and on prescription. It can come in the form of a cream that is applied to the lips or as oral tablets which can be taken for more severe or painful outbreaks.

About Aciclovir cream

Aciclovir cream, also known as Zovirax is available to buy without a prescription. 

Apply to the lips five times a day. The cream works best when started at the first sign of tingling before blisters appear.

About Aciclovir tablets

Aciclovir tablets are available on prescription when you suffer from more painful or severe outbreaks of cold sores. They contain the same drug as the cream but once swallowed they get to work fighting the virus from the inside of your body. 

For outbreaks, you take one tablet FIVE times a day for 5 days. If the cold sore hasn’t healed after 5 days please contact your doctor as you may require further treatment.

The tablets can be used along with the cream which may better help soothe skin symptoms. 

As with all viral infections, you should make sure you keep well hydrated when fighting cold sores. 

Patient information leaflet:

https://www.medicines.org.uk/emc/files/pil.4334.pdf

About Valaciclovir

Valaciclovir works the same way as aciclovir but with the advantage of needing to swallow fewer tablets. 

With valaciclovir, you only take one tablet twice a day for 5 days. If the cold sore hasn’t healed after 5 days please contact your doctor as you may require longer treatment.

Valaciclovir tablets can be used along with aciclovir cream which may better help soothe skin symptoms.

As with all viral infections, you should make sure you keep well hydrated when fighting cold sores.

Patient information leaflet:

https://www.medicines.org.uk/emc/files/pil.4349.pdf

Alternative treatments

Cold sores can be treated using hydrocolloid dressings (Compeed invisible cold sore patches) which is available in most pharmacies. To treat the blisters, an anaesthetic cream can be applied to them and oral painkillers can be taken to ease any pain or discomfort.

Without treatment, cold sores usually take 7-10 days to heal in healthy adults.

Side effects

Side effects from aciclovir creams are quite rare, however you should read the patient information leaflet for full information.

Aciclovir tablets:

Common side effects (affects 1-10% of the population)

• Headache
• Dizziness
• Nausea/vomiting
• Diarrhoea
• Abdominal pain
• Itching/rash
• Fever
• Fatigue

For a full list of side effects, please read the patient information leaflet.

https://www.medicines.org.uk/emc/files/pil.4334.pdf

Valaciclovir:

Very common side effects (affects more than 10% of the population)

• Headache

Common side effects (affects 1-10% of the population)

• Nausea/vomiting
• Diarrhoea
• Abdominal pain
• Dizziness
• Itching/rash

For a full list of side effects, please read the patient information leaflet.

https://www.medicines.org.uk/emc/files/pil.4349.pdf

The first sign of a cold sore is usually a tingling, itching or burning feeling on the lips or surrounding areas. If you are known to get cold sores then you should start treatment as soon as you sense this tingling feeling. 

Small fluid-filled blisters then appear on your lips or face, however if treatment is started early blisters can be kept to a minimum and even avoided in some cases. Once blisters appear there is little advantage gained from starting treatment unless in severe infections.

A golden/yellow crust around the blisters is a common symptom of cold sores. The gold crust is caused by a bacterial skin infection called impetigo. Impetigo can be treated with fusidic acid cream from a pharmacy but it will usually go away itself after the cold sore heals.