Valaciclovir

Valaciclovir tablets are antiviral medicines used to treat common viral infections like cold sores. Valaciclovir is the generic name of the medicine but it is also available as the brand name Valtrex. Both medicines contain the same active ingredient valaciclovir, and they both work in the same way to treat viral infections.

Cold sores are small blisters that can appear around your nose, lips or mouth. They are caused by a type of virus known as HSV (herpes simplex virus). They can be easily passed on from person to person during direct and close contact, like kissing.

At first, after getting infected with the virus, you may not have any symptoms right away because the virus is usually dormant (inactive) for a while. You may experience your first outbreak of symptoms later, especially if you are exposed to certain triggers.

It is very common to experience recurrent infections with cold sores although the symptoms are less severe and for a shorter period of time. About 1 in 5 people in the UK experience recurrent cold sore infections.

Some common triggers for cold sores are:

• fever
• other types of chest infections
• sunlight exposure
• stress
• menstruation (monthly periods)
• tiredness

Some symptoms of cold sores may include:

• burning, tingling and painful sensation around the affected area
• cold sore blisters which burst and form crusty scabs
• sore throat with or without swollen glands
• halitosis (bad breath)

Cold sores usually clear up within 10 days without treatment, but if your symptoms become unbearable, there are antiviral medicines like valaciclovir which can help ease your symptoms and speed up healing.

Valaciclovir and aciclovir are similar antiviral medications which both work effectively to treat infections caused by the herpes simplex virus (HSV), like genital herpes and cold sores.

The main differences are in their active ingredients and dosage for treating viral infections. The main difference is that you only need to take your valaciclovir dose twice a day, compared to the aciclovir dose that is taken 3 times a day.

Another difference is the active ingredient in valaciclovir is valaciclovir hydrochloride, while the active ingredient in aciclovir is aciclovir. Valaciclovir is converted into aciclovir when it is inside your body, before it begins to work.

It is important you take valaciclovir as prescribed by your doctor to treat cold sores. The dosage to treat cold sores is one 500mg valaciclovir tablet to be taken twice a day for 5 days, leaving at least 12 hours between each dose.

You should swallow your valaciclovir tablets whole with water. If you are over 65 years of age or have kidney problems, you should try to drink water regularly, to reduce side effects.

If you forget to take valaciclovir when you should, take it as soon as you remember. If it is nearly time for your next dose, skip the missed dose and take the next dose as planned. Do not take a double dose to make up for a missed dose.

Other treatments available to manage the symptoms of cold sores include:

• cold patches
• antiviral creams
• other antiviral medicines
• painkillers

Other ways you can manage the symptoms of cold sores include:

• eating cool and soft foods
• drinking lots of fluids to prevent dehydration
• avoiding picking the sores so they do not become infected
• strengthening your immune system by eating healthily, exercising and getting enough sleep

Cold sore treatments are usually most effective when used as soon as you start to notice or feel symptoms.

You may experience some side effects when taking valaciclovir.

Some common valaciclovir side effects may include:

• feeling sick
• headache
• diarrhoea
• dizziness
• itching

Some rare valaciclovir side effects include:

• feeling confused
• tremors
• agitation
• low back pain
• stomach pain
• fits
• kidney problems

Tell your doctor if you experience any of these side effects. The patient information leaflet supplied with your medicine pack contains more information about all known valaciclovir side effects, cautions and drug interactions.

Stop taking valaciclovir and seek medical attention if you experience fever, swollen lymph nodes, or rashes. These may be symptoms of a serious reaction to valaciclovir, known as DRESS syndrome (Drug Reaction with Eosinophilia and Systemic Symptoms).

Stop taking valaciclovir and seek medical attention if you have any signs of an allergic reaction including:

• chest tightness
• difficulty breathing
• swollen lips, mouth, neck or throat
• itchy skin rash

Valaciclovir may not be suitable for certain groups of people. In some cases, your doctor may need to adjust your valaciclovir dose if you have certain conditions or are taking certain medications.

Tell your doctor before taking valaciclovir if you:

• are pregnant or breastfeeding
• are allergic to any of the ingredients in valaciclovir
• have kidney problems
• have liver problems
• have a weak immune system

You doctor may need to adjust your valaciclovir dose if you:

• are over 65 years
• have kidney problems
• have a weak immune system

Tell your doctor if you are taking any other medications including herbal medicines and over the counter medications. Tell your doctor if you are taking medicines which may affect your kidneys.

These may include:

• methotrexate
• ciclosporin
• aminoglycosides
• foscarnets
• pentamidine
• tacrolimus