Valtrex

Valtrex is an antiviral medication used to treat herpes simplex viruses, including genital herpes (herpes simplex strain 2, HSV-2) and cold sores (herpes simplex strain 1, HSV-1). It also treats varicella zoster virus (VZV, herpes zoster), which causes chickenpox and shingles. It is also used to prevent infections in those who are immunocompromised, including preventing CMV (cytomegalovirus) in those who’ve had organ transplants.

It is an oral prescription in the form of capsules that can offer relief from unpleasant blisters within 24 hours as well as significantly reduce the duration of your outbreak. Treatment is most effective when used at the first sign of infection.

Valtrex contains the active ingredient valaciclovir (valacyclovir) hydrochloride which belongs to a group of drugs known as 'prodrugs'. This means that it changes and adapts when it's inside the body to become more effective. When valaciclovir is absorbed into the system, it evolves into is parent drug aciclovir (acyclovir) which allows more of the active ingredient to be absorbed into the system and ensure effective treatment.

Valtrex works specifically by targeting the virus cells responsible for the growth and duplication of the viral DNA. This prevents the virus from duplicating itself and spreading from one healthy cell to another. It allows your body's natural defences to fight back, and drive the virus back to an inactive state.

Each tablet is 500mg, but the dosage will depend on the form of herpes and whether you’re treating an initial bout, a recurrent bout or preventing infection. Your dose may also be adjusted if your symptoms persist after you complete your course or you have a weak immune system, kidney problems or are over the age of 65.

Valtrex should always be taken for the full course, regardless of whether the symptoms subside during the course.

• for treatment of an initial genital herpes infection - take one 500mg tablet twice a day for 5 days
• for the treatment of an initial cold sores infection - take four 500mg tablets then take another 4 tablets after 12 hours, you should only take Valtrex for one day for cold sores
• for the treatment of shingles - take two 500mg tablets 3 times daily for 7 days
• for the treatment of recurrent genital herpes and cold sores infections - take one 500mg tablet twice daily for 3 - 5 days
• for the prevention of genital herpes and cold sores infections - take one 500mg tablet once a day for 6-12 months

It is also advised to drink plenty of fluids whilst taking this medication to avoid dehydration. You should swallow the tablets whole, do not crush, break or split tablets.

If you miss a dose, do not take a double dose. If it is nearly time to take your next tablet, just take your next scheduled dose as normal until the treatment finishes. If you remember long before your next dosage, take the tablet as soon as possible.

As with all prescription medication, there is a small risk of side effects. However, the most common side effects are usually mild and go away on their own within a few days.

Common side effects include:

• headache
• nausea (feeling sick)
• vomiting (being sick)
• dizziness
• diarrhoea
• skin reactions including a rash and itching
• feeling confused or agitated
• tiredness

If you experience any of the following more severe symptoms, you may be experiencing an allergic reaction.

Symptoms of an allergic reaction may include:

• skin flushing, itchy skin rash
• swelling of the lips, face, neck and throat which causes difficulty breathing
• sudden drop in blood pressure, leading to collapse

More severe side effects of Valtrex are rare, but symptoms should not be ignored. If you experience any severe side effects, you should stop taking Valtrex and seek immediate medical attention.

For a full list of side effects, please refer to the patient information leaflet which is available to download on this page and will be sent in the box with your medication.

If you have previously had an allergic reaction to the active ingredient valaciclovir or the similar antiviral aciclovir, then you should not take this medication. Equally, if you are pregnant or breastfeeding, it is recommended that you speak to your doctor for an alternative.

Some groups of people should take particular caution before taking this medication and should speak to their doctor beforehand as you may be more at risk of side effects. This includes those who:

• are 65 years or older
• have kidney problems
• have liver problems
• have a weak immune system

If you are not sure if any of the above apply to you, then you should consult with a healthcare professional before taking this medication.

In addition, once contracted, the herpes virus does not leave your body and can be transferred to partners at any time. Refraining from sex during outbreaks and making sure you are containing the virus is essential.

You should always inform whoever is prescribing you if you take any other medicines, this includes prescription, over-the-counter and herbal medicines. This is because your treatment may be affected.

The following medicines can affect kidney function when taken with Valtrex:

• aminoglycosides - a class of antibiotics
• platinum-based chemotherapy drugs
• methotrexate - immunosuppressant used to treat cancer and autoimmune diseases
• pentamidine - used to prevent serious lung infections
• foscarnet - antiviral used to prevent CMV
• ciclosporin - immunosuppressant used treat rheumatoid arthritis, Crohn’s disease, psoriasis and prevent organ rejection after transplant
• tacrolimus - immunosuppressant used to prevent organ rejection after transplant
• cimetidine - for stomach ulcers
• probenecid - for gout

If you are not sure what medication you take, you should speak with your doctor before taking Valtrex.

Valtrex 500mg is available to purchase on prescription at HealthExpress for the treatment of genital herpes, cold sores and shingles. To make sure you are suitable for treatment, you will have to fill out a quick and confidential medical questionnaire reviewed by one of our registered doctors. Once approved, your medication will be dispensed and dispatched discreetly to your address with next-day delivery.