Valtrex (Valacyclovir) is an antiviral drug used in the treatment of infections caused certain types of viruses. It is manufactured by GlaxoSmithKline. These viruses are related and are categorised as part of the herpesvirus family. The relevant ones in this family which Valtrex acts on are herpes simplex virus type I (HSV-1), herpes simplex virus type II (HSV-2), varicella zoster virus (VZV), Epstein-Barr virus (EBV) and cytomegalovirus.
Valtrex is used mainly to treat HSV. HSV-1 mainly causes cold sores – blisters which occur in or around the mouth. HSV-2 mainly causes genital herpes of which the symptoms are blisters around the genital or rectal area, pain when urinating and flu-like symptoms.
VZV is the virus that causes chicken pox which later on in adult life leads to shingles (herpes zoster). Valtrex is sometimes used to treat the symptoms of chickenpox and shingles.
In patients who have undergone organ transplant surgery they may be prescribed Valtrex to prevent contracting cytomegalovirus.
Valtrex works by slowing down growth and spread of the virus in the body. It does not cure the virus but gives the immune system to fight of the virus by slowing down the growth of the virus. As a result of this patients will experience less symptoms.
The dose sizes of Valtrex are 250 mg, 500 mg, and 1000 mg (1 gram). It can be taken with or without meals. Patients taking Valtrex should also ensure they drink plenty of fluids to prevent any problems that may occur with their kidneys. The recommended dose for cold sores is 2000 mg every 12 hours daily. It should be taken from the start of cold sore symptoms such as burning or itching in the mouth area. For genital herpes the recommended dosage is 1000 mg twice daily for 10 days. It is best to be taken early from the first 48 hours of the symptoms occurring. For treatment of shingles the dose is 1000 mg three times a day for seven days.
The side effects of Valtrex include dizziness, indigestion or stomach pain, fatigue, joint pain, a mild skin rash, blocked nose or a sore throat. Other side effects which warrant calling a doctor and to stop taking Valtrex include pain in the lower back, swelling, weight gain, difficulty breathing or short of breath from mild exertion, mood changes (such as being easily confused, aggressive and hallucinations), seizures, impaired speech or vision, bloody diarrhea, vomiting, pale coloured skin.
Valtrex may interact with other drugs such as nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen.